Species Card of Copepod
Calanoida ( Order )
    Diaptomoidea ( Superfamily )
        Acartiidae ( Family )
            Acartia ( Genus )
                Acanthacartia ( Sub-Genus )
Acartia (Acanthacartia) tonsa  Dana, 1849   (F, M)
Syn.: Acartia giesbrechti Dahl, 1894 c (p.13, 22, Rem.: Mouth of the Tocantins River, in the lower salinities 5.69 to 34.5 p.1000); Steuer, 1915; 1923 (p.23, figs.F,M); Björnberg, 1963 (p.66, Rem.);
? Acartia bermudensis Esterly, 1911 b (p.224, figs.F,M); Owre & Foyo, 1967 (p.101, figs.F,M);
? Acartia floridana Davis, 1948 (p.82, figs.F,M);
Acartia tonsa cryophylla Björnberg, 1963 (p.64, figs.F,M);
Acartia gracilis Herrick, 1887;
Acartia tonsa s.l. : Brinton & al., 1986 (p.228, Table 1).
Giesbrecht, 1892 (p.508, 522, 770, figs.F,M); Giesbrecht & Schmeil, 1898 (p.154); Wheeler, 1901 (p.183, figs.F,M); Esterly, 1905 (p.204, figs.F,M); Sharpe, 1910 (p.414, fig.F); Steuer, 1923 (p.23, figs.F,M); Esterly, 1924 (p.105, figs.F,M); Remy, 1927 a (p.171, figs.F,M, Rem.); Wilson, 1932 a (p.160, figs.F,M); Rose, 1933 a (p.276, figs.F,M); Redeke, 1934 (p.39, figs.F, Rem.); Davis, 1944 (p.3); Farran, 1948 a (n°12, p.3, figs.F); Brodsky, 1950 (1967) (p.426, figs.F,M); Carvalho, 1952 a (p.152, Rem.M); ); Conover, 1956 (p.156 & suiv., figs.N, juv.); Anraku & Omori, 1963 (p.118, figs. mouth parts); Vervoort, 1964 a (p.24); 1965 (p.198, Rem.); Bowman, 1965 (p.150: Rem.); Gonzalez & Bowman, 1965 (p.257, figs.F,M, Rem.); Faber, 1966 p.191, fig.N); Ramirez, 1966 (p.19, figs.F,M); Marques, 1966 (p.10); Vidal, 1968 (p.41, figs.F,M); Pallares, 1968 b (p.29, figs.F, M); Ramirez, 1969 (p.84, fig.F, Rem.); Shih & al., 1971 (p.31); Arcos, 1975 (p.23, figs.F,M); Dawson, 1979 (1980) (p.1, figs.F,M); Dawson & Knatz, 1980 (p.8, figs.F,M); Miller & al., 1980 (p.349, figs. Md: F, juv.V); Brylinski, 1981 (p.255, figs.F,M, carte); Björnberg & al., 1981 (p.661, figs.F,M, Rem.); Sazhina, 1982 (p.1160, Rem., fig.N); Schnack, 1982 (p.89, figs.Mx2, Md, Mxp); Montu & Gloeden, 1982 (p.361, anomalies); Gaudy & Vinas, 1985 (p.227); Sazhina, 1985 (p.83, figs.N); Zamora-Sanchez & Gomez-Aguirre, 1986 (p.339, figs.F,M, Rem.); Blades-Eckelbarger, 1991 (p.262, fig.F); Sabatini, 1990 (p.53, figs.juv.1-5, F,M); Belmonte & al., 1994 (p.9, figs.F,M); Garmew & al., 1994 (p.149, Rem.); Mazzocchi & al., 1995 (p.65, figs.F,M, Rem.); Hassett & Blades-Eckelbarger, 1995 (p.59, fig., 3, gut morphology, gut cells, digestive activities); Behrends & al., 1997 (p.594, figs.F); Hoffmeyer & Prado Figueroa, 1997 (p.257, figs.); Chen & Marcus, 1997 (p.587, Rem: œuf); Belmonte, 1998 a (p.38, fig., Rem.: Eggs); Bradford-Grieve, 1999 (n°181, p.5, figs.F,M); Barthélémy, 1999 (p.858, 864, figs.F); 1999 a (p.9, Fig.23, K-M); Bradford-Grieve & al., 1999 (p.886, 962, figs.F,M); Castro-Longoria, 2001 (p.225, fig.4); Prusova & al., 2002 (p.65, figs.F,M); Caudill & Bucklin, 2004 (p.91: genetic diversity); Giesecke & Gonzalez, 2004 (p.607, fig.: Md); G. Harding, 2004 (p.24, figs.F,M); Ferrari & Dahms, 2007 (p.63, 71, Rem., Table VIII); Avancini & al., 2006 (p.115, Pl. 83, figs.F,M, Rem.); Vives & Shmeleva, 2007 (p.428, figs.F,M, Rem.); Chen G. & Hare, 1998 (p.1451, cryptic diversification); Chen & Hare, 2011 (p.2425, genetic); Harvey J.B.J. & al., 2012 (p.60, Table 2, molecular sequences); Laakmann & al., 2013 (p.862, figs.1, 2, 3, 5, Table 1, 2, molecular Biology); Blanco-Bercial & al., 2014 (p.5, 6: Rem.: problematic taxa)
Species Acartia (Acanthacartia) tonsa - Plate 1 of morphological figuresissued from : J.M. Brylinski in J. Plankton Res., 1981, 3 (2). [Fig.2, p.257].
Structure of P5 of the Acartia in the wet docks of the harbour of Dunkirk (Strait of Dover). Male and Female

a: Acartia clausi; b: A. tonsa, c: A. discaudata, d: A. bifilosa

c.f.: curved finger, c.n.: curved needle, d.t.: distal tooth, l.: lamella, l.p.: lamellar process, p.t.: proximal tooth, s.: setae, sp.: spines, 3, segment 3 of left leg.

Species Acartia (Acanthacartia) tonsa - Plate 2 of morphological figuresIssued from: M.G. Mazzocchi, G. Zagami, A. Ianora, L. Guglielmo & J. Hure in Atlas of Marine Zooplankton Straits of Magellan. Copepods. L. Guglielmo & A. Ianora (Eds.), 1995. [p.67, Fig.3.7.1].
Female: habitus (dorsal); B, urosome (dorsal); C, P5.
Nota: Proportional lengths of urosomites and furca 46:16:18:20 = 100.

Male: D, habitus (dorsal); E, urosome (dorsal); F, P5.
Nota: Proportional lengths of urosomites and furca 16:29:18:8:14:15 = 100.

Remarks: Both females and males of this species are hightly variable in the ornamentation of the urosomal somites. The specimens from Straits of Magellan resemble those described by Björnberg (1963) as A. tonsa var. cryophylla due to the remarkably reduced ornamentation of the urosome.

Species Acartia (Acanthacartia) tonsa - Plate 3 of morphological figuresissued from : P. Remy in Annales de Biologie Lacustre, 1926 (1927 a), XV. [p.172, Fig.I].
Female (from Ouistreham): 1, forehead (ventral), r = rostral filaments; 2, idem (lateral); 3, last thoracic segment (T) and 1st urosomal segment (A); 4, idem (lateral right side), s = seminal receptacle, S = spermatophore; 5, urosome (dorsal), F & F' = caudal rami; 6, P4.

Species Acartia (Acanthacartia) tonsa - Plate 4 of morphological figuresissued from : P. Remy in Annales de Biologie Lacustre, 1926 (1927 a), XV. [p.173, Fig.II].
Female (from Ouistreham): P5 (lateral view), (b = basal part; d = spinules; f = seta; m = muscles; p = lamellar process); 2, P5 (anterior view) (A and A' = basal segments).

Species Acartia (Acanthacartia) tonsa - Plate 5 of morphological figuresissued from : P. Remy in Annales de Biologie Lacustre, 1926 (1927 a), XV. [p.175, Fig.III).
Male: 1, urosome (dorsal) (1 = genital somite; F & F' = caudal rami); 2, P5 (anterior view) (d = distal segment of left leg).

Species Acartia (Acanthacartia) tonsa - Plate 6 of morphological figuresIssued from: M.G. Mazzocchi, G. Zagami, A. Ianora, L. Guglielmo & J. Hure in Atlas of Marine Zooplankton Straits of Magellan. Copepods. L. Guglielmo & A. Ianora (Eds.), 1995. [p.68, Fig.3.7.2].
Female (SEM preparation): B, urosome (dorsal), with a rows of small spinules on genital somite; C, detail of inner posterior margins of last thoracic somite (dorsal); D, urosome (lateral right side), with spermatophore attached to genital somite.; E, detail of spermatophore; F, P5; G, detail of distal end of P5.
Bars: B, D 0.050; C, E, G, 0.010 mm.

Species Acartia (Acanthacartia) tonsa - Plate 7 of morphological figuresIssued from: M.G. Mazzocchi, G. Zagami, A. Ianora, L. Guglielmo & J. Hure in Atlas of Marine Zooplankton Straits of Magellan. Copepods. L. Guglielmo & A. Ianora (Eds.), 1995. [p.69, Fig.3.7.3].
Female (SEM preparation): B, urosome (dorsal); C, idem (ventral); D, P5 (posterior); E, right P5; F, detail of last segment of left P5.
Bars: B, C 0.050 mm; D, E, F 0.010 mm.

Species Acartia (Acanthacartia) tonsa - Plate 8 of morphological figuresissued from : Giesecke & Gonzalez in Rev. Chil. Hist. Nat., 2004, 77. [p.610, Fig. 2 A]. Schematic drawing of the cutting edge of the left mandible blade of Acartia tonsa from Mejillones Bay, Chile .
Mean (SD: standard deviation in parenthesis) Itoh's edge index: 896 (43), n = 14 specimens.
Scale bar = 0.010 mm.
Based on the Itoh index, the species belong to \"Type II\", a group that utilizes both suspension and raptorial feeding modes to capture particles and zooplankton. The edge index would include this species into the omnivorous, with certain tendancy to carnivory (due to the proximity of the index to 900). Vargas & Gonzalez (2004) estimated that heterotrophic prey (microzooplankton) could contribuate to 1/3 of the total ingested carbon and the other 2/3 would be provided by autotrophic prey.

Species Acartia (Acanthacartia) tonsa - Plate 9 of morphological figuresissued from : F.C. Ramirez in Contr. Inst. Biol. mar., Buenos Aires, 1969, 98. [p.80, Lam. XVI, fig.135 ].
Female (from off Mar del Plata): 135, P5.
Scale bar in mm: 0.05.

Species Acartia (Acanthacartia) tonsa - Plate 10 of morphological figuresissued from : F.C. Ramirez in Bol. Inst. Biol. Mar., Mar del Plata, 1966, 11. [Lam.VI, Figs.8-14]
Female (from off Mar del Plata): 8, habitus (lateral right side)10, P5; 11, urosome (lateral left side); 12, idem.

Male: 9, urosome (dorsal); 13, habitus (dorsal); 14, P5.

Species Acartia (Acanthacartia) tonsa - Plate 11 of morphological figuresissued from : W. Giesbrecht in Fauna Flora Golf. Neapel, 1892, 19. [Taf.43, Fig.6].
Male: 6, urosome (dorsal).

Species Acartia (Acanthacartia) tonsa - Plate 12 of morphological figuresissued from : W. Giesbrecht in Fauna Flora Golf. Neapel, 1892, 19. [Taf.30, Fig.7].
Male: 7, right A1 (segments 18 and 19-21).

Species Acartia (Acanthacartia) tonsa - Plate 13 of morphological figuresissued from : W. Giesbrecht in Fauna Flora Golf. Neapel, 1892, 19. [Taf.30, Fig.24].
Female: 24, P5.

