Gaetanus pileatus - Species Card - Marine Planktonic Copepods

Gaetanus pileatus Farran, 1903 (F,M)

Taxonomy

Order Calanoida

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Superfamily Clausocalanoidea

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Family Aetideidae

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Genus Gaetanus

details list species for this Genus

Abbreviations or symbols

Synonymy

Gaetanus Caudani Canu, 1896 (? p.422, juv.M); Wolfenden, 1904 (p.132, figs.F, Rem.); 1905 a (p.8, fig.F); Pearson, 1906 (p.13, Rem.); A. Scott, 1909 (p.46, figs.F, Rem.); Giesbrecht & Schmeil, 1898 (p.33: Rem. juv. M); Pearson, 1906 (p.13); A. Scott, 1909 (p.46, figs.); Lysholm & Nordgaard, 1921 (p.14);
Gaetanus unicornis Esterly, 1906 a (p.57, figs.F); Wilson, 1936 c (p.90); Brodsky, 1950 (1967) (p.167, figs.F); Lee & al., 1971 (p.1150);
Gaetanus clarus Esterly, 1906 a (p.57, figs.M); Brodsky, 1950 (1967) (p.166, figs.M);
Gaetanus recticornis Wolfenden, 1911 (p.228, fig.F); C.B. Wilson, 1950 (p.233, figs.F);
Gaetanus kruppii : Sewell, 1947 (p.62, Rem.M, figs.M, no F)

References

List of the studied authors

Farran, 1903 (p.16, Descr.F, figs.F); 1908 b (p.35, Rem.); Wolfenden, 1911 (p.229, figs.F, Rem.); With, 1915 (p.104, figs.F); Sars, 1925 (p.56, figs.F, M); Farran, 1926 (p.250); Sewell, 1929 (p.103, figs.juv., Rem.); Rose, 1933 a (p.100, figs.F,M); Farran, 1936 a (p.89); Jespersen, 1940 (p.20); Sewell, 1947 (p.56, 57, 59); Vervoort, 1952 e (p.3, figs.F,M); Tanaka, 1957 b (p.175, figs.F); Vervoort, 1963 b (p.132, Rem.); Paiva, 1963 (p.33); Owre & Foyo, 1967 (p.45, figs.F,M, Rem.); Tanaka & Omori, 1970 (p.141); Park, 1975 a (p.10, 13, 20, figs.F,M, Rem. p.21-23); 1978 (p.139, figs.F); Bradford & Jillett, 1980 (p.55, figs.F,M); Gardner & Szabo, 1982 (p.230, figs.F,M); Baessa de Aguiar, 1987 (p.44, figs.F, Rem.F); Markhaseva, 1996 (p.211, figs.F, ?M); Bradford-Grieve & al., 1999 (p.879, 922, figs.F); Boxshall & Halsey, 2004 (p.59: fig.F); Vives & Shmeleva, 2007 (p.583, figs.F,M, Rem.)

Figures

Plate 1 issued from : Tanaka O. in Publ. Seto Mar. Biol. Lab., 1957, 6 (2). [Fig.43, p.176].
Female (from Sagami): a, habitus (dorsal aspect); b, head (lateral aspect); c, last thoracic segment and urosome (lateral aspect); d, third inner lobe with 3 setae and a conical process of Mx1; e, Mxp.; f, first basal joint of P4, with 16 lamellous bristles on the inner margin.

Nota Female:
- Cephalic spine has a characteristic shape.
- Last thoracic segment with lateral spines divergent, and extend to the middle of genital segment.
- Abdomen 4-segmented ; segments and caudal rami proportional lengths 44 : 17 : 14 : 9 : 16 = 100.
- Genital segment as long as wide, showing a sudden change in the continuity of the outline at the proximal 2/5 of the dorsal surface.
- Caudal rami as long as wide.
- A2 exopod about as long as endopod..
- Mx1 with 7 long and 2 short setae on outer lobe; 3rd inner lobe with 3 setae and a conical process (at apex fig.d).
- Mxp with 1st basal segment about as long as the 2nd; 1st segment with a lamellous process with a rounded tip on posterior margin.
- P1 exopod 2-segmented with no articulation between 1st and 2nd segments.
- P2 exopod 3-segmented and endopod 2-segmented; the number of teeth on terminal spine of P2 to P4 with 20, 20, and 23 respectively.
- P4 with coxa bearing about 16 lamellous bristles on the inner margin

Species Gaetanus pileatus - Plate 2 of morphological figures

Plate 2 issued from : T. Park in Antarctic Res. Ser. Washington, 1978, 27. [p.140, Fig.23].
Female: A, habitus (dorsal); B, forehead (lateral); C, posterior part of metasome and urosome (right lateral side); D, A2; E, Md; F, Mx1; G, Mx2.

