Gaetanus antarcticus - Species Card - Marine Planktonic Copepods

Gaetanus antarcticus Wolfenden, 1905 (F,M)

Taxonomy

Order Calanoida

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Superfamily Clausocalanoidea

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Family Aetideidae

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Genus Gaetanus

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Abbreviations or symbols

Synonymy

Gaetanus antarctica Wolfenden, 1905 a (p.7, Descr.F, fig.F),
no G. antarcticus Brady, 1918 (p.19);
Gaetanus brevicaudatus Wolfenden, 1911 (p.227, figs.F);
Gaetanus wolfendeni Park, 1975 a (p.12);
Gaidius robustus : Grice & Hulsemann, 1967 (p.24, figs.60-64: M)

References

List of the studied authors

Wolfenden, 1911 (p.229); Farran, 1929 (p.208, 233, Rem.: juv.); Sewell, 1947 (p.58, 65, figs.F, Rem.); Vervoort, 1957 (p.62, figs.F, Rem.); Tanaka & Omori, 1970 (p.131, figs. juv.M); Park, 1978 (p.141, figs.F); Bradford & Jillett, 1980 (p.48); Björnberg & al., 1981 (p.605, 630, figs.F); Markhaseva, 1996 (p.178, figs.F,M); Bradford-Grieve & al., 1999 (p.879, 922, figs.F,M)

Figures

Plate 1 issued from : T. Park in Antarctic Res. Ser. Washington, 1978, 27. [p.142, Fig.26].
Female: A, habitus (dorsal view); B, idem (right lateral side); C, A2; D, Md; E, Mx1; F, Mx2.

Species Gaetanus antarcticus - Plate 2 of morphological figures

Plate 2 issued from : T. Park in Antarctic Res. Ser. Washington, 1978, 27. [p.143, Fig.21].
Female: A, Mxp; B, P1; C, P2; D, P4; E, medial part of coxa of P4 (posterior view); P1-4: swimming legs (anterior view).

Species Gaetanus antarcticus - Plate 3 of morphological figures

Plate 3 issued from : E.L. Markhaseva in Proc. Zool. Inst. RAN, St. Petersburg, 1996, 268. [p.179, Fig.138].
Female (specimen from Antarctic: Indian sector). Ce: forehead (lateral); CP4: coxopod of P4 (partial).

Species Gaetanus antarcticus - Plate 4 of morphological figures

Plate 4 issued from : G.D. Grice & K. Huisemann in Proc. U.S. Nat. Mus., 1967, 122 (3583). [p.51, Figs.60-64]; As Gaidius robustus.
Male (from Indian Ocean): 60, 5th thoracic segment and urosme (dorsal); 61, idem (lateral right side); 62, forehead (lateral); 63, P5; 64, distal end of left P5.

Species Gaetanus antarcticus - Plate 5 of morphological figures

Plate 5 issued from : R.B.S. Sewell in The John Murray Expedition, 1933-34, Scientific Reports, VIII (1), 1947. [p.66, Fig.11].
Female (from Arabian Sea): A, habitus (leteral right side); B, A2; C, Mx1; D, basal segment of Mxp; E, P1; F, P4.

Nota: Proportional lengths of the prosome and urosome as 80 : 20.
- The proportional lengths of the urosome as : 37 : 19 : 17 : 11 :1 6 = 100.
- The genital and the two following segments are each prrovided with a row of spines (this row is composed of stout triangular spines across the dorsal aspect, but on the sides and below the size of the spines is much reduced.
- A1 24-segmented, segments 8 and 9 fused (in Wolfenden, 1905, p.7, there are 23 segments because segments 24 and 25 fused).
- In Mxp the lamella on the 1st basal segment is rounded at its distal end and is not produced in a hook-like process.
- In the swimming legs there are tufts of fine hairs on the anterior aspect of the distal segment of the endopod.
- Secretory glands are present on all three segments of the exopod of P2 to P4, and these open by pores situated close to the base of the marginal spine at the distal external angle.

Species Gaetanus antarcticus - Plate 6 of morphological figures

Plate 6 issued from : W. Vervoort in B.A.N.Z. Antarctic Reseach Expedition, Report Ser. B, Vol. III., 1957 [Fig.42].
Female (from 61°44'S, 77°59'E):a-b, habitus (lateral and dorsal, respectively).

Species Gaetanus antarcticus - Plate 7 of morphological figures

Plate 7 issued from : W. Vervoort in B.A.N.Z. Antarctic Reseach Expedition, Report Ser. B, Vol. III., 1957 [Fig.43].
Female: a-b, posterior part cephalothorax and urosome (lateral and dorsal, respectively); c, forehead (lateral).)

Species Gaetanus antarcticus - Plate 8 of morphological figures

Plate 8 issued from : R.N. Wolfenden in Die Marinen Copepoden der Deutschen Südpolar-Expedition 1901-1903, 1911. [p.227, Fig.15 a].
Female: a, habitus (lateral, left side).