Species Acartia (Acanthacartia) tonsa - Plate 14 of morphological figuresissued from : W. Giesbrecht in Fauna Flora Golf. Neapel, 1892, 19. [Taf.30, Fig.34].
Male: 34, P5.

Species Acartia (Acanthacartia) tonsa - Plate 15 of morphological figuresissued from : C.O. Esterly in Univ. Calif. Publs Zool., 1924, 26 (5). [p.106, Fig. N).
Female (from San Francisco Bay): 1, forehead (lateral); 2, A1 (ventral); 3, forehead (ventral); 4, outline of posterior margin of thorax, to show spines; 5, margin of thorax and genital segment (lateral); 6, outline of posterior margin of thorax (lateral); 7, genital segment (ventral); 8, terminal part of Mxp; 9, habitus (lateral); 10, idem (dorsal); 11, urosome (lateral); 12, P4; 13, P3; 14, P2; 15, P1; 16, A2 (ventral); 17, 17-18, P5 (from side,; different specimens); 19, Md (citting edge); 20, P5.
Nota: Relative lenfths of abdominal segments and caudal rami 11:4:2:5. 1st and 2nd abdominal segments with row of small teeth on posterior border

Species Acartia (Acanthacartia) tonsa - Plate 16 of morphological figuresissued from : C.O. Esterly in Univ. Calif. Publs Zool., 1924, 26 (5). [p.107, Fig. O).
Male: 1, forehead (lateral); 2, urosome (dorsal); 3, habitus (dorsal); 4, grasping A1; 5, last thoracic and 1st abdominal segments; 6-7, outline of margin of last thoracic segment (lateral; different individuals) to show spines; 8, urosome (dorsal) from differnt specimen than in 2; 9, P1; 10, P5 (right foot at left); 11, end segment of left P5 (from a second specimen); 12-13, outlines of margin of last thoracic segment in two individuals, to show spines (lateral); 14, Segments of A1 proximal and distal to geniculation (proximal one at left); 15, terminal portion of Mxp; 16, urosome and margin of last thoracic segment (lateral).
Nota: Relative lengths of abdominal segments and caudal rami 22:32:18:6:9:15. 1st segment with tuft of hairs on each side; row of delicate hairs each side of last segment; posterior, dorsal margin of 2nd to 4th with row of small teeth which, in second, extend along sides.

Species Acartia (Acanthacartia) tonsa - Plate 17 of morphological figuresissued from : C.O. Esterly in Univ. Calif. Publs Zool., 1905, 2 (4). [p.204, Fig.49].
Female (from San Diego Bay): a, habitus (dorsal); d, P5.

Male: b, urosome (dorsal); c, P5 (dx = right foot).

Species Acartia (Acanthacartia) tonsa - Plate 18 of morphological figuresissued from : C.B. Miller, D.M. Nelson, R.L. Guillard & B.I. Woodward in Biol. Bull., 1980, 159 [p.350, Fig.1]. Scanning electron micrograph by A. Cornell-Bell.
Female (from NW Atlantic: Vineyard Sound, Massachusetts): Mandibular gnathobase of adult reared at 12.6 microMol silicic acid.
V = ventral tooth; C1 = large central tooth; C2 = smaller central tooth; L = limit of siliceous caps; N = nonsiliceous dorsal spine.
Black bar represents 10 microns.
Nota: A. tonsa has three siliceous teeth: a curving spine on the ventral end of the tooth list (V), a heavy crown with four rounded points in the center (C1), and a small bifurcate tooth just to right of center (C2). A. tonsa successfully extracted silicic acid from concentrations in seawater. Formation of normal teeth required concentration of 0.8 microMol or above. Copepodites and adults formed teeth at all of the silicic acid levels tested. However, typical specimens from low silicic-acid levels had teeth much lower in relief than those from high silicic-acid levels. This reduction was most evident in specimens from the 0.18 to 0.3 microMol concentrations. Reduction of teeth in specimens reared at low levels was variable both among individuals and among teeth on the same mandible. In a number of cases the ventral tooth was so reduced that in the SEM there appeared to be a hole completely through the siliceous structure to the chitin or tissue underneath (see Figure 2).

Species Acartia (Acanthacartia) tonsa - Plate 19 of morphological figuresissued from : C.B. Miller, D.M. Nelson, R.L. Guillard & B.I. Woodward in Biol. Bull., 1980, 159 [p.356, Fig.2]. SEM by A. Cornell-Bellbr.
Female: (Left figure) mandibular gnathobase of adult (reared at 0.22 microMol. silicic acid. The reduced ventral tooth is on the lower right. (Right figure) Detail of same jaw shows the character of the apparent hole in the ventral tooth.
The black bar represents 2.5 microns.

Species Acartia (Acanthacartia) tonsa - Plate 20 of morphological figuresissued from : C.B. Miller, D.M. Nelson, R.L. Guillard & B.I. Woodward in Biol. Bull., 1980, 159 [p.357, Fig.3]. SEM by A.H. Soeldner.
Female: Mandibular gnathobase of adult reared at 0.27 microMol. silicic acid. The central tooth shows severe reduction (the ventral tooth is at left).
The black bar represents 5 micons.

Species Acartia (Acanthacartia) tonsa - Plate 21 of morphological figuresissued from : C.B. Miller, D.M. Nelson, R.L. Guillard & B.I. Woodward in Biol. Bull., 1980, 159 [p.358, Fig.4]. SEM by A.H. Soeldner.
Female: (Above) Mandibular gnathobase from adult reared at 0.21 microMol. silicic acic. Both teeth show substantial, but not severe reduction. The ventral tooth is io the right. (Below) detail of central tooth shows the proximal-to-distal grooves usually on the surfaces of the teeth.
The black bar represents 2.5 microns.

Species Acartia (Acanthacartia) tonsa - Plate 22 of morphological figuresissued from : C.B. Miller, D.M. Nelson, R.L. Guillard & B.I. Woodward in Biol. Bull., 1980, 159 [p.360, Fig.5]. SEM by A.H. Soeldner.
Stage V: (Above) Mandibular gnathobase from copepodite reared at 0.21 microMol silicic acid. Both V and C1 show extreme reduction. (Below) Mandibular gnathobase from another copepodite reared at 0.21 microMol silicic acid. Neither V or C1 shows much wear.
The black bars represents 5 microns.
Nota: There is substantial reduction in one specimen, but not in other. Both the reduction and its variability occur in the younger stages as well as in adults.

Species Acartia (Acanthacartia) tonsa - Plate 23 of morphological figuresissued from : D.F.R. Arcos in Gayana, Zool., 1975, 32. [Lam.IX, Figs.71-74].
Female (from Bahia de Concepcion, Chile): 73, habitus (dorsal); 74, P5.

Male: 71, habitus (dorsal); 72, P5.

Species Acartia (Acanthacartia) tonsa - Plate 24 of morphological figuresissued from : R.-M. Bathélémy in J. Mar. Biol. Ass. U.K., 1999, 79. [p.861, Fig.4, K, L].
Scanning electon miccrograph. Female: K, genital double-somite (ventral); L, detail of the right genital slit.
Scale bars: 0.030 mm (K); 0.005 mm (L).
Symbols: * = cuticular protuberance; arrowhead = lamellar flap; small arrow = genital slit.

Species Acartia (Acanthacartia) tonsa - Plate 25 of morphological figuresissued from : G. Harding in Key to the adullt pelagic calanoid copepods found over the continental shelf of the Canadian Atlantic coast. Bedford Inst. Oceanogr., Dartmouth, Nova Scotia, 2004. [p.24].
Female & Male.

Nota: Female P5 basis with round process, apical segment not evenly tapered, toothed at center (arrowed).
Male left P5 apical segment with two digitiform appendages; right penultimate segment with no spines on process (arrowed)

Species Acartia (Acanthacartia) tonsa - Plate 26 of morphological figuresissued from : T.K.S. Björnberg in Bol. Inst. Oceanogr. Sao Paulo, 1963, XIII, 1. [p.65, Fig.34]. As Acartia tonsa var. cryophylla.
Female (from S Brazil): a, forehead; b, habitus (dorsal); c, last thoracic segment and urosome with spermatophore (right lateral); e, P5.

Male: d, last thoracic segment and urosome (dorsal); f, P5.

Nota: The abdomen of the female shows no spinulation along the margin of the abdominal segments; The P5 female have a longer marginal seta on the basal segment than the typical A. tonsa. The specimen is an indicator of cold southern water, therefore the name of the Brazilian new variety cryophylla (Salinity: 25.48-33.22 p.1000; temperatures: 14.38-15.40°C)

Species Acartia (Acanthacartia) tonsa - Plate 27 of morphological figures Ma. E. Zamora-Sanchez & S. Gomez-Aguirre in An. Inst. Univ. Nal. Auton. Mexico, 56 (1985), Ser. Zool. (2), 1986. [Pl.3, p.344].
Female (from Laguna de Agiabampo, Golf of California): 33, habitus (dorsal); 34, last thoracic segment and urosome (dorsal); 35, last thoracic segment and genital segment (lateral); 36, P5 (dorsal view).

Male: 37, habitus (dorsal); 38, last thoracic segment and urosome (dorsal); 39, last thoracic segment and urosomal segments 1-4 (lateral); 40, P5.

Species Acartia (Acanthacartia) tonsa - Plate 28 of morphological figuresissued from : J.K. Dawson in Harbors Environmental Projects, Univ. Southern California, 1979. [p.9, Fig.3].
Female (from Los Angeles Harbors): P5.

Species Acartia (Acanthacartia) tonsa - Plate 29 of morphological figuresissued from : J.K. Dawson in Harbors Environmental Projects, Univ. Southern California, 1979. [p.7, Fig.1].
Male: P5.

Species Acartia (Acanthacartia) tonsa - Plate 30 of morphological figuresissued from : J.K. Dawson in Harbors Environmental Projects, Univ. Southern California, 1979. [p.15, Fig.9, B, D].
Female : D, urosome (dorsal).

Male: B, urosome (dorsal).

Species Acartia (Acanthacartia) tonsa - Plate 31 of morphological figuresissued from : B.W. Hansen, G. Drillet, M.F. Pedersen, K.P. Sjøgreen & B. Vismann in J. comp. Physiol. B, 182. [p.616, Fig.1].
Subitaneous eggs of Acartia tonsa exposed to abrupt and substantial changes in salinity.
The eggs were transferred from normal salinity (32 psu) to 0 or 72 psu.
At zero salinity : A vitelline coat and chorion shell; B perivitelline space; C egg plasma membrane and D embryo.

Nota: When eggs kept at salinity 32 psu were abruptly exposed to hypo-saline conditions (0 psu), they swelled from about 80-90 micrometers in diameter, but they never exploded and they never hatched. Exposure of eggs to small, gradual changes in salinity was followed by changes in egg diameter and volume. The eggs exposed to 60 and 70 psu seawater imploded within 10 min whereas eggs exposed to 50 psu imploded after approximately 6 h.

After C.R, trancription from conductivity (psu) to ClNa: psu valor x 0.58; and conductivity to total salts: psu x 0.65.

Species Acartia (Acanthacartia) tonsa - Plate 32 of morphological figuresissued from : R.P. Hassett & P. Blades-Eckelbarger in Mar. Biol., 1995, 124. [p.60, Fig.1 partial]
Acartia tonsa (from Long Island Sound, New York). a, digestive system (drawn from digitized sagittal section) showing location of B-cells (arrowed). 1-3 midgut zones following terminology of Arnaud & al., 1978, e : aesophage; b-c, side and dorsal views, respectively, of adult female using differential interference contrast light microscopy, showing outline of gut epithelial layer and location of B-cells (arrowed)

Species Acartia (Acanthacartia) tonsa - Plate 33 of morphological figuresissued from : M. Anraku & M. Omori in Limnol. Oceanogr., 1963, 8. [p.122, Fig. 7, F]
Acartia tonsa (from Woods Hole): Cutting edge of Md.

