Species Card of Copepod
Calanoida ( Order )
    Calanoidea ( Superfamily )
        Megacalanidae ( Family )
            Bradycalanus ( Genus )
Bradycalanus typicus  A. Scott, 1909   (F, M)
Syn.: ? Bradycalanus sp. juv. Sewell, 1947 (p.30);
Megacalanus princeps : Wilson, 1932 a (p.26, figs.F);
Megacalanus typicus : Vervoort, 1946 (p.58, figs.F, juv., Rem.); Owre & Foyo, 1964 (p.343, 344, figs.F, Rem.);
? Bradycalanus pseudotypicus Björnberg, 1968 (p.82, figs.F, juv.5);
Non Bradycalanus pseudotypicus enormis Björnberg, 1968 (p.85, figs.F,M)

Synonymies after Bradford-Grieve & ak. (2017, p.59):
Bradycalanus typicus A. Scott, 1909 (p.14-16, pl.1, figs 1-11)
Megacalanus princeps (Brady, 1883) : Sars, 1924/25 (pp.14-15, Pl. III, figs 1-12).
Megacalanus sarsi Farran, 1939 (pp 355-356).
Megacalanus typicusBradycalanus pseudotypicus Björnberg, 1968 (pp 82-85, figs 55-63).
Bradycalanus sarsi : Brodsky & al. (pp199, fig.88: F).
Bradycalanus typicus : Michel, 1994 (pp 180-181).
Non Megacalanus princeps Wolfenden, 1904
A. Scott, 1909 (p.14, Descr.F, figs.F); Vervoort, 1946 (p.49); Owre & Foyo, 1967 (p.34, figs. Juv.4F); Michel, 1994 (p.180, Rem.); Bradford-Grieve & al., 1999 (p.877, 906, figs.F); Bradford-Grieve & al., 2017 (p.59, Descr., figs. F, M, phylogeny); ? Fornshell & Ferrari, 2014 (p.114, fig.11: Von Vaupel klein's organ).
Species Bradycalanus typicus - Plate 1 of morphological figuresissued frm : A. Scott in Siboga-Expedition, 1909, XIX a. [Plate I, Figs.1-11].
Female (from Halmahera Sea): 1, habitus (dorsal); 2, last thoracic and genital segments (left side); 3, A2; 4, Md; 5, Mx1; 6, Mx2; 7, Mxp; 8, P1; 9, P2; 10, P4; 11, P5.
Bar: Natural size.
Nota: Head and 1st thoracic segment separated, 4th and 5th completely separated. 5th thoracic segment is produced posteriorly in distint points. Abdomen 4-segmented, symmetrical, equal to one-third of the length of the cephalothorax. Genital segment longer than wide, nearly equal to the combined lengths of 2nd and 3rd segments.. The 2nd segment is about half the length of the genital segment. The 3rd segment is equal to two-thirds of the lonength of the 2nd. The 4th segment is about half as long as the 3rd. Caudal rami short and slightly longer than broad but rather longer than the anal segment. A1 25-segmentd, extend beyond the end of the urosome by at least 4 segments.

Species Bradycalanus typicus - Plate 2 of morphological figuresissued from : H.B. Owre & M. Foyo in Fauna Caribaea, 1, Crustacea, 1: Copepoda. Copepods of the Florida Current. 1967. [p.34, Figs.166-168]. Redrawings after A. Scott, 1909.
Female (from 23°38'N, 83°06'W): 166, habitus (dorsal); 167, P1; 168, P5.

Species Bradycalanus typicus - Plate 3 of morphological figuresIssued from : H.B. Owre & M. Foyo in Fauna Caribaea, 1, Crustacea, 1: Copepoda. Copepods of the Florida Current, 1967. [p.12, Fig.116].
Female: 16, Mx1
1st inner lobe = arthrite on the praecoxa; 2nd inner lobe: on the coxal endite and outer epipodite or 2nd outer lobe; Bsp 2 = Basis, 3rd lobe = basal endite, and basal exite; Enp = endopod with segments more or less fused; Exp = exopod.