Species Gaetanus antarcticus - Plate 9 of morphological figures

Plate 9 issued from : R.N. Wolfenden in Die Marinen Copepoden der Deutschen Südpolar-Expedition 1901-1903, 1911. [p.227, Fig.15 b]. As Gaetanus brevicaudatus.
Female: b, basal segment of Mxp.

Species Gaetanus antarcticus - Plate 10 of morphological figures

Plate 10 issued from : R.N. Wolfenden in Die Marinen Copepoden der Deutschen Südpolar-Expedition 1901-1903, 1911. [Pl.XXVI, Figs.11-12]. As Gaetanus brevicaudatus.
Female: 11, last thoracic segment and urosome; 12, P1.

Species Gaetanus antarcticus - Plate 11 of morphological figures

Plate 11 issued from : R.N. Wolfenden in Plankton Studies Part I. Copepoda. 1905 [Pl.III, 1]. As Gaetanus antarctica.
Female: 1, habitus (lateral).

Plate 12 Gaetanus antarcticus female:
1 - Anterior part of cephalon with frontal spine.
2 - Exopodal segment 2 of A2 with 1 seta; exopodal segment 2 with 3 setae. 2nd internal lobe of Mx1 with 5 setae.
3 - Exopod of P1 clearly 3-segmented; with 3 external spines. Lateral plate of Mxp protopodite well developed.
4 - Spines of last thoracic segment curved and removed ventrally (lateral view).
5 - Frontal spine short.

Plate 13 Gaetanus antarcticus male:
1 - Cephalon with frontal spine.
2 - Exopodal segment 3 of left P5 bilobated. It is 1.5-2.2 shorter than exopodal segment 2.
3 - Spines on last thoracic segment, not reaching the posterior border of genital segment. Exopodal segment 3 of P5 bilobated with complete subdivision into lobes.

Species Gaetanus antarcticus - Plate 14 of morphological figures

Plate 14 Issued from : C. Razouls in Ann. Inst. océanogr., Paris, 1994, 70 (1). [p.71]. Caractéristiques morphologiques de Gaetanus antarcticus femelle adulte.
Terminologie et abbréviations: voir à Calanus propinquus.

Complementary References

List of the studied authors

Hardy & Gunther, 1935 (1936) (p.159, Rem.: juv.); Sewell, 1948 (p.331, 532, 574); C.B. Wilson, 1950 (p.229); Grice & Hulsemann, 1967 (p.15); 1968 (tab.2); Björnberg, 1973 (p.323, 386); Arcos, 1976 (p.85, Rem.: p.93, Table II); Vives, 1982 (p.291); Hopkins, 1985 (p.197, Table 1, gut contents); Hopkins & Torres, 1988 (tab.1); Razouls & al., 2000 (p.343, tab. 5, Appendix); Schnack-Schiel & al., 2008 (p.1045: Tab.2); Galbraith, 2009 (pers. comm.); Park & Ferrari, 2009 (p.143, Table 4, Appendix 1, biogeography)

Distribution

NZ: 10

Distribution map of Gaetanus antarcticus by geographical zones

Distribution map of Gaetanus antarcticus for the Zone Indian Ocean

Distribution map of Gaetanus antarcticus for the Zone Antarctic and for the Zone Sub-Antarctic

Additional Maps & Charts

Species Gaetanus antarcticus - Distribution map 4

Map 4 issued from : W. Vervoort in B.A.N.Z. Antarctic Reseach Expedition, Reports - Ser. B, Vol. III, 1957 [Fig.41]
Chart showing the geographical distribution (white circle) in the seas surrounding the Antarctic continent.
Nota: In this chart the area frequented by whaling vessels has been hatched. The Antarctic circle (66°.5 S) has been drawn as a broken line. The numbers I to VI refer to the sectors into which the Antarctic seas are divided according to Mackintosh (1942) (after Vervoort, 1951).

Localisations

Geographical glossary

Antarct. (Croker Passage, Peninsula, Weddell Sea, SW Atlant., Indian, SW - S - SE Pacif., Mc Murdo), Magallones region (in Arcos, 1976, with doubt), sub-Antarct. (SE Pacif.), off E Trindade Is., Brazil, Argentina, off Morocco-Mauritania, Portugal, G. of Oman, Arabian Sea, Indian, ? Japan (Izu), Marquesas Is., Vancouver Is., off Juan Fernandez Is., Chile.

Type locality: 64°18'S, 90°27'E

Quotations

N: 23

Dimensions (mm)

References of the authors concerning dimensions

(10) F: 5,9; (10’) F: 8; (11) F: 8,25-7,6; (20) F: 9,08-7,91; (25) F: 8,78-8,4; (37) F: 9,08-7,6; (202) F: 8-8,48; {F: 5,90-9,08}

Remarks

meso & bathypelagic.
Sampling depth (Antarct., sub-Antarct.) : 600-1000+ m.
The strong size differences observed by Wolfenden (1911) correspond to Antarctic localities (10') and S. Atlantic (10).
For Sewell (1947, p.67) Its occurrence in the deep water at the northern end of the Arabian Sea and in the Gulf of Oman is surprising. This species is thought to be transported from Antarctica to the north by intermediate or deep currents.

Last update : 24/01/2017

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