Nota: The species has teeth of a somewhat different shape; some are sharp, others rounded.

Species Acartia (Acanthacartia) tonsa - Plate 34 of morphological figuresIssued from : J.M. Bradford-Grieve in ICES Identification Leaflets for Plankton N°181, 1999 [p.11, Figs.14 a-f].
Female: a, forehead (ventral) with rostral filaments; b, urosome (dorsal); c, P5.

Male: d, urosome (dorsal); e, P5; f, exopodal segments 2+3 of left P5.

Species Acartia (Acanthacartia) tonsa - Plate 35 of morphological figuresIssued from : K.G. da Costa, M. Vallinoto & R.M. da Costa in J. Coastal Res., 2011, SI 64. [p.362, Fig.2];
Phylogenetic ML tree based on 100 pseudore^licas of bootstrap.
Numbers represent ML/MP/IB.

Nota: The phylogenetic analyses produced similar tree topologies for all methods used, therefore, only the maximum likelihood tree is presented in the figure .
The consensus tree has 5 clades:
Clade I is composed of samples from Florida, and his the sister group of Clade II, which is made up of Chen & Hare's (2008) F-haplotypes from Chesapeake Bay. These clades are the sister group of Clade III (samples from Europe and Rhode Island), followed by Clade IV (Taperaçu, N Brazil) and Clade V (Chen & Hare's S haplotypes from North America).
Most of these clades are supported by high boostrap values, although the relationships between clades are not well-supported. The Shimodaira-Hasegawa test was used to examine different constrained topologies.
Genetic divergence btween the Taperaçu samples and the other clades varied between 21.6 % or 12.4 % (Clade III) and 28.7 % or 16.7 % (Clade I), according to the corrected and p distances respectively. However, including the outgroup , Acartia hudsonica (Ahu), these values increased to 37.8-47.7 % and 22.1-23.9 %.
The authors in the discussion (p.361) note that the identification of cryptic species has increased mainly because of the increasing availability of DNA sequencing technology (see Bickford & al., 2006).
Acartia tonsa is a widespread estuarine copepod, although recent studies of populations from the northwestern Atlantic and Europe have shown that the taxon may, in fact, represent a complex of cryptic species (see in Caudill & Bucklin, 2004; Drillet & al., 2008). While the species is cosmopolitan, these studies were restricted to North American and European populations.
The present study has identified what appears to be a new cryptic A. tonsa species from northern Brazil. The specimens analysed were highly genetically distinct from those of their counterparts recorded from other sites. Chen & Hare (2008) interpreted the divergence between S and F haplotypes as evidence of species-level differentition rather than an ancestral polymorphism. These divergent mtDNA haplotypes are also supported by a nuclear marker (ITS). The degree of divergence is typical of that found between recognized copepod species (see Bucklin & al., 2003; Chen & Hare, 2008).
No clear phylogeographic pattern was found in the present study, although additional analyses based on sequences with a relatively fast evolutionary rate may provide further insights.
irrespective of possible geographic patterns, the profound divergence among the clades indicates a multiple, and thus ancient origin of these cryptic species.
Using a 2% mutation rate, Chen & Hare (2008) concluded that the F and S lineages (clades II and V) split some 3.4 million years ago.
As a similar degree of divergence was observed between these lineages and the Taperaçu clade, it seems reasonable to conclude that they also split at around the same time. This indicates that the present-distribution of the species of the A. tonsa complex has been determined by ancient vicariant events.

Species Acartia (Acanthacartia) tonsa - Plate 36 of morphological figuresIssued from : K.G. da Costa, M. Vallinoto & R.M. da Costa in J. Coastal Res., 2011, SI 64. [p.361, Table 1];
Genetic divergence between the samples used in the present study.
P distance is presented, while corrected distance under the diagonal.

Nota: A 522 bp fragment of the mtCOI gene was obtained from specimens of Acartia tonsa collected in the Taperacu estuary in Bragança (N Brazil).
The sequences were aligned with a database obtained from GenBank, which included those of Europe and North America.
Two distinct haplotypes were identified. According to the AIC, the best-fit model of evolution was the K81uf+1 model (invariable site 0.6697), which was used to estimate genetic divergence.

Species Acartia (Acanthacartia) tonsa - Plate 37 of morphological figuresIssued from : N.H. Marcus in Mar. Biol., 1990, 105. [p.415, Fig.2, a].
Egg of Acaertia tonsa from sediment (coast of northern California, in February-April 1989).
Egg diameter (µm); 80.6 ± 1.8 (N = 10) (sediments, February); 81.0 ± 0 (sediments, April); 81.4 ± 1.8 (spawned, February).
Nota:: Egg surface with spines (spine lengths ranged from 18 to 25 µm)..

Species Acartia (Acanthacartia) tonsa - Plate 38 of morphological figuresIssued from : M.G. Mazzocchi in Guida al Riconoscimento del plancton dei Mari Italiani, Vol. II, 2006. [p.91, Tav. 83]. After A. Comaschi.
Female: a, forehead with rostral filaments ((ventral); b, habitus (dorsal); c, urosome (dorsal); d, same); e, last thoracic segment and urosome with spermatophore (lateral); f-g, left P5 (various aspects).

Male: h, habitus (dorsal); i-l, urosome (dorsal); m, P5; n, exopodal segments 2 + 3 (Re2+3) of left P5.