Species Bradycalanus typicus - Plate 4 of morphological figuresIssued from : J.M. Bradford-Grieve, L. Blanco-Bercial & G.A. Boxshall in Zootaxa, 2017, 4229 (1). [p.60, Fig. 30].
Female: A-B, habitus (dorsal and lateral, respectively); C, anterior head (lateral); D, exopod of A2.
Scale bars: 1.0 mm (A, B); 0.1 mm (C, D)
D: specimens from 25.082°S, 09.584°E; A-C: specimens from 20.933°N, 138.533°E.

- Forehead rounded in dorsal view, without projection.
- A1 extending about 7 segments beyond caudal rami.
- Genital double-somite, in dorsal view, widest at anterior 1/3.
- A2 exopod segments I-III each with short but well-developed seta, segment IV with well-developed seta extending as far as distal border of segment VIII.
- Mx1 with coxal endite with 5setae, one of them short; endopodal segment 2 with 1 long and 1 vestigial seta.
- P1 exopodal segment 3, about 2.7 times as long as maximum width; distal border of endopodal segment 1 not extending beyond exopodal segment 1; exopod outer spines: on segment 1 rxtends less than half way along segment 2; on segment 2 extends half distance to 1st spine on segment 3; segment 3 proximal spine extends almost base of distal spine.

Species Bradycalanus typicus - Plate 5 of morphological figuresIssued from : J.M. Bradford-Grieve, L. Blanco-Bercial & G.A. Boxshall in Zootaxa, 2017, 4229 (1). [p.61, Fig. 31].
Male: A-B, habitus (dorsal and lateral, respectively); C, caudal ramus (dorsal); D, P1.
Scale bars: 1.0 mm (A, B); 0.1 mm C, D.

- Forehead rounded in dorsal view.
- Pediger 5 rounded in lateral view.
- P1 outer border spines on exopodal segments 1 and 2 extend half way to base of following spine; 1st outer spine inserted at 2/3 distance along outer border of exopodal segment 3 and extending beyond base of outer distal spine; distal border of endopodal segment 1 level with distal border of exopôdal segment 1.

Species Bradycalanus typicus - Plate 6 of morphological figuresIssued from : K.A. Brodsky , N.V. Vyshkvartzeva, M.S. Kos & E.L. Markhaseva in Opred. Fauna SSSR, Isdav. Inst. Zool., Acad. Sci. SSSR, 1983, 135 (1). [p.198, Fig.88]. As Bradycalanus sarsi.
Female (from N Pacif.): habbitus (dorsal); R, rostrum; Ce, anterior head (lateral), Mx1; Mx2; P1, P3, P5.
Nota: A1 25-segmented.

Species Bradycalanus typicus - Plate 7 of morphological figuresIssued from : T.K.S. Björnberg in Antarct. Res. Ser., 1968, 11. [p.84, Figs 55-63].
As Bradycalanus pseudotypicus.
Female (from SW Valdivia, Chile): 55 A B, habitus (lateral and dorsal, respectively); 56, last thoracic segments and urosome (lateral), another specimen; 57, Mx1; 583, Mx2; 59, mouth plate; 60, rostrum (ventral); 61, A2; 62, Md blade; 63, Mxp.

Nota: A1 25-segmented.

Species Bradycalanus typicus - Plate 8 of morphological figuresIssued from : T.K.S. Björnberg in Antarct. Res. Ser., 1968, 11. [p.84, Figs 55-63].
As Bradycalanus pseudotypicus.
Female A1: Proportional lengths of the segments

Species Bradycalanus typicus - Plate 9 of morphological figuresIssued from: G.O. Sars in Résult. Camp. Scient. Prince Albert I, 69, pls.1-127 (1924). [Pl.III, fig. 1]. As Megacalanus princeps ( Brady, 1883).
Female: 1, habitus (dorsal); 2, forehead (lateral); 3, rostrum (fontal view); 4, A2; 5, labrum and labium (ventral view); 6, Md; 7, Mx1; 10, P1; 11, P3; 12, P5.8, Mx2; 8a, distal portion of a seta of Mx2 (enlarged); 9, Mxp.