Species Gaetanus pileatus - Plate 3 of morphological figures

Plate 3 issued from : T. Park in Antarctic Res. Ser. Washington, 1978, 27. [p.141, Fig.24].
Female: A, Mxp; B, P1; C, P2; D, P3; E, medial part of coxa of P4 (posterior). P1-3: legs (anterior).

Species Gaetanus pileatus - Plate 4 of morphological figures

Plate 4 issued from : E.L. Markhaseva in Proc. Zool. Inst. RAN, St. Petersburg, 1996, 268. [p.213, Fig.168].
Female (from SE Pacif.). Ce: forehead (dorsal and lateral, respectively); CP4: coxopod of P4 (partial).

Species Gaetanus pileatus - Plate 5 of morphological figures

Plate 5 issued from : E.L. Markhaseva in Proc. Zool. Inst. RAN, St. Petersburg, 1996, 268. [p.214, Fig.169 ].
Male (from Indian: off NW Cocos island)

Species Gaetanus pileatus - Plate 6 of morphological figures

Plate 6 issued from : T. Park in Bull. Mar. Sci., 1975, 25 (1). [p.21, Fig.6].
Female: A, B, forehead, lateral (showing a variability of the cephalic process).
Male: C, forehead (lateral); D, posterior part of metasome and urosome (left side, lateral); E, figth legs (posterior); F, last two exopodal segments of left fifth leg (medial).

Species Gaetanus pileatus - Plate 7 of morphological figures

Plate 7 issued from : J.M. Bradford & J.B. Jillett in Mem. N.Z. Oceanogr. Inst., 86, 1980. [p.57, Fig.37].
Female: A, habitus (lateral left side); B, idem (dorsal); C, basipod 1 of Mxp; D, exopod 1 of P1; E, inner edge of basipod 1 of P4.

Male: F, habitus (lateral left side); G, idem (dorsal); H, P5.
Nota: P5 figured by Sars (1925, plate 17, fig.16) is identical to that found on a specimen of G. latifrons and not like P5 on the present male. We suggest there has been some confusion between the figures on plate 17.

Species Gaetanus pileatus - Plate 8 of morphological figures

Plate 8 Issued from: G.O. Sars in Résult. Camp. Scient. Prince Albert I, 69, pls.1-127 (1924). [Pl.XVII, figs. 3-6].
Female: 3, habitus (dorsal); 4, idem (lateral left side).

Male: 5, habitus (lateral left side); 6, P5.

Species Gaetanus pileatus - Plate 9 of morphological figures

Plate 9 issued from : R.B.S. Sewell in The John Murray Expedition, 1933-34, Scientific Reports, VIII (1), 1947. [p.63, Fig.10, A, C-F]. As Gaetanus kruppi.
Male (from Arabian Sea): A, A1; C, A2; D, Mx1; E, Mx2; F, P5.
Nota: Proportional lengths of cephalothorax and abdomen as 75 to 25. The proportional lengths of the various segments (cephalon to caudal rami) as 540:71:65:75:42:74:48:42:10:32 = 1000. Head and 1st thoracic segment fused, 4th and 5th fused.

Species Gaetanus pileatus - Plate 10 of morphological figures

Plate 10 issued from : A. Scott in Siboga-Expedition, 1909, XIX a. [Plate VIII, Figs.9-15]. As Gaetanus caudani.
Female (from Indonesia-Malaysia): 9, habitus (dorsal); 10, forehead (lateral); 11, last thoracic and genital segments (left side); 12, rostrum; 13, Mxp; 14, P1; 15, P4 (basal portion only).
Nota: The lamella on the basal segment of Mxp is narrowed at the apex and deeply excavated. The posterior margin of the first three abdominal segments is fringed with fine spines.