Compl. Ref.:
Esterly, 1917 (p.393, light-dark reactions); 1919 (p.1, 16, light-dark reactions); Sewell, 1948 (p.392, 461); Conover, 1956 (p.156, biology); Grice, 1956 (p.50); Deevey, 1956 (p.126, 127, tab. IV); Conover, 1959 (p.259, Table 1, 2, respiration); Deevey, 1960 (p.5, Table II, fig.8, 13, 14: annual abundance, Rem.: p.25, fig.18, 19) ; Bowman, 1961 (p.206, Rem.); H. Schulz, 1961 (p.57); Wickstead, 1962 (p.546, food & feeding); Marshall & Orr, 1962 (tab.1, 3); Grice & Hart, 1962 (p.287, table 3); Fagetti, 1962 (p.37); Cervigon, 1962 (p.181, tables: abundance distribution); Ahlstrom & Thrailkill, 1963 (p.57, Table 5, abundance); Gaudy, 1963 (p.29, Rem.); Anraku, 1964 a (p.221, grazing, predation); 1964 b (p.195, respiration-grazing v.s. temperature); Lance, 1965 (p.155, Table 1, 2, respiration vs osmotic pressure); Martin, 1965 (p.185, 188: Table 1); Faber, 1966 a (p.418, 419); Fleminger, 1967 a (tabl.1); Bishop, 1967 (p.23, predators); Hargrave & Geen, 1968 (p.332, phosphorus excretion); Emery, 1968 (p.293, swarm); Vinogradov, 1968 (1970) (p.106); Mullin, 1969 (p.308, Table I: estimates of production); Heinle, 1969 (p.186, temperature effect); 1969 a (p.150, Table 1, culture); 1970 (p.360, population dynamics); Itoh, 1970 a (p.8: tab.2); Reeve, 1970 (p.894, Rem.: p.901); Reeve & Cosper, 1970 (p.1, temperature effect); Wilson D.F. & Parrish, 1971 (p.202, mating); Zillioux & Gonzalez, 1972 (p.217, egg dormancy); Björnberg, 1973 (p.354, 384); Heinrich, 1973 (p.95, fig.1); Arndt & Heidecke, 1973 (p.599, 603); Mullin & Evans, 1974 (p.902, efficieny in food chain); Wilson D.S., 1974 (p.909, food size selection); Arashkevich, 1975 (p.351, fig.2, digestion time); Anderson G., 1975 (p.747, parasited by epidarid isopod); Peterson & Miller, 1975 (p.642, 650, Table 3, interannual abundance); 1976 (p.14, Table 1, 2, 3, abundance vs interannual variations); Uye & Fleminger, 1976 (p.253, resting egg, hatching); Grahame, 1976 (p.219, Table X); Arcos, 1976 (p.85, Rem.: p.97); Roman, 1977 (p.149, feeding); Peterson & Miller, 1977 (p.717, Table 1, seasonal occurrence); Miller & al., 1977 (p.326, growth); Ikeda, 1977 b (p.29, respiration rate); Richman & al., 1977 (p.69, grazing); Reeve & Walter, 1977 (p.211, grazing vs food concentrations); Allan & al., 1977 (p.317, grazing); Honjo & Roman, 1978 (p.45, fecal pellet, sinking rate); Parrish & Wilson, 1978 (p.65, fecundity); Knatz, 1978 (p.68, Table 1, fig.3, abundance, %); Lee & McAlice, 1979 (p.228, annual cycle); Lonsdale & al., 1979 (p.235, carnivorous behavior); McAlice, 1981 (p.267, post-glacial history); Grice & Marcus, 1981 (p.125, Dormant eggs, Rem.: p.130, 135, 136); Cahoon, 1981 (p.1215, reproductive rate vs. food quality); Arashkevich & al., 1982 (p.477, Table 2, diet); Citarella, 1982 (p.791, 798: listing, frequency, fig.5, Tableau II, V); Turner & Dagg, 1983 (p.16); Landry, 1983 (p.614, development times vs. stages); Durbin & al., 1983 (p.1199, size-weight, Chl a, egg production); ); Roman, 1984 (p.949, feeding); Stearns & Forward, 1984 (p.85, photosensiivity); 1984 a (p.91, photobehavior); Turner, 1984 b (p.265, Table 1, fig.3-7: pellet contents); Dussart, 1984 (p. 25, 62:,occurrence); Tremblay & Anderson, 1984 (p.3); Peterson, 1985 (p.726, fig.2, abundance); Donaghay, 1985 (p.235, food quality, egg production); Stoecker & Sanders, 1985 (p.85, grazing); Tester, 1985 (p.45, egg-hatching); Baars & Oosterhuis, 1985 (p.71, Table 4: gut passage time); Kiørboe & al., 1985 (p.85, metabolism, egg production, respiration); Ambler, 1985 (p.743, egg production); 1986 (p.183, egg production); Stearns, 1986 (p.65, grazing behavior); Sullivan & McManus, 1986 (p.121, resting egg production); Beckman & Peterson, 1986 (p.917, egg production); Buskey & al., 1986 (p.65, behavior); Stoecker & Egloff, 1987 (p.53, feeding); Stearns & al., 1987 (p.305, grazing); Houde & Roman, 1987 (p.229, ingestion vs food quality); Libourel Kiørboe & Tiselius, 1987 (p.525, gut clearance); Johansen & Møhlenberg, 1987 (p.137, toxicity/egg production); Peterson W.T. & Bellantoni, 1987 (p.411, Table I, figs.7 egg production vs total chlorophyll concentration); Bellantoni & Peterson, 1987 (p.199, egg production); Jimenez-Perez & Lara-Lara, 1988 (p.122); Kleppel & al., 1988 (p.185, gut contents); Paffenhöfer & Stearns, 1988 (p.33, clearance rate); Dagg, 1988 (p.167, egg production vs. physical event); Donaghay, 1988 (p.469, acclimatation vs. food quality & trophic dominance); Berggreen & al., 1988 (p.341, feeding, production); Daan & al., 1988 (p.45, Table 4, carnivorous behaviour); Turner & Tester, 1989 (p.21, grazing); Tester & Turner, 1989 (p.231, feeding rate); Verity & Smayda, 1989 (p.161, ingestion-egg production); White & Dagg, 1989 (p.315, egg production vs. suspended sediment); Citarella, 1989 (p.123, abundance); Stearns & al., 1989 (p.7, egg production); Cervantes-Duarte & Hernandez-Trujillo, 1989 (tab.3); Sabatini, 1989 (p.847, annual cycle); Marcus, 1990 (p.413, tab.1, fig.2: egg); Støttrup & Jensen, 1990 (p.87, feeding, egg production); Tester & Turner, 1990 (p.169, Fig.4); Stoecker & McDowell Capuzzo, 1990 (p.891, feeding); Jonsson & Tiselius, 1990 (p.35, feeding behaviour, prey detection); Durbin & al., 1990 (p.23, diel feeding behavior); Mallin, 1991 (p.481); Haigh & Taylor, 1991 (p.301, Rem.: p.309); Fransz & al., 1991 (p.10); Gifford, 1991 (p.8, Table 2, diet); Gifford & Dagg, 1991 (p.161, feeding); Fernandez Araoz, 1991 (p.575); Tester & Turner, 1991 (p.603); Lee B.-G & Fisher, 1992 (p.117, fecal pellets); Huntley & Lopez, 1992 (p.201, Table 1, A1, B1, eggs, egg-adult weight, temperature-dependent production, growth rate); Hirche, 1992 (p.395, Table 1, egg production, r-strategy); Durbin & al., 1992 (p.342, Table 5, size-weight, egg production); White & Roman, 1992 (p.239, egg production); Kleppel, 1992 (p.57, feeding); Arfi & al., 1992 (p.213, filtration rate); Kimmerer, 1993 (tab.2); Roman & al., 1993 (p.1603, Oxygen effect); Saiz & al., 1993 (p.280, predation effect); Cervetto & al., 1993 (p.1207, feeding, respiration, egg production); Snell & Carmona, 1994 (p.255); Marcus & Lutz, 1994 (p.83, hatching success vs anoxia); Lutz & al., 1994 (p.119, hatching/O2 effect); Jonasdottir, 1994 (p.67, nutrition vs reproduction); Belmonte & al., 1994 (p.9); Miller & Marcus, 1994 (p.235, sinking velocity eggs); Wieser, 1994 (p.1, Rem.: p.18, fig.4A); Hoffmeyer, 1994 (p.303); Suarez Morales, 1994 b (tab.1); Butler & Dam, 1994 (p.81, production rates fecal pellets); Saiz & Kiørboe, 1995 (p;147, feeding modes and turbulence effect); de Angelis & Lee, 1994 (p.1298, methane production); Hajderi, 1995 (p.542); Santos & Ramirez, 1995 (p.133, Tabl. I, fig.2, 3); Marcus, 1996 (p.143); Hansen B. & Bech, 1996 (p.257, bacteria associated); Hansen B. & al., 1996 (p.275, degradation fecal pellets); Diaz Zaballa & Gaudy, 1996 (p.1123, seasonal variations); Kiørboe & al., 1996 (p.65, feeding: prey switching behaviour); Tiselius & Jonsson, 1997 (p.164, predation); Marcus & al., 1997 (p.291, hatching success vs anoxia); Mauchline, 1998 (tab.15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 33, 35, 36, 38, 40, 45, 46, 47, 48, 51, 53, 54, 56, 58, 62, 63, 64, 66, 68, 69, 78, fig.66); Lopes & al., 1998 (p.195); Alvarez-Cadena & al., 1998 (tab.2, 3); Hopcroft & al., 1998 (tab.2); Feinberg & Dam, 1998 (p.87, fecal pellets vs diet); Suarez-Morales & Gasca, 1998 a. (p107); Lavaniegos & Gonzalez-Navarro, 1999 (p.239, Appx.1); Gomez-Gutiérrez & Peterson, 1999 (p.637, Table II, abundance); Cervetto & al., 1999 (p.33); Onishchik, 1999 (p.76); Harvey & al., 1999 (p.1, 49: Appendix 5, in ballast water vessel); Støttrup & al., 1999 (p.257, development, lipids); Escribano & Hidalgo, 2000 (p.283, tab.2); Gaudy & al., 2000 (p.51, metabolism, temperature & salinity effects); Camatti & al., 2000 (p.41); Alvarez-Silva & Gomez-Aguirre, 2000 (p.163: tab.2); Gubanova, 2000 (p.105, introduction); Tester & al., 2000 (p.418, toxicity); Hidalgo & Escribano, 2001 (p.159, tab.2); Hidalgo & Escribano, 2001 (p.157, fig.4); Fransz & Gonzalez, 2001 (p.255, tab.1); Belmonte & Potenza, 2001 (p.174, 175: Rem.); Ara, 2001 b (p.121); Peterson & al. (p.381, Table 2, interannual abundance); Bressan & Moro, 2002 (tab.2); Uysal & al., 2002 (p.17, tab.1); Viñas & al., 2002 (p.1031); Besiktepe & Dam, 2002 (p.151, ingestion & defecation vs diet); Thor & al., 2002 (p.296, diet vs carbon incorporation); Dunbar & Webber, 2003 (tab.1); Zagorodnyaya & al., 2003 (p.52); Gubanova, 2003 (p.94, 99); Peterson & Keister, 2003 (p.2499, interannual variability); Vieira & al., 2003 (p.S163, Table 2, abundance); Titelman & Kiørboe, 2003 a (p.137, nauplius behaviour); Krumme & Liang, 2004 (p.407, tab.1); Ara, 2004 (p.179, figs. 3, 4, 5); Marrari & al., 2004 (p.667, tab.1); Vargas & Gonzalez, 2004 (p.151); Gaudy & Verriopoulos, 2004 (p.219): Invidia & al., 2004 (p.187, egg vs anoxia and sulfide); Gubanova, 2005 (p.146); Alvarez-Silva & al., 2005 (p.39); Choi & al., 2005 (p.710: Tab.III); David & al., 2005 (p.171); Berasategui & al., 2005 (p.485, tab.1); Manning & Bucklin, 2005 (p.233, Table 1); Bagøien & Kiorboe, 2005 a (p.129, mating); Holste & Peck, 2005 (p.1061, egg production , hatching success vs temperature & salinity); Azeiteiro & al., 2005 (p.7, fig.2, table 2, dynamic, production); Berasategui & al., 2006 (p.485: fig.2); Marques & al., 2006 (p.297, tab.III) ; Lopez-Ibarra & Palomares-Garcia, 2006 (p.63, Tabl. 1, seasonal abundance vs El-Niño, Rem.): p.74; Roman & al., 2006 (p.435, nutrition); Sterza & Fernades, 2006 (p.95, Table 1, occurrence); Sei & al., 2006 (p.121, feeding , eggs viabiliity vs oxygenation); Escribano, 2006 (p.20, Table 1); Hooff & Peterson 2006 (p.2610); Nielsen P. & al., 2006 (p.171, hatching success vs anoxia); Papastephanou & al., 2006 (p.3078, Table 3); Selifonova, 2006 (p.117); Drillet & al., 2006 (p.714, egg storage); Holste & Peck, 2006 (p.1061, egg production vs temperature & salinity); Sørensen & al., 2007 (p.84, Rem.: eggs); David & al., 2007 (p.59: tab.2); Woodson & al., 2007 (p.163: Rem; behavior); Speekmann & al., 2007 (p.759); Pedroso & al., 2007 (p.173, silver toxicity); S.C. Marques & al., 2007 (p.213, Table 1, fig.6); Chojnacki & al., 2007 (p.45, Table 2); Biancalana & al., 2007 (p.83, Tab.2, 3); Sullivan & al., 2007 (p.259, Rem.: climate change); Leandro & al., 2007 (p.215); Pinho & al., 2007 (p.62); Youn & Choi, 2007 (p.222: Table1, egg production); Castro & al., 2007 (p.486, fig.3, Table 1, 2, 3); Morales C.E. & al., 2007 (p.452, Rem.: p.462: abundance); David & al., 2007 a (p.429, figs.2, 4, 5, 6, Table 3, 4, 5, 6); Marques S.C. & al., 2007 (p.725, Table 1, fig.4, climate variability); Titelman & al., 2007 (p.1023, Table I, Rem: mating); Drillet & al., 2008 (p.109, genetic analysis, eggs); Sullivan & al., 2008 (p.485); Chen & Hare, 2008 (p.1451, molecular biology, cryptic ecological diversification); Smith J.R. & al., 2008 (p.937, Rem.: feeding behavior); Ayon & al., 2008 (p.238, Table 4: Peruvian samples); Peck & al., 2008 (p.102, egg production); Shmeleva & al., 2008 (p.31, Table 1); Waggett & Buskey, 2008 (p.111, Table 1); Muelbert & al., 2008 (p.1662, Table 1); Calliari & al., 2008 (p.18, salinity effecs); Hubareva & al., 2008 (p.131, Table 1, 2); Saco-Alvarez & al., 2008 (p.275, Table 1, toxicity from fuel tanker); Drillet & al., 2008 (p.47, rearing); Tiselius & al., 2008 (p.93, reproduction, biomass, mortality); Larsen & al., 2008 (p.47, fig.1, Table 1, swimming-temperature-viscosity); Galbraith, 2009 (pers. comm.); Calliari & al., 2009 (p.1045, grazing, egg production rates); Brylinski, 2009 (p.253: Tab.1, p.256: Rem.); Ohs & al., 2009 (p.114, Rem.: eggs); Tartarotti & Torres, 2009 (p.106, UV effects); Kozlowsky-Suzuki & al., 2009 (p.395, Table 2, nutrition, oocyte development); Aravena & al., 2009 (p.621, seasonal & spatial distribution vs environmental factors); Telesh & al., 2009 (p.18: Table 2.1); Magalhaes & al., 2009 (p.187, Table 1, %); Escribano & al., 2009 (p.1083, Table 1, figs.6, 10); Primo & al., 2009 (p.341, Table1, interannual variations); Elliott & Tang, 2009 (p.585, dead/live vs staining); Hansen B.W. & al., 2010 (p.305 (egg hatching); C.E. Morales & al., 2010 (p.158, Table 1); Escribano & Pérez, 2010 (p.301, Fig.4: fatty acids); Hernandez-Trujillo & al., 2010 (p.913, Table 2); Hidalgo & al., 2010 (p.2089, fig.2, 4, Table 2, cluster analysis); Zenetos & al., 2010 (p.397); Yen & Lasley, 2010 (p.177, Rem.: p.183, mating): Mazzocchi & Di Capua, 2010 (p.423); Thor & Wendt, 2010 (p.1779, Carbon absorption); Medellin-Mora & Navas S., 2010 (p.265, Tab. 2); S.C. Marques & al., 2011 (p.59, Table 1, seasonal variability); Hogfors & al., 2011 (p.1460, fig.1, egg production); Acheampong & al., 2011 (p.151, egg production vs biochemical food), Rem: p.157, resting egg; Bollens & al., 2011 (p.1358, Table III); Kusk & al., 2011 (p.959, development vs environment & polluant); Magalhaes & al., 2011 (p.1520, seasonal abundance); Magris & al., 2011 (p.260, abundance, interannual variability); Escamilla & al., 2011 (p.379, spatial & seasonal abundance, competition); Costa R.G. da & al., 2011 (p.364, Table 1, seasonal occurrence); Tutasi & al., 2011 (p.791, Table 2, abundance distribution vs La Niña event); Scheef & Marcus, 2011 (p.363, resting eggs); Buskey & al., 2011 (p.57, fig.3, sensory perception vs predator); Gemmell & Buskey, 2011 (p.1773, nauplii/copepodites vs fish predation); Turner & al., 2011 (p.1066, Table II, abundance 1998-2008); Drillet & al., 2011 (p.831, feeding vs microbial preparation); Menéndez & al., 2011 (p.281, tidal effect); Ramos Avila & al., 2011 (p.323, chitobiase enzyme activity); Elliot & Tang, 2011 (p.1039, spatial & temporal distribution); 2011 a (p.1, population dynamics, mortality rate); Jiang & al., 2011 (p.947, resistance vs dinoflagellate); Saba & al., 2011 (p.291, harmful algal vs grazing); Bickel & al., 2011 (p.105, mortality vs turbulence); Amin & al., 2011 (p. 1965, clearance, feeding, egg production vs diets); Chen X. & al., 2011 (p.451, C N Fe concentration vs diet, egg production); Chen X. & al., 2011 (p.716, fatty acid vs diet); Alver & al., 2011 (p.100, nauplius stages); Saba & al., 2011 (p.47, excretion); Sichlau & al., 2011 (p.665, diapause eggs in sediments); Costa K.G. da & al., 2011 (p 356, , fig. 2: phylogenetic tree, genetic divergence); Postel, 2012 (p.327, Table 1, Fig.6); Delpy & al., 2012 (p.1921, Table 2); Hansen B.W & al., 2012 (p.613, eggs/salinity); Stefanova & al., 2012 (p.403, Table 2, interannual abundance); Olivotto & al., 2012 (p.685, egg production, molecular analysis); Guenther & al., 2012 (p.405, 411); Menéndez & al., 2012 (p.11, variability vs physical processes); Borg & al., 2012 (p.1, Nauplii swimming); Bruno & al., 2012 (p.1, Nauplii behaviour); Gorbi & al., 2012 (p.2023, test of toxicity vs eggs, nauplii); Malzahn & Boersma, 2012 (p.1408, feeding vs growth); Hong J. & al., 2012 (p.1, feeding behavior vs algal toxins); Drillet & al., 2012 (p.155, Table 1, culture); Kimmel & al., 2012 (p.76, long-term abundance record vs eutrophication); Muxagata & al., 2012 (p.475, Table 3, growth, annual production); Gonçalves & al., 2012 (p.321, abundance vs climatic variability); Menéndez & al., 2012 (p.389, Table 1: seasonal abundance); Spinelli & al., 2012 (p.39, potential prey for fish); Gonçalves & al., 2012 a (p.16, abundance, diel vertical behavior); Lavaniegos & al., 2012 (p. 11, Table 1, fig.3, seasonal abundance, Appendix); Buskey & al., 2012 (p.57, Fig.1, 3, behavior vs predator); Miyashita & al., 2012 (p.1557, Table 2: occurrence); Oechsler-Christensen & al., 2012 (p.161, grazing vs phytoplankton pigments); Aguirre & al., 2012 (p.341, Table I: abundance vs season, figs.4, 7); Durbin & al., 2012 (p.72, feeding & digestion rates); Hidalgo & al., 2012 (p.134, Table 2, 3, figs.5, 6, spatial distribution vs hydrology); Takahashi M. & al., 2012 (p.393, Table 2, water type index); Gusmao & al., 2013 (p.279, Table 4, sex ratio); Gubanova & al., 2013 (in press, Rem.: p.5, Table 4, fig.2, alien species); Palomares-Garcia & al., 2013 (p.1009, Table I, abundance vs environmental factors); in CalCOFI regional list (MDO, Nov. 2013; M. Ohman, pers. comm.); Gissi & al., 2013 (p.86, Table 3, copper toxicity); Chaalali & al., 2013 (p.1, abundance change vs. environmental conditions during the period 1992-2010); Elliott & al., 2013 (p.1027, low-oxygen effects); Elliott & al., 2013 a (p.1, hypoxia effects); Finiguerra & al., 2013 (p.17, sex tolerance vs. starvation); Garbosa da Costa & al., 2013 (p.756, Table 1, abundance vs tide); Zhang J. & al., 2013 (p.65, diets vs egg production, hatching success); Heuschele & al., 2013 (p.399, Table 2, mate behavior); Jarvis & al., 2013 (p.1264, Zinc oxide effects vs survival, production); Peijnenburg & Goetze, 2013 (p.2765, genetic data); Hansen B.W. & Drillet, 2013 (p.66, oxygen consumption, subitaneous and delayed hatching eggs); Fernandez-Severini & al., 2013 (p.1495, heavy metals concentrations); Alvarez-Silva & Torres-Alvarado, 2013 (p.241, Table1: seasonal abundance); Dunlap & al., 2013 (p.1375, mortality vs viral infestion); Mendoza Portillo, 2013 (p.37: Fig.7, seasonal dominance); Lidvanov & al., 2013 (p.290, Table 2, % composition); Pansera & al., 2014 (p.221, Table 2, abundance); Rice & al., 2014 (p.23, fig.3, size vs years 1952-2011); Pino-Pinuer & al., 2014 (p.83, Table 1, fig.3, 4, abundance variation vs time); Fierro Gonzalvez, 2014 (p.1, Tab. 3, 5, occurrence, abundance); Ortega & al., 2014 (p.495, Table I); Hylander & al., 2014 (p.149, figs. 2, 3, Table 2; life history vs UV exposure); Ruz & al., 2015 (p.200, seasonal abundance vs egg production, hatching success vs O2); Fuentes-Reinés & Suarez-Morales, 2015 (p.369, Table 1, Rem. p.373); Meunier & al., 2016 (p.50, selective feeding vs N/P contents for nauplii, copepodite); Uriarte & al., 2016 (p.718, abundance vs years, climate change); Escribano & al., 2016 (p.1, growth rate); Araujo & al., 2016 (p.1, Table 3, abundance, %); Ben Ltaief & al., 2017 (p.1, Table III, Summer relative abundance); Ortega & al., 2017 (p.123, fig. 1, 5, 6, table 2, abundance, %) ; Trottet & al., 2017 (p. 7, Table 3: resting stage); Marques-Rojas & Zoppi de Roa, 2017 (p.495, Table 1); Jerez-Guerrero & al., 2017 (p.1046, Table 1: temporal occurrence); Buskey & al., 2017 (p.754, amyelinate fiber vs escape response) .
NZ: 16