Species Bradycalanus typicus - Plate 10 of morphological figuresIssued from : V.N. Andronov in Russian Acad. Sci. P.P. Shirshov Inst. Oceanol. Atlantic Branch, Kaliningrad, 2014. [p.36, Fig.9, 1]. As Bradycalanus sarsi Farran, 1939 (after Sars, 1924 as Megacalanus princeps Pl.III, fig.4).
1, A2.

Species Bradycalanus typicus - Plate 11 of morphological figuresIssued from : J.M. Bradford-Grieve, L. Blanco-Bercial & G.A. Boxshall in Zootaxa, 2017, 4229 (1). [p.66, Table 8].
Morphological characters after identification key of Bradycalanus females and males.
Compare to other species of genus.

Main characters identification after species key :
1 - Head rounded; posterior pediger 5 corners triangular in lateral view; Mx1 coxal endite with 5 setae.
2 - Female A1 long extending about 6-7 segments beyond caudal rami; P1 exopod segment 1 and 2 with outer border spines short extending well short of base of following spine.
3 - Female total body length < 13 mm; male right P5 exopod segment 3 inner border spine inserted opposite outer border spine with notch.

Species Bradycalanus typicus - Plate 12 of morphological figuresIssued from : J.M. Bradford-Grieve, L. Blanco-Bercial & G.A. Boxshall in Zootaxa, 2017, 4229 (1). [p.62, Fig. 32].
Male right A1 ancestral segments: A, segments I-XIV; B, segments XV-XIX; C, segments XX-XXVIII; D, detail segments XIX-XX; E, detail segments XXI-XXIII; F, detail segment XXVIII.
Scale bars: 1,0 mm (A-C); 0.1 mm (D, E, F).
Illustrated specimen from 38.033°N, 124.183°W.

- A1 extending about 2-3 segments beyond caudal rami; ancestral segments II-IV, Ix-XI and XXI-XXIII fused, double aesthetascs on ancestral segments I, III, V, VII, IX, XI-XIV. Right antennule geniculate between ancestral segments XX-XXI, setation of gripping elements: XIX- 1 fused gripping element extending as far as base of aesthetasc, 1ms, 1a; XX-1 gripping element, 1ms, 1z; XXI-XXIII- 2 short gripping elements, 2nd extending slightly beyond base of aesthetasc, 1a, 1 unknown element, 1ms.

Species Bradycalanus typicus - Plate 13 of morphological figuresIssued from : J.M. Bradford-Grieve, L. Blanco-Bercial & G.A. Boxshall in Zootaxa, 2017, 4229 (1). [p.63, Fig. 33].
Male left A1 ancsetral segments: A, segments I-XIII; B, hair sensilla of dorsal surface of ancestral segment V; segments XIV-XVIII; D, segmentsXIX-XXVIII; E, P5 male ( arrow indicates notch); F, distal inner corner of left P5 male exopod segment 2; G, distal inner corner of left P5 male exopod segment 2 (another specimen from USNM1208043).
Scale bars: 1.0 mm (A, C, D); 0.1 mm (E, F, G).

- P5 left exopodal segment 2 specialised seta tapering, extending short of distal border of endopodal segment 3, with small proximal tapering projection; inner border of left exopodal segment 3 setulose with inner articulated spine inserted just proximal to 2nd outer (terminal) spine; inner border of right exopodal segment 3 naked, inner articulated spine inserted opposite 1st outer border spine, small notch in inner border level with distal border of right endopod.