Species Gaetanus pileatus - Plate 11 of morphological figures

Plate 11 issued from : G.P. Farran in Scient. Invest. Fish. Brch, Ireland, 1901 (2), Appendix 7, 1903. [Plate XVII, Figs.3-8].
Female (from off Cleggan, Irelandl): 3, A2; 4, Md (cutting edge); 5, Mx2; 6, Mx1 (lower lobes omitted); 7, Mxp; 8, P1 (anterior); 8, P1 (anterior).

Species Gaetanus pileatus - Plate 12 of morphological figures

Plate 12 issued from : R.N. Wolfenden in J. mar. biol. Ass. U.K, 1904, VII (N.S.). [Pl.IX, Fig.20]. As Gaetanus caudani.
Female (from NE Atlantic): 20, habitus (dorsal).

Species Gaetanus pileatus - Plate 13 of morphological figures

Plate 13 issued from : R.N. Wolfenden in J. mar. biol. Ass. U.K, 1904, VII (N.S.). [Pl.IX, Figs.21, 22]. As Gaetanus caudani.
Female (from NE Atlantic): 21, basipod of P4; 22, P1.

Species Gaetanus pileatus - Plate 14 of morphological figures

Plate 14 issued from : R.N. Wolfenden in Die Marinen Copepoden der Deutschen Südpolar-Expedition 1901-1903, 1911. [p.228, Fig.16].As Gaetanus recticornis.
Female (from S Atlantic: off Trinidad Island): a, habitus (lateral, left side); b, posterior part cephalothorax and urosome; c, basal segment of Mxp.

Species Gaetanus pileatus - Plate 15 of morphological figures

Plate 15 issued from : R.N. Wolfenden in Die Marinen Copepoden der Deutschen Südpolar-Expedition 1901-1903, 1911. [p.230, Fig.17]. As Gaetanus recticornis
Female: a, habitus (lateral, right side); b, Mxp; c, basipod of P4.

Species Gaetanus pileatus - Plate 16 of morphological figures

Plate 16 issued from : R.N. Wolfenden in Die Marinen Copepoden der Deutschen Südpolar-Expedition 1901-1903, 1911. [Pl.XXVI, Fig.13]. As Gaetanus recticornis
Female: 13, P1.

Species Gaetanus pileatus - Plate 17 of morphological figures

Plate 17 issued from : R.N. Wolfenden in Die Marinen Copepoden der Deutschen Südpolar-Expedition 1901-1903, 1911. [Pl.XXVII, Figs.1-2].
Female:1, habitus (dorsal); 2, P1.

Species Gaetanus pileatus - Plate 18 of morphological figures

Plate 18 issued from : C.O. Esterly in Univ. Calif. Publs Zool., 1906, 3 (5). [Pl.9, Fig.5]. As Gaetanus clarus.
Male (from San Diego, California): 5, forehead (lateral).

Species Gaetanus pileatus - Plate 19 of morphological figures

Plate 19 issued from : C.O. Esterly in Univ. Calif. Publs Zool., 1906, 3 (5). [Pl.14, Fig.90]. As Gaetanus clarus.
Male: 90, P5 (right foot at left of figure).

Species Gaetanus pileatus - Plate 20 of morphological figures

Plate 20 issued from : C.O. Esterly in Univ. Calif. Publs Zool., 1906, 3 (5). [Pl.9, Fig.3]. As Gaetanus unicornis.
Female (from San Diego, California): 3, forehead (lateral).

Nota: A1 24-segmentedreacing beyond the caudal rami by at least the last 4 segments.

Species Gaetanus pileatus - Plate 21 of morphological figures

Plate 21 issued from : C.O. Esterly in Univ. Calif. Publs Zool., 1906, 3 (5). [Pl.12, Fig.54]. As Gaetanus unicornis.
Female: 54, 1st basal of Mxp.
The lamella on the 1st basal of Mxp is present, but does not have the rod-like extension of G. brevicornis or G. miles.
Nota
Nota: Exopod of P1 distinctly 2-segmented. 1st basal of P4 with tube-like bristles.

Species Gaetanus pileatus - Plate 22 of morphological figures

Plate 22 issued from : C.O. Esterly in Univ. Calif. Publs Zool., 1906, 3 (5). [Pl.13, Fig.76]. As Gaetanus unicornis.
Female: distal portion of inner margin of 1st basal of P4.