Distribution map of Acartia (Acanthacartia) tonsa by geographical zones
Species Acartia (Acanthacartia) tonsa - Distribution map 4
Chart of 1996
Species Acartia (Acanthacartia) tonsa - Distribution map 5issued from : P. Remy in Annales de Biologie Lacustre, 1926 (1927 a), XV. [p.179]: geographic distribution in 1926.
1 : Port-Jackson (Australia) catches by Dana in 1840. 2 to 7: Pacific coast from South America (Valparaiso to Coquimbo and Arica, Chile; Mollendo and Callao, Peru) by Giesbrecht (1892). 8 and 9: Pacific coast from North America (San Diego region) by Esterly, 1905, 1923. 10: Bay of San Francisco by Esterly, 1924. 11: Sub-Antarct (Falkland Is.) by T. Scott, 1914. 12: Northwestern Atlantic (Mouth of Orenoque) by Cleve, 1900. 13, coast of Louisiane by Foster, 1904; 14-18:: Jamaica Bay near New York and along the coast until the bay of Fundy, by Sharpe (1910), Wheeler (1900), Williams (1906, 1907), Steuer (1923). 19-20: In the Indian Ocean (Mouth of Indus by Cleve, 1904; Maldive islands by Wolfenden, 1905. In Sunda Islands by, Cleve, 1901. In France (Channel of Caen-Ouistreham harbour)
Species Acartia (Acanthacartia) tonsa - Distribution map 6issued from : J.M. Brylinski in J. Plankton Res., 1981, 3 (2). [p.256, Fig.1].
Geographical distribution of Acartia tonsa in northern European waters.
Species Acartia (Acanthacartia) tonsa - Distribution map 7issued from : M.E. Sabatini in Scient. Mar., 1989, 53 (4). [p.855, Tabl.2].
Seasonal occurrence, number and duration of Acartia tonsa generations in different areas.
Locality; Latitude; temperature range (°C) ; seasonal occurrence; number of generations (cohorts); generation time (in weeks); author reference.
Species Acartia (Acanthacartia) tonsa - Distribution map 8issued from : G.B. Deevey in Bull. Bingham Oceanogr. Coll., 1960 (2). [p.27, Fig.14].
Variations in length (from the top of the head to the base of the caudal rami) of Acartia tonsa females and males in the Delaware Bay (NW Atlantic Ocean).
Species Acartia (Acanthacartia) tonsa - Distribution map 9issued from : J.T. Turner in P. S. Z. N. I: Mar. Ecol., 1984, 5 (3). [p.273, Fig.5].
Contents of fecal pellets from Acartia tonsa females from Station A-2 (off Mississipi Eiver mouth) on 9 December 1981.
a and b: small unidentified centric diatom (arrow); c: fragments of Skeletonema costatum (S) and an uniddentified centric diatom (UC); d: fragments of an unidentified diatom; e: Chaetoceros sp. spine (C) and fragments of a crustacean exoskeleton (CE), note dagger-like spines which appear to be chemoreceptors; f: crustacean appendages (CA) underneath the pellet peritrophic membrane (PM).
Species Acartia (Acanthacartia) tonsa - Distribution map 10issued from : M.R. Reeve in Bull. mar. Sc., 1970, 20 (4). [p.902, Fig.4].
Temperature-salinity diagram for Acartia tonsa in Biscayne Bay (Florida, Miami).
Species Acartia (Acanthacartia) tonsa - Distribution map 11issued from : B. Hansen, F.L. Fotel, N.J. Jensen & S.D. Madsen in J. Plankton Res., 1996, 18 (2). [p.284, Fig.6, p.285, Fig.6 continued].
Video prints of the degradation of fecal pellets incubated in 0.22 micrometer filtered seawater as a function of time. The fecal pellets were produced on the nanoflagellate Rhodomonas baltica at excess food by the copepod Acartia tonsa.
The light intensity and video camera shutter speed were kept equal at all readings to make direct comparison possible. Scale bar = 0.100 mm.

Nota: Degradation of freshly produced fecal pellets in suspension was followed over time by volume recording and estimation of carbon loss.
The fecal pellets produced on a diatom diet were very dense and showed a significantly slower degradation than those produced on nanoflagellate or dinoflagellate diets. This indicates that the algal texture (i.e. the mechanical robustness given by inert structures) determines the degradation rate of the pellets.
The degradation rate was also very dependent on the algal concentration for the grazer (565 microgg. C per day T 1/2 = 75 h; excess food T 1/2 = 12 h).
Disintegration and degradation are processes of bacterial activity and mechanical stress in combination while the fecal pellets are in a suspension with no predators (see Jacobsen & Azam, 1984). Fecal pellets, in situ, however, are presumably exposed to coprophagy and coprorhexy from mesozooplankton (see Noji & al., 1991). The authors found a faster degradation while ciliates (Euplotes sp.) were accidentally contaminants in an incubation vial.
Free-living bacteria colonized the fecal pellets. After initiating colonization, the bacteria penetrated the peritrophic membrane, wich clearly leaked out material, observed as fecal pellets losing color (fig.6). Then the bacteria began the degradation of the fecal pellet matrix (Noji & al., 1991; Gonzalez, 1992). This scenario was already suggested by Gowing & Silver (1983) and Dellile & Razouls (1994) who stated that fecal pellets generally contain abundant internal bacteria.
During the degradation of the diatom-based pellets, the authors frequently observed coprochaly, where the matrix of the pellets swells, with the content of labile carbon disappearing. This was, however, never observed in the present nanoflagellate and dinoflagellate experiments.
Corner & O'Hara (1986, p.303) underline that after Sochard & al. (1979) studying microorganisms in Acartia tonsa found a unique gut flora dominated by numerous species of the genus Vibrio, and Gowing & Silver (1983) found that the mean volumes of bacteria inside such pellets were greater than those on their surface, a condition still prevailing after these pellets had been aged for over five days in sea water. Honjo & Roman (1978) could detect no bacteria in the faecal pellets released by copepods fed on bacteria-free diets.
Species Acartia (Acanthacartia) tonsa - Distribution map 12issued from : M.M. Mullin & P.M. Evans in Limnol. Oceanogr., 1974, 19 (6). [p.907, Fig.2].
Biomasses (bodily carbon) of various components integrated over the water column in the deep tank (cylinder 10 m deep and 3 m in diameter, about 70 m3 of sea water [from the Scripps Institution, La Jolla, San Diego], fiiltered through fine diatomaceous earth; to darken during the experiment.
Arrows on the ababsissa indicate the start and end phases of the experiment. The dashed line under ''copepods'' indicates the biomasses of Acartia tonsa and Paracalanus parvus during the transition period.