Species Bradycalanus typicus - Plate 14 of morphological figuresIssued from : J.M. Bradford-Grieve, L. Blanco-Bercial & G.A. Boxshall in Zootaxa, 2017, 4229 (1). [p.64, Fig. 34].
Male: A, A2; B, Md palp; C, Md gnathobase; D, Mx1; R, details of basal endites 1 and 2 (B1, B2) of mx1.
Scale bars: 0.1 mm on all figures.
Illustrated specimens from 38.033°N, 124.183°W.

- A2 exopod segments I-IV each withy less well-developed seta than in female.
- Mx1 endopodal segment 1 with 1 large and 1 vestigial seta; segment 2 with 1 seta.

Species Bradycalanus typicus - Plate 15 of morphological figuresIssued from : J.A. Fornshell & F.D. Ferrari in Crustaceana, 2014, 87 (1). [p.105, Fig.1, A-C]. As Megacalanus longicornis
Von Vaupel Klein's organ on right endopodal segment 1 and left basal seta of P1. A, anterior, distal up; B, right basal seta; C, proximal endopodal segment of right P1, denticles and pores showed (ventral seta not drawn) .
Long scale line; 175 µm; short scale line 290 µm.

The Von Vaupel Klein organ is an association (srtucture) of the distal seta from basis and the proximal endopodal segment of P1.
This structure shows significant variability among many gymnoplean copepods, in the shape of the distodorsal corner of the proximal endopodal segment, presence and location of denticles on the anterior face of the segment, presence and size of denticles along the distal margin of the segment , number of pores on the segment, shape of the seta that originates on the basis, and the morphology of the basis at the origin of the seta.
The function of this complex structure is not known.

Compl. Ref.:
Grice & Hulsemann, 1967 (p.13); 1968 (tab.2); Razouls & al., 2000 (p.343, Appendix)
NZ: 13

Distribution map of Bradycalanus typicus by geographical zones
Antarct. (SW Atlant.), Drake Passage, off Namibia, Barbada Is., Caribbean, Florida, G. of Aden, Arabian Sea, NW Indian, off E Réunion Is., Indonesia-Malaysia ( Halmahera Sea, Flores Sea), SE Pacif. (off Juan Fernandez Is.), SW Valdiviella (Chile), off California, off SE Japan
N: 8
(5) F: 9; (28) M: 11; (85) F: 15,5; (131) F: 11-12; (406) F: 12,5-13,75; (1316) F: 11,5-13,9; M: 9,4-11,3; {F: 9,00-15,50; M: 6,4-11,3}
Rem.: Bathypelagic.
Sampling depth (Antarct.) : 1000-2000 m.
Sars (1925, p.14) considers this species as a synonym of B. sarsi (like Calanus princeps Brady, 1883, then Megacalanus princeps (Brady), no Wolfenden,1904. He was followed by Jespersen (1934, p. 45). The geographic distribution of the two species seem to confirm this point of view, although the references are rare. However, the presence of posterior pointed teeth on the last thoracic segment permits to distinguish between the two species.
Park & Ferrari (2009, p.174) do not admit the synonymy between this species and Bradycalanus pseudotypicus enormis Björnberg 1968.
For Bradford-Grieve & al. (2017, p.65), all females examined vary from about 10.3 mm to about 14 mm. There was very little variability in the morphology apart slight differences in the form of the posterior border of pedigerous soite 5 which ranges from rounded to bluntly triangular though to a pointed triangle. On P1, the outer border spines of the exopod segments vary in length although the outer border spines of exopodal segments 2 and 3 never extend beyond the base of the spine more distal to it.
Last update : 14/09/2018
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Razouls C., Desreumaux N., Kouwenberg J. and de Bovée F., 2005-2024. - Biodiversity of Marine Planktonic Copepods (morphology, geographical distribution and biological data). Sorbonne University, CNRS. Available at http://copepodes.obs-banyuls.fr/en [Accessed July 25, 2024]

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