Species Gaetanus pileatus - Plate 23 of morphological figures

Plate 23 issued from : C.B. Wilson in Bull. U.S. natn. Mus., 1950, 100, 14 (4). [Pl. 23, Figs.340-341]. As Gaetanus recticornis.
Female (from Pacific): 340, habitus (dorsal); 341, forehead (lateral).

Species Gaetanus pileatus - Plate 24 of morphological figures

Plate 24 issued from : R.N. Wolfenden in Plankton Studies Part I. Copepoda. 1905 [Pl.III, 2]. As Gaetanus caudani
Female: 2, habitus (lateral).

Plate 25 Gaetanus pileatus female:
1 - Anterior part of cephalon with frontal spine.
2 - Exopodal segment 1 of A2 without seta; exopodal segment 2 with 1 seta (near distal margin). 2nd internal lobe of Mx1 with 4 setae. Exopod of P1 with 2 external spines.
3 - Mxp protopodite with lateral plate.
4 - Exopodal segment 2 of A2 with 1 seta.
5 - Spines of last thoracic segment exceeding at least the midlength of genital segment. Frontal spine large.
6 -, Frontal spine straight, not curved to rostrum by its top.
7 - Spines of last thoracic segment reaching third of genital segment length. External spine of exopodal segment 2 of P1 not reaching the midlength of the next segment.

Plate 26 Gaetanus pileatus1 - Cephalon with frontal spine.
2 - Exopodal segment 3 of left P5 prolonged, stylet-like, never bilobated. It is always longer than exopodal segment 2.
3 - Frontal spine is in anterior part of cephalon dorsally (lateral view), well visible.
4 - Spines on last thoracic segment significantly shorter than in G. simplex.
5 - Endopod of left P5 shorter than half length of exopodal segment 1.

Complementary References

List of the studied authors

Lysholm & al., 1945 (p.17); Sewell, 1948 (p.329, 500, 520, 529, 531, 539, 545, 556); C.B. Wilson, 1950 (p.233); Østvedt, 1955 (p.15: Table 3, p.63); Wickstead, 1962 (p.549, food & feeding); Grice & Hart, 1962 (p.287, table 3); Grice, 1963 a (p.495); De Decker & Mombeck, 1964 (p.12); Grice Hulsemann, 1965 (p.223); 1967 (p.15); 1968 (tab.2); Park, 1970 (p.476); Roe, 1972 (p.277, tabl.1, tabl.2); 1972 a (p.338); Bainbridge, 1972 (p.61, Appendix Table III: occurrence); Björnberg, 1973 (p.324, 386); Carter, 1977 (1978) (p.35); Deevey & Brooks, 1977 (p.256, tab.2, Station "S"); Pipe & Coombs, 1980 (p.223, figs. 1, 2, table 1, vertical distribution); Vives, 1982 (p.291); Roe, 1984 (p.357); Guangshan & Honglin, 1984 (p.118, tab.); Madhupratap & Haridas, 1986 (p.105, tab.1); Lozano Soldevilla & al., 1988 (p.58); Heinrich, 1990 (p.17); Baessa De Aguiar, 1991 (1993) (p.101); Lampitt & al., 1993 (p.689, faecal pellets v.s. ingestion); Shih & Young, 1995 (p.67); Errhif & al., 1997 (p.422); Padmavati & al., 1998 (p.347); Suarez-Morales & Gasca, 1998 a (p108); Lapernat, 2000 (tabl. 3, 4); Razouls & al., 2000 (p.343, Appendix); Madhupratap & al., 2001 (p. 1345, vertical distribution vs. O2, figs.4, 5: clusters, p.1353); d'Elbée, 2001(tabl. 1); Holmes, 2001 (p.49); Park, W & al., 2004 (p.464, tab.1); Gaard & al., 2008 (p.59, Table 1, N Mid-Atlantic Ridge); Galbraith, 2009 (pers. comm.); Park & Ferrari, 2009 (p.143, Table 5, Appendix 1, biogeography); Teuber & al., 2013 (p.1, Table 1, 2, abundance vs oxygen minimum zone, respiration rates); in CalCOFI regional list (MDO, Nov. 2013; M. Ohman, comm. pers.); Bode M. & al., 2013 (p.1, Table 1, respiration rate & ETS activity); Bonecker & a., 2014 (p.445, Table II: frequency, horizontal & vertical distributions, Table IV: new geographical record); Bode & al., 2015 (p.268, Table 1, chemical components, trophic level, geographic zone); Bode & al., 2018 (p.840, Table 1, respiration & ingestion rates, depth)