Nota: Establishment of a linear food chain consisting of the chain-forming diatom Skeletonema costatum, the copepods A. tonsa and P. parvus (particle-grazing), and ultimately the ctenophore Pleurobrachia bachei (coastal carnivore).
The experiment was divided into three phases; during the first two phases only copepods were present, A. tonsa initially dominating but subsequently being replaced by P. parvus (phase II). Phase III was that portion of the experiment when ctenophores were present together with P. parvus.
Assuming that the C:Chl ratio was maintened in the deep tank, the contribution of phytoplankton to the total particulate carbon (fig.2) can be calculated. The median level of the remaining, presumably detrital, particulate carbon was 140 mg/m3 (similar to the concentration of detritus in the near surface waters off La Jolla).
During phase I, when Acartia was dominant, the biomass of copepods fluctuated considerably and then declined until Paracalanus became dominant, thus starting phase II. It appear that Paracalanus has a higher rate of turnover than does Acartia but uses its food supply less effectively, resulting in a slightly lower food chain efficiency.
The median biomass of ctenophores in the tank was 16% that of the copepods during phase III (fig.2) and the biomass of copepods was similar to the local biomass of prey species for Pleurobrachia in spring, summer and fall (see Hirota, 1974: Table 10).
The field study of a marine planktonic food chain with which the experiment's results can be most directly compared is that of Petipa & al. (1970) in the Black Sea.
Species Acartia (Acanthacartia) tonsa - Distribution map 13Issued from : R.J. Conover in Bull. Bingham Oceanogr. Coll., 1956, XV. [p.181, Fig.13].
Size distribution of adult females Acartia tonsa from Long Island Sound ( U.S.A.) at different times of the year, 1952-1953.
Species Acartia (Acanthacartia) tonsa - Distribution map 14Issued from : R.J. Conover in Bull. Bingham Oceanogr. Coll., 1956, XV. [p.176, Fig.11, C].
Seasonal distribution in percent of total organisms of adults and naupliiAcartia tonsa from Long Island Sound, U.S.A.) 1952-1953.
The number of generations was estimated from the distribution of nauplii and adults.
The nauplii of each generation are designated by Roman numerals and the corresponding adults in Arabic;

Nota: There were probably 4 generations annually in the Sound, produced in the period from June through March. The development ofhe first two generations is clear enough; however, on September 23, a secondary peak of adults appeared which must have produced some of nauplii III. After mid-October, the percentage of A. tonsa in the tows increased while totals of all species were decreasing, suggesting that tonsa was more resistant to fall and winter conditions than other summer zooplankton forms..
In any event, adult peak 3 appears to be significant. The designation IV applies to low levels of nauplii produced through the cooler months. Possibly a few of the early IV nauplii matured so as to produce an overwintering population which consisted of both adults 3 and 4
Species Acartia (Acanthacartia) tonsa - Distribution map 15Issued from : E.J. Buskey, P.H. Lenz & Hartline D.K. in Adaptative Behavior, 2012, 20 (1). [p.62, Fig.3];
Comparison of capture success of the copepod Acartia tonsa by a predator mimic (siphon) and a fish predator, the coral reef blenny Acanthemblemaria spinosa at three different water speeds in a unidirectional paddle flume, or a slosh flume that simulates the oscillatory flow of surface waves.
Error bars represent standard error.
Data from Robinson & al., 2007 and Clarke & al., 2009

Nota: Althrough the maximum water speeds in the two fumes were similar, the reversing flow in the slosh flume produced much higher levels of turbulence compared with the continuous flow in the paddle flume. The different patterns of capture success (the proportion of copepods captured by the siphon or fish compared with the number of copepods encountered) demonstrated by the siphon and the fish, clarified the separate effects of water motion on the predator and its prey.
For both flume types, the capture success of the siphon increased with increasing flow speeds. However, capture success with the siphon was consistently higher in the slosh flume than in the paddle flume at comparable speeds, suggesting that the copepod had more difficulty recognizing the flow signal associated with the siphon in the more turbulent flows of the slosh flume.
When the disturbances are detected, copepods respond quickly with escape jumps that can accelerate them from a stationary position to speeds of over 600 body lengths per second within a few milliseconds. Myelinated nerves may improve the escape behavior of some copepods through faster conduction of nerve impulses. The differences in response latencies between myelinate and amyelinate copepod species are greatest in larger copepod species, where nerve signals must be conducted over longer distances.
Small amounts of turbulence favor the predator, while too much turbulence reduces predation.
Species Acartia (Acanthacartia) tonsa - Distribution map 16Peterson W.T. & Bellantoni, 1987 (p.415, fig.6].
Fecundity of Acartia tonsa and Temora longicornis in Long Island Sound (USA).
Species Acartia (Acanthacartia) tonsa - Distribution map 17Peterson W.T. & Bellantoni, 1987 (p.416, Fig.7, c, d].
Scattergramms of egg production against chlorophyll concentration for Acartia tonsa in Long Island Sound.
The rates obtained with in situ temperatures > 17°C. Data from 30 October and 7 and 20 November shown in figure 6 are not included because low temperatures rather than food concentration probably limited fecundity on those days.
Species Acartia (Acanthacartia) tonsa - Distribution map 18Issued from : T. Kiørboe, E. Saiz & M. Viitasalo in Mar. Ecol. Prog. Ser., 1996, 143. [p.68, Fig.1].
Acartia tonsa. Calm water functional response to variations in the concentration of diatoms: (A) ingestion and (B) clearance. (o) Diatoms Thalassiosira weissflogii only; (black o) T. weissflogii and ciliate Strombidium sulcatum added at a concentration of 12 ml per l. Error bars show ± SD.

Nota: The copepod Acartia tonsa has 2 different prey encounter stategies. It can generate a feeding current to encounter and capture immobile prey (suspension feeding) or it can sink slowly and perceive motile prey by means of mechanoreceptors on the antennae (ambush feeding). It is hypethesized taht A. tonsa adopts the feeding mode that generates the highest energy intake rate; i.e. that prey selection changes according to the relative concentration of alternative prey (prey switching) and that the copepod spend disproportionately more time in the feeding mode that provides the greatest reward. based on earlier observations , it is hypothesized that turbulencnce changes food selection towards motile prey.
Species Acartia (Acanthacartia) tonsa - Distribution map 19Issued from : X. Chen, S.B. Baines & N.S. Fisher in Limnol Oceanogr., 2011, 56 (2). [p.455, Fig.2].
Egg production rates of Acartia tonsa feeding on Fe-replete (filled symbols) and Fe-depleted (open symbols) cells of (A) Thalassiosira oceanica, (B) Rhodomonas salina, (Diatoms), and (C) Isochrysis galbana (Prymnesiophyte), over a 5-d period.
Data points are means of 3 replicates ± 1 SD.

Nota: Egg production was always lower for copepods fed an Fe-depleted diet, regardless of the algal species that was used as food. When T. oceanica was used as a food source, the rate of egg production decreased significantly over 5-d feeding period in the low-Fe treatment, but in all other cases egg production dir not vary systematically over the course of the experiment.
After 5-d of feeding on T. oceanica, copepods produced eggs at a rate of 7.4 eggs per individual per day under Fe-replete conditions, and 0.6 eggs per ind. per day in the Fe-depleted treatment after 5 days of feeding..
When fed on Fe-replete R. salina and I. galbana the egg production rate after 5 days of feeding was 15.4 eggs per ind. per day and 8.5 eggs per ind. per day, respectively, while Fe-depleted R. salina and I. galbana diets at the same time resulted in egg production rates of 10.4 eggs per ind. per day and 6.2 eggs per ind. per day, respectively.
As noted by several authors, iron (Fe) is a limiting nutrient for phytoplankton growth in over 30 % of the world's oceans, including the Equatorial Pacific Ocean, the Southern Ocean, the Subarctic Pacific, and some coastal areas (see Martin & al., 1991; Hutchins & Bruland, 1998; Hutchins & al., 2002). Fe-deficient phytoplankton cells have lower nitrogen (N), phosphorus (P) and sulfur concentrations and higher silicon (Si) (Twining & al., 2004).
Species Acartia (Acanthacartia) tonsa - Distribution map 20Issued from : X. Chen, S.B. Baines & N.S. Fisher in Limnol Oceanogr., 2011, 56 (2). [p.456, Fig.3].
Naupliar survival of Acartia tonsa feeding on Fe-replete or Fe-depleted Thalassiosira oceanica (Diatom).
(A) Time series of number of surviving individuals for the Fe-depleted (open circles) and Fe-replete (filled circles) treatments. The lines represent best-fit regressions of the form Nt = 100 e -mt, where Nt is the number of individuals alive at time t, and m is the instantaneous mortality rate. The last two points for the Fe-depleted treatment (open circles with crosses) were not used to fit the lines because of elevated mortality rates during these periods.
(B) Time series of mortality rate for the Fe-depleted (open bars) and Fe-replete (filled rates). Mortality calculated as the fraction of individuals that died durung that interval divided by the number alive at the start of the interval.

Nota: All nauplii in the Fe-depleted treatment died within 1 week after hatching, whereas 60 % of the nauplii fed on Fe-replete diatoms survived during this period.
The daily mortality rate of nauplii fed on Fe-depleted T. oceanica was higner than for nauplii fed Fe-replete food for every 1-d interval during the experiment. Average instantaneous mortality estimatd by regression was 30 % ± 4 % per day when nauplii were fed Fe-depleted food and 8 % ± 0.4 % per day when fed Fe-replete food.
Carbon ingestion rates of algae ranged between 1.31 µg C per ind. per day and 3.01 µg C per ind. per day under all food conditions during the 5-d feeding period.. C ingestion rates were not affected by Fe status of algal food for any algal species. C ingestion rates of copepods ingesting T. oceanica were significantly higher than those feeding on R. salina and I. galbana, but no significant difference was observed between R. salina and I. galbana treatments.
Species Acartia (Acanthacartia) tonsa - Distribution map 21Issued from : X. Chen, S.B. Baines & N.S. Fisher in Limnol Oceanogr., 2011, 56 (2). [p.457, Table 2].
Rates of Fe and C assimilation in copepods A. tonsa (µmol per ind. per day, µmol per ind. per day, respectively) fed on three species of algae. Values shown are means from 3 reolicate cultures ± 1 SD.

Nota: The rates of Fe and C assimilation in copepods fed on Fe-replete and Fe-depleted algal cells show that C assimilation was unaffected by the Fe content of the diet, but Fe assimilation was significantly greater (21-28 times) when copepods fed on Fe-replete cells than when fed Fe-depleted cells.
The Fe:C ratios in copepods that fed on Fe-replete cells (47.8 ± 7.9 (µmol per mol.) were not significantly different from Fe:C ratios in copepods that fed on Fe-depleted algae (54.8 ± 8.7 µmol per mol.)
Species Acartia (Acanthacartia) tonsa - Distribution map 22Issued from : X. Chen, S.G. Wakeham & N.S. Fisher in Limnol Oceanogr., 2011, 56 (2). [p.721, Table 6].
Fatty acic concentration in Acartia tonsa after feeding on thhree different algal species (mg per g C) that had been grown under Fe-deficient and Fe-replete conditions. Means of duplicate samples ± variance. nd: not detected.

