Species Card of Copepod
Calanoida ( Order )
    Clausocalanoidea ( Superfamily )
        Aetideidae ( Family )
            Chiridiella ( Genus )
Chiridiella megadactyla  Bradford, 1971   (F)
Bradford, 1971 b (p.19, Descr.F, figs.F);
Species Chiridiella megadactyla - Plate 1 of morphological figuresIssued from : J.M. Bradford in N.Z. Oceanogr. Inst., 1971, 206, Part 8, No 59. [p.20, Figs.54-60].
Female (from 71°15'S, 176°30'E): 54, P2; 55, P3; 56-57, habitus (lateral and dorsal, respectively); 58, P1; 59, A2; 60, P4.
Scale bar: 1 mm (56, 57); 100 µm on the rest.

Nota: Head and 1st thoracic segment incompletely fused, 4th and 5th segments fused.
Posterior borders of last thoracic segment broadly rounded.
No trace of rostrum.
Genital segment laterally slightly swollen but ventrally greatly extended.
A2 endopod over half length of exopod; exopod 7-segmented (segments 1 and 2 without setae).
P1 exopod 1-segmented; exopod 1-segmented with 1 external spine, terminal seta with external small teeth and internal border of hairs.
P2 endopod 1-segmeted; exopod 3-segmented, terminal spine with about 60 very small external teeth; 3rd segment with 1 ''glandular pore'' on anterior surface in distal external corner.
P3 3-segmented, although segments 1 and 2 endopod appears immovable; ''glandular pores'' obn distal-external corners of 2nd and 3rd exopod segments; terminal spine with about 60 teeth.
P4 almost identical with P3, exopod a little broader.
external exopod spines of P2-P4 bordered by a row of small bristles.

Species Chiridiella megadactyla - Plate 2 of morphological figuresIssued from : J.M. Bradford in N.Z. Oceanogr. Inst., 1971, 206, Part 8, No 59. [p.19, Figs.49-53].
Female; 49, A1; 50, Md (mandibular palp); 51, Mx1; 52, Mx2; 53, Mxp.
Scale bars: 100 µm.

Nota: A1 23-segmented (segments 8-9, 17-18 fused), reaches past caudal rami, furnished with elongate annulate setae on segmentd 7, 8, 13, 16, 19, 21, 22, 23.
Md palp endopod bears 4 setae on terminal segment and 6 setae on exopod, basipod segments without setae.
Mx1 with setation on 1st inner lobe strongly developed, 2nd inner lobe apparently absent, 3rd lobe with 3 setae, endopod with 3 setae, exopod with 4 setae; 1st outer lobe with 8 setae.
Mx2 with 5 lobes, 2 proximal lobes with 1 seta each, while three distal lobes have enlarged spine-like setae; 3rd lobe with 1 spine, 4th lobe with 2 spines (1 shorter and thicker), 4th lobe with 2 spines (1 shorter and thicker), 5th lobe bears 1 spine carrying 2 setae.
Mxp 1st basippod segment with 1 median seta, distal corner with 1 terminal spine-like expansion, 1 short thickly plumose seta and 2 ordinary setae; remaider of setation as in Fig.53.

Species Chiridiella megadactyla - Plate 3 of morphological figuresChiridiella megadactyla female ;
1 - Penultimate lobe of Mx2 with 1 long and 1 short spine arranged as pincers.
2 - Mx2 with 4 or 5 lobes.
3 - A1 as long as, or longer than body.
4 - 1st basipod segment of Mxp with 1 median seta and 3 distal setae on a terminal expansion, 2nd segment with 1 seta.

Compl. Ref.:
Pakhomov & McQuaid, 1996 (p.271, abundance, distribution, seabirds); Razouls & al., 2000 (p.343, tab. 2, 5, Appendix); Park & Ferrari, 2009 (p.143, Table 3, fig.2, Appendix 1, biogeography)
NZ: 2

Distribution map of Chiridiella megadactyla by geographical zones
Species Chiridiella megadactyla - Distribution map 3Issued from : E.T. Park & F.D. Ferrari in A selection from Smithsonian at the Poles Contributions to International Polar year. I. Krupnik, M.A. Lang and S.E. Miller, eds., Publs. by Smithsonian Institution Scholarly Press, Washington DC., 2009. [p.167, Fig.2.]
Distribution of selected pelagic calanoids Chiridiella megadactyla of the Southern Ocean and the closest relative in the subarctic region of the Arctic Ocean.
Antarct. (Ross Sea), Subantarct. (off E Campbell Is.)

Type locality: 71°15' S, 176°30' E.
N: 3
(102) F: 4,1; {F: 4,10}
Rem.: Sampling depth (Antarct.) : 0-1000 m.
Last update : 26/07/2018
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 Any use of this site for a publication will be mentioned with the following reference :

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 18, 2024]

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