Distribution

NZ: 20

Distribution map of Gaetanus pileatus by geographical zones

Distribution map of Gaetanus pileatus for the Zone Indian Ocean
Distribution map of Gaetanus pileatus for the Zone China Seas, Vietnam
Distribution map of Gaetanus pileatus and for the Zone Sub-Antarctic

Additional Maps & Charts

Map 5 Issued from : J.M. Bradford & J.B. Jillett in New Zealand Ocean. Inst. Memoir, 86, 1980. [p.87, Figs.63].
Distribution of several species of Gaetanus in the Tasman Sea and around New Zealand.

Map 6 Issued from : M. Bode, R. Koppelmann, L. Teuber, W. Hagen & H. Auel inGlobal Biogeochemical Cycles, 2018, 32. [p.844, Table 1).
Cf. explanations of these measures in Calanoides natalis from the same authors.
Compare with Gaetanus brevicornis, G. kruppii.

Map 7 Issued from : M. Bode, A. Schukat, W. Hagen & H. Auel in J. Exp. Mar. Biol. Ecol., 2013, 444. [p.3, Table 1].
Dry mass, individual respiration rate and ETS activity from the northern Benguela Current upwelling system along transects at 23°S and 26°40'S, off Walvisbay and Lüderitz (Namibia).

Localisations

Geographical glossary

sub-Antarct. (Indian, SE Pacif.), South Africa (E), off E Tristan da Cunha, Angola, Congo, off E Sao Tomé Is. Brazil (off Rio de Janeiro), G. of Guinea, off Lagos, Cape Verde Is., off Mauritania-NW Cape Verde Is., off Morocco-Mauritania, Canary Is., off Madeira, off Portugal, off W Cabo Finisterre, Azores, Barbada Is., Caribbean Sea, G. of Mexico, Florida, off Bermuda: Station "S" (32°10'N, 64°30'W), Sargasso Sea, W Ireland, Greenland, Iceland, Faroe Is., Norwegian Sea, Bay of Biscay, Arabian Sea, Laccadive Is., Natal, off SW Sri Lanka, Indian, S Indian (subtropical convergence), Indo-Malaysia, Philippines, China Seas (East China Sea, South China Sea), Japan (Izu), Pacif. (W equatorial), Australia (Great Barrier), New Zealand, Hawaii, Vancouver Is., California, off Galapagos, off Peru, Pacif. (SE tropical), off Juan Fernandez Is., Chile. Wyville Thomson Ridge (in Pipe & Coombs, 1980, Arctic).

Type locality: NE Atlantic (SW Ireland Slope).

Quotations

N: 75

Dimensions (mm)

References of the authors concerning dimensions

(1) F: 6,2; M: 4,7; (5) F: 6; (7) F: 5,74; (10) F: 5-4,6; (14) F: 6,1-5,9; M: 5,3-4,8; (17) F: 6,5; M: 5,3; (29) F: 4,1; (37) F: 6,7-4,9; M: 5,08-4,44; (38) F: 5,4-5,3; (40) F: 6,41-4,92; M: 5,08-4,44; (56) F: 6,14; (73) F: 5,82; (89) F: 5,93; (113) F: 6-5,5; (199) F: 6,56-5,55; M: 4,96-4,64; (201) F: 6,65-5,5; M: 4,85; 4,8; (249) F: 6,1-6; {F: 4,10-6,70; M: 4,44-5,30}

Remarks

Meso-bathypelagic. Sargasso Sea: 500-1000 m (Deevey & Brooks, 1977, station "S"); 500-580 m (Pipe & Coombs, 1980 in Arctic).
Sampling depth (sub-Antarct.) : 0-1000 m.
According to Østvedt (1955) this species have not previously been taken from this northern latitude of the Norwegian Sea.
Reported by Park, W & al. (2004) in the Gulf of Alaska (Icy Strait).
Farran's type specimen was obtained from the stomach of a mackerel, and even a very short exposure to the gastric juices would bring some changes in the appearance of the copepod. The only difference between Farran's figures and those given by A. Scott, appears to be in the setting of the cephalic spine.

Last update : 15/01/2021

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