Nota Laboratory experiments to determine the influence of iron on the fatty acid and sterol composition of the diatom Thalassiosira oceanica, the cryptothyte Rhodomonas salina, the prymnesiophyte Isochrysis galbana, and the copepod Acartia tonsa that fed on these algae
Algal cells were cultured with no added Fe or with Fe added at 100 nmol per L.
Fe-deficient culture medium resulted in lower growth rates, cell volumes, and photosynthetic efficiencies for all algal species.
The btotal mass of fatty acid per cell was 2.2-3.1 times as high in Fe-replete cells as in Fe-deficient cells; on a carbon-normalized basis, the fatty acid concentrations of Fe-replete algal cells were 1.4-1.5 times as high.
Differences were noted between Fe treatments for specific satured, nonsaturated, and poluunsaturated fatty acid within each algal species.
Differences in lipid concentration and composition between Fe-replete and Fe-deficient algae may partly explain the lower egg production rate of copepods fed Fe-deficient algae.
Species Acartia (Acanthacartia) tonsa - Distribution map 23Issued from : X. Chen, S.G. Wakeham & N.S. Fisher in Limnol Oceanogr., 2011, 56 (2). [p.721, Table 7].
Sterol concentrations in Acartia tonsa after feeding on three different algal species (mg per g C) that had been grown under Fe-deficient and Fe-replete conditions. Means of duplicate samples ± variance. nd: not detected.
Species Acartia (Acanthacartia) tonsa - Distribution map 24Issued from : A. Magalhaes, D.S.B. Nobre, R.S.C. Bessa, L.C.C. Pereira & R.M. da Costa in J. Coastal Res., 2011, SI 64. [p.1522, Fig.2].
Seasonal variation in the abundance, biomass and productivity of Acartia tonsain the Taperaçu estuary (00°55'06.8''S, 46°44'00''W) in July (rainy season) and October (dry season), 2004, during spring tides (flood and ebb periods), at 3-hour intervals over 24-hour period. with a plankton net (300 µm mesh aperture).
Species Acartia (Acanthacartia) tonsa - Distribution map 25Issued from : D.T. Elliot & K.W. Tang in Mar. Ecol. Prog. Ser., 2011, 427. [p.1].
Acartia tonsa (from lower Chesapeake Bay, USA) live (red color) and dead (brown color) after treatment with neutral red stain showing individuals (nauplii in top row, copepodites in bottom row).

Nota: Mortality is a poorly constrained parameter in population dynamics. Uncertainty in mortality rate stems from the inherent difficulties in measuring this process in situ (see Ohman & Wood, 1995). A posteriori adjustments of mortality rates are required to match model predictions to observations (see Runge & al., 2004), because mortality can affect the behavior of population dynamics models and nutrient-phytoplankton models (see Steele & Henderson, 1992).
Studies of population dynamics have often focused on predatory mortality, to the exclusion of non-predatory factors. Several studies have considered non-predatory mortaliy due to factors such as physiological state, diet and starvation (reviewed in Carlotti & al., 2000), as well as disease and parasitism (see Kimmerer & McKinnon, 1990), environmental stressors (see Carpenter & al., 1974) and ageing (see Rodriguez-Graña & al., 2010). There is no a priori reason to consider in non-predatory mortality of marine copepods as negligible. An analysis of longevity data from field and laboratory studies suggested that non-predatory factors account for 25 to 33 % of total mortality among adult copepods in the sea (see Hirst & Kiørboe, 2002)
Non-predatory mortality leaves behind a carcass that, in an estuary, may remain in the water column for several days (see Tang & al., 2006 ; Elliot & al., 2010) in the open ocean it may remain for months (see Terazaki & Wada, 1988). Failure to identify carcasses in samples could skew estimates of live copepod abundance and associated ecological parameters. For example, if one were to estimate copepod production from abundance data on a single day, assuming that all collected animals were alive, the true production would br surestimated by a factor of (1/Plive) exp. G, where Plive is the proportion actually alive on that day and g is the number of generations over which the forecast is made.
Consider the estuarine A. tonsa, which may have 9 generations in a year (Mauchline, 1998), multiple years of field sampling have demonstrated that from about 10 to 30 % of individuals in the lower Chesapeake Bay are carcasses (see Tang & al., 2006 ; Elliott & Tang, 2011). Assuming a relatively consevative value of 15 % dead A. tonsa (i.e 85 % alive and producing), annual production foresasted from abundance data taken during the first generation of the growing season would be overestimated by a factor of (1/0.85) exp.9 = 4.32 if carcasses were counted as live copepods.
Elliott & Tang (2011) described the abundance of live copepods and carasses in the lower Chesapeake Bay over 2yr. Cacasses were identified by neutral red vital staining. The authors found that copepod carcasses were prevalent throughout the study area, and that visibly injured carcasses were rare (< 2% of carcasses). The majority of these carcasses appeared to have resulted from non-predatory mortality.
Species Acartia (Acanthacartia) tonsa - Distribution map 26Issued from : D.T. Elliot & K.W. Tang in Mar. Ecol. Prog. Ser., 2011, 427. [p.4, Fig.1].Acartia tonsa Time series of (a) mean (diamonds) and range (bars) of water temperature, (b) mean temperature-specific population egg production rate predictions from equation of Holste & Peck, 2006 (Table 1), and (c) mean proportion observed in each developmental stage group (nauplii NI-NIII, NIV-NVI); copepodite CIV-CV; adult CVI) used to estimate mortality rates (copepodite CI-CIII not used). Means are from all samples within a specific tributary on a specific date.

Nota; After removing carcasses, instantaneous mortality rates for nauplii varied from <0.01 per day to a maximum of 0.35 per day and for copepodites from <0.01 per day in winter to 0.5 per day or higher in summer. Non-predatory mortality comprised an average of 25 % of total mortality for nauplii, and 12 % of total mortality for copepodites.. Predatory mortality alone was insufficient to keep yje population size under control during the growing season (from June to October), demonstrating the importance of non-predatory mortality in the lower Chesapeake Bay.
Total mortality rates varied in a cyclic manner annually, peaking in the summer. Corrected total mortality for nauplii varied from near 0.0 per day in the fall and spring to a maximum of 0.12 per day in June 2008 and 0.35 per day in August 2009.Corrected total mortality for copepodites was near 0.0 per day in the winter, and ca. 0.7 per day in summer 2008 and 0.9 per day in summer 2009, with a maximum of 1.52 per day in July 2009.
Corrected mortality rates were significantly different from uncorrected rates, both for nauplii and copepodites.
The difference was obvious for nauplii, where uncorrected mortality rates were consistently higher than corrected rates. Mortality rate estimates for copepodites were only slightly influenced by the inclusion of carcasses. This was due to the fact a similar percentage of carcasses was found in both CIV-CV and CVI copepodite stage groups, meaning that carcasses caused only a small bias in the abundance ratio that was used to estimate mortality by the vertical life table approach.
Water temperature predicted the vast majority of explained variation in mortality rates, being responsible for >98 % of each model R2 value. Water temperature varied cyclically during both years of study, with annual maxima near 28°C in July and August.
Predicted population egg production rate showed also an annual cycle, peaking in July through September, with lowest values in January of both years. Overall, estimated population egg production rates were consistently high (>1000 eggs per m3 per day) from April through October. The proportions of individuals in each developmental stage group were similar throughout most of the study period, except during winter when the relative abundance of adults increased markedly. Stage-duration-corrected abundancedeclined across consecutive stage groups during spring, summer, and fall,although only slightly between NI-NIII and NIV-NVI. Again, the exception was seen in winter samples when duration of NIV-NVI were higher than NI-NIII.
Species Acartia (Acanthacartia) tonsa - Distribution map 27Issued from : D.T. Elliot & K.W. Tang in Mar. Ecol. Prog. Ser., 2011, 427. [p.7, Fig.4].
Acartia tonsa (from Chesapeake lower Bay, USA). Regression analysis of temperature vs total copepod mortality rates.
VLT approach: vertical life Table approach. see in Aksnes & Ohman, 1996.
Species Acartia (Acanthacartia) tonsa - Distribution map 28Issued from : D.T. Elliot & K.W. Tang in Mar. Ecol. Prog. Ser., 2011, 427. [p.9, Fig.7].
Acartia tonsa (from Chesapeake lower Bay, USA). Regression analysis of temperature vs predatory and non-predatory mortality rates.
VLT approach: vertical life Table approach. see in Aksnes & Ohman, 1996.
Species Acartia (Acanthacartia) tonsa - Distribution map 29Issued from : D.T. Elliott & K.W. Tang in Limnol. & Oceangr.: Methods, 7, 2009. [p.589, Fig.2].
Appearance of neutral red-trated zooplankton under stereomicroscope (Nikon SMZ1000- and recommended lightling. Shown are 100 % dead and 100 % live Acartia tonsa (A), patchily stained and pink individuals (B), and the live and dead individuals of various developmental stages (C).
Species Acartia (Acanthacartia) tonsa - Distribution map 30Issued from : D.T. Elliott & K.W. Tang in Limnol. & Oceangr.: Methods, 7, 2009. [p.588, Table 2].
Comparison of preservation methods on the % stained Acartia tonsa.
Species Acartia (Acanthacartia) tonsa - Distribution map 31Issued from : D.T. Elliott & K.W. Tang in Limnol. & Oceangr.: Methods, 7, 2009. [p.587, Fig.1].
Diagram of the recommended protocol of the neutral red method for collection, staining, and live/dead sorting of zooplankton samples.
Species Acartia (Acanthacartia) tonsa - Distribution map 32Issued from : I. Uriarte, F. Villate & A. Iriarte in J. Plankton Res., 2016, 38 (3). [p.724].
Monthly time-series from 1998 to 2011 of Acartia tonsa (black) and Calanipeda aquaedulcis (grey) in the inner estuary of Bilbao (NW Spain). Thicker lines are moving averages. Ro is the Spearman's rank correlation coefficient (***P<0.001).

Nota: From 2003 to 2009, a replacement in the dominance of indigenous neritic species (as Acarti clausi) by the newly arriving non indigenous brackish species Acartia tonsa occurred and showed a positive correlation with temperature and Secchi disk depth and negative correlation with streamflow.
Acartia tonsa were not observed in the inner estuary of Bilbao until 2002. By 2003, it had colonized this inner estuary becoming the dominant copepod and displacing the indigenous neritic congener A. clausi to the outer estuary. The species have been found to be able to inhabit low oxygen waters (see Roman & al., 1993; Marcus & al., 2004; Itoh & al., 2011) although severe hypoxia can cause lethal effects.
Species Acartia (Acanthacartia) tonsa - Distribution map 33Issued from : E. Rice, H.G. Dam & G. Stewart in Estuaries and Coasts, 2014. [p.17, Fig.2, A, B; Fig.3, C].
A: Inshore Central Basin of Long Island Sound trend of temperature over 1978-2012. Correlation coefficient (tau) = 0.49, p <<0.01. Line shownh is the best fit, slope = 0.03, intercept = -43.2. N = 63. Data from the NOAA Milford Laboratory.
B: Off shore surface temperatures for Central Basin stations (mean and 2SD) for 1994-2012 and reported values from Riley & al. (1986) for 1952-1954.
C: Box-and-whisker plot of mean prosome lengths (µm) of Acartia tonsa in August, September and November 1952, 2010, and 2011. The thick, center line in each box represent the first and third quartiles, respectively; dashed lines represent the range; and open circles are outlies.
Species Acartia (Acanthacartia) tonsa - Distribution map 34Issued from : P.M. Ruz, P. Hidalgo, S. Yàñez, R. Escribano & J.E. Keister in J. Mar. Syst., 2015, 148. [p.208, Fig.6].
Temporal changes of female abundance (Ln number per m3), egg abundance (number per L) and egg production rate in situ samples (EPR) (Ln eggs per female per day) for Acartia tonsa in Mejillones Bay (23°S, 70°25'W).
Species Acartia (Acanthacartia) tonsa - Distribution map 35Issued from : S. Besiktepe & H. G. Dam in Mar. Ecol. Prog. Ser., 2002, 229. [p.155, Fig.2].
Acartia tonsa. Maximum clearance rate (mean ± SD, n= 6to 10) versus mean food particle equivalent spherical diqmeter (ESD). Each ESD corresponds to a different diet (see Table 1).
Copepods cultured in the laboratory, from eggs of females collected from Long Island Sound (USA).
Species Acartia (Acanthacartia) tonsa - Distribution map 36Issued from : S. Besiktepe & H. G. Dam in Mar. Ecol. Prog. Ser., 2002, 229. [p.153, Table 1].
Summary of diets and concentrations used in experiments of Acartia tonsa. ESD = equivalent spherical diameter. Values in parentheses are standard deviation of triplicate replicates. NMFS = National Marine Fisheries Service; CT: Connecticut; LIS = Long Island Sound; WHOI = Woods Hole Oceanographic Institution.
Species Acartia (Acanthacartia) tonsa - Distribution map 37Issued from : S. Besiktepe & H. G. Dam in Mar. Ecol. Prog. Ser., 2002, 229. [p.154, Fig.1].
Acartia tonsa. Functional response versus diet. (a) Ingestion rate (I) versus food concentration. (b) Clearance rate (f) versus food concentration.
Each point represents the mean ± SD of 6 to 10 replicates.
Regressions represent the Ivelev model fits to the data.
Species Acartia (Acanthacartia) tonsa - Distribution map 38Issued from : S. Besiktepe & H. G. Dam in Mar. Ecol. Prog. Ser., 2002, 229. [p.156, Fig.3].
Acartia tonsa. Fecal pellet production (FPP) and size versus diet. (a) Daily fecal pellet production versus food concentration.(b) Volume of individual pellets versus food concentration. (c) Total pellet volume versus food concentration.
Each point represents the mean # SD of 6 to 10 replicates
Species Acartia (Acanthacartia) tonsa - Distribution map 39Issued from : S. Besiktepe & H. G. Dam in Mar. Ecol. Prog. Ser., 2002, 229. [p.156, Fig.3].
Acartia tonsa. Fecal pellet production (FPP) and size versus diet. (a) Daily fecal pellet production versus food concentration.(b) Volume of individual pellets versus food concentration. (c) Total pellet volume versus food concentration.
Each point represents the mean # SD of 6 to 10 replicates
Species Acartia (Acanthacartia) tonsa - Distribution map 40Issued from : S. Besiktepe & H. G. Dam in Mar. Ecol. Prog. Ser., 2002, 229. [p.158, Fig.5].
Acartia tonsa. Estimated gut passage time versus food concentration as a function of diet.
Each point represents the mean ± SD of 6 to 10 replicates.
Species Acartia (Acanthacartia) tonsa - Distribution map 41Issued from : S. Besiktepe & H. G. Dam in Mar. Ecol. Prog. Ser., 2002, 229. [p.160, Fig.6].
Acartia tonsa. Estimated carbon assimilation efficiency versus food concentration as a function of diet.
Each point represents the mean ± SD of 6 to 10 replicates.

Assimilation efficiency (AE) = (1- E/I) x 100; where E and I are the defecation and ingestion rayes, respectively.
From this definition, AE is derived from knowledge of 3 parameters measured: ingestion rate, pellet production rate and pellet volume. AE = [1 - ((F x V x D x CW x DW)/ I] x 100.
F is the defecation rate (number of fecal pellets per copepod per day), V is volume of fecal pellets (µm3 per pellet), D is density (specific gravity of fecal pellets (% of dry weight), DW is the dry weight (% of wet weight) and I is the ingestion rate (µgC per copepod per day)
Values of D used were the mean pellet densities of eavh diet measured by Feinberg & Dam (1998). DW was assumed to be 30% of the weight of the pellet (V x D) and CW was assumed to be 25% od DW (Morales, 1987)
Species Acartia (Acanthacartia) tonsa - Distribution map 42Issued from : S. Hylander, J.C. Grenvald & T. Kiørboe in Functional Eclogy, 2014, 28. [p.154, Fig.4]. Egg and nauplli production per female over time (days) function of UVR and diets.

After Hylander & al. (2014) the life cycle from hatched egg to death lasted for ± 60 days at salinity of 27 and 18°C temperature. Copepods are known to accumulate sunscreens (so-called mycosporine-like amino acids, MAAs) and antioxydant carotenoids to mitigate negative effects of ultraviolet radiation (UVR). Cohots are followed and assessed how fitness was affected by UVR exposure and a diet rich in UVR-protective sunscreens. Copepods respond to UVR by changing the resource allocation to different fitness components resulting in reduced somatic growth, egg quality and nauplii production. Availability of sunscreens in the food source (MAAs) enables copepods to maintain high or even an elevated fitness when exposed to UVR. This illustrates that fitness coasts of UVR are diet dependent and may be considerable if UVR sunscreens are not available in the food source. Concentrations of other kinds of UVR-protective compounds such as carotenoids, are generally lower in marine than those in freshwater copepods, which suggest that predation is intense on pigmented specimens in the ocean, because the water's transparency and predation pressures are different.
Falkland Is., Ushuaia, Beagle Channel, Magellan Strait, Magallanes region, Patagonia, Peninsula Valdés, Mar del Plata, Argentina (Bahia Blanca estuary), Uruguay (Laguna de Rocha, continental shelf), off Rio de la Plata, Brazil (paranagua Bay,Vitoria Bay, Guanabara Bay, Mucuri estuary, Saco de Mangueira, Lagoa dos Patos Cananeia Lagoon, Curuça estuary, Ajuruteua Beach, Taperaçu estuary, Amazon estuary, off Amazon), Guyana (Kourou), off Angola, Congo, G. of Guinea (Liberia, Ghana), Morocco-Mauritania, Caribbean Colombia, Cariaco Basin, Venezuela, Jamaica, Caribbean Sea (Yucatan), Chelem lagoon, Colombia (Laguna Navio Quebrado), G. of Mexico, La Habana Bay, Turkey Point, off Timbalier Island, Mississipi (off Southwest Pass), Mississipi River (plume), Jamaica, Porto-Rico, Savannah River Estuary, Florida, Bayboro Harbor, Wassaw Sound, off Bermuda, Port Aransas Channel (Texas); Miami, Patuxent River estuary, Avery Point, off Maryland, Wilmington River estuary, Newport River estuary, Patuxent River, Beaufort (Inlet, Gallants Channel), Chesapeake Bay, Hampton River, Delaware Bay, Long Island Sound, Narragansett Bay, Great Bay, New York, Long Island, off Woods Hole, Damariscotta esuary, Perch Pond, Buzzards Bay, Cap Cod, Nova Scotia, Bras d'Or Lake, Morrison's Pond, Shédiac Bay, Northumberland Strait, G. of St. Lawrence, North Sea, Baltic Sea, Gulf of Mecklenburger, Bay of Kiel, Schlei Fjord, Elbe (estuary), Dunkerque Harbour, English Channel, Southampton, Bay of Biscay (Arcachon), Gironde Estuary, Bilbao estuary, Portugal (Ria de Aveiro, Mondego estuary), Medit. (Berre Lagoon, Livorno, Lake Faro, G. of Gazbes, NW Adriatic Sea: Po estuary, Lagoon of Venezzia, Koper Harbour, Lebanon Basin, Marmara Sea, Black Sea, Sevastopol Bay, Azov Sea), Caspian Sea, Indian (Maldive Is.), Singapore, Indonesia-Malaysia, Caroline Is., Vancouver Is., off Washington coast, Oregon (Yaquina, off Newport), San Francisco (Bay and Estuary), Monterey Bay, Los Angeles (San Pedro Bay), San Diego (Bay), off La Jolla, W Baja California (Bahia Magdalena), G. of California (N & Centre, lagoon Agiabampo: Sonora, Coyuca lagoon: Guerrero), W Mexico, E Australia, Pacif. S (NPFZ), Bahia Cupica (Colombia), Galapagos-Ecuador, off Peruvian coast, Chile ( N, off Concepcion, Mejillones Bay, Valparaiso, off Santiago)
N: 449
(16) F: 1,12-0,9; (36) F: 1,27-1,1; M: 1,12-0,98; (46) F: 1,5-1,3; M: 1,05; (142) F: 1,5-1,2; M: 1,1-1; (145) F: 1,4; M: 1,34; (179) F: 0,97-0,87; M: 0,8-0,77; (187) F: 1,4-1,12; M: 1,14-1,03; (188) F: 1,5-1,3; M: 1,05; (237) F: 1,25; M: 1,0; (237 as giesbrechti*) F: 1,0; (253) F: 0,98-0,821; M: 0,84-0,786 [Black Sea]; F: 1,15-1,029; M: 1-0,91 [S Adriatic Sea]; (817) F: 1,25; M: 1,09; (254) F: ±1,25; M: ±1; (861) F: 1,44-1,46; M: 1,21-1,23; (1125) F: 1,0-1,2; {F: 0,821-1,50; M: 0,77-1,34}
Rem.: coastal, ± brackish. Neritic.
Remy, 1927 a (p.177 & further) has analysed the geographic distribution of this species from its description in the Bay of Port-Jackson (Australia). He deduces that localizations, notably alongside European coasts, may be due to ship's transport. Recently, Carlton & Geller (1993, p.78) and Mauchline (1998, p.505 ) give some examples.
After Arcos (1976) the species is present in the Magallanica region with a range of temperature 5.05°C to 5.78°C and salinity 30.40 to 30.58 p.1000.
Zillioux & Gonzalez (1972) were the first to report the presence of "dormant eggs" of pelagic copepods in marine sediments.
The female P5 may show anomalies (see Behrends et al., 1997).
According to Bowman (1965, p.150) environmental conditions may affect the development of the rostral filaments (Fleminger informs that he has noticed that the rostral filaments are weak and often difficult to see in specimens of A. tonsa from coastal waters of the Gulf of Mexico where salinities are near the lower limits of tolerance); It is possible that A. floridana Davis (1948), which closely resembles A. tonsa but lacks rostral filaments, is an ecophenotype of A. tonsa.
According to Brylinski (2009, p.256) this species develops in warm and brackish waters (as harbour) and was never recorded in the Strait of Dover.

After Saiz & Kiørboe (1995) , because feeding behaviour is specific to the prey (phytoplankton vs motile prey), and because ambush-mode feeding is much more dependant on turbulence than suspension-mode feeding, it is suggested that prey selection in A. tonsa may be partly governed by turbulence in the ocean.
After Gubanova & al. (p.5) this species appeared in the Black Sea in the early 1970s is supposed replaced the native Paracartia latisetosa, because these species occupied the same ecological niche, but the alien A. tonsa was apparently more resistant to pollution and eutrophisation.
After Chaalali & al. (2013, p.2) Acartia tonsa , first introduced in 1983 by ballast waters, is an example of species that found suitable conditions to establish in the Gironde estuary (France), ecosystem characterized by a strong spatial and temporal variability in both physical and chemical proprerties and anthropogennic pressures (see in David & al., 2007 a, p.429).
After Drillet & al. (2011, p.831-836) conclude that commercial preparations with probiotic effects improve the performance of copepods in cultures. The addition of microbial preparation to the algal food increased the individual size of the adult females and their egg production/
Peoduction :
After Pastorinho & al. (2003) from Mondego estuary (Portugal) : 43/12 mgC per m3 per year. P/B = 11.
Last update : 05/11/2018
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Razouls C., de Bovée F., Kouwenberg J. et Desreumaux N., 2005-2019. - Diversity and Geographic Distribution of Marine Planktonic Copepods. Sorbonne University, CNRS. Available at http://copepodes.obs-banyuls.fr/en [Accessed June 19, 2019]

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