Chiridius molestus - Species Card - Marine Planktonic Copepods

Chiridius molestus Tanaka, 1957 (F,M)

Taxonomy

Order Calanoida

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Superfamily Clausocalanoidea

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Family Aetideidae

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Genus Chiridius

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Abbreviations or symbols

Synonymy

Chiridius subgracilis Park, 1975 b (p.285, figs.F,M, Rem.); Bradford & Jillett, 1980 (p.23, figs.F,M, fig.73, distribution chart); Mazzocchi & al., 1995 (p.143, figs.F,M, Rem.);
? Chiridius gracilis : A. Scott, 1909 (p.42, figs.F);
Chiridius gracilis : Farran, 1929 (p.208, 229, fig.F); Bradford, 1970 a, figs.M)

References

List of the studied authors

Tanaka, 1957 a (p.53, Descr.M, figs.M); Tanaka & Omori, 1970 (p.118); Markhaseva, 1996 (p.113, Descr.F, figs.F,M); Vives & Shmeleva, 2007 (p.556, figs.M, Rem.)

Figures

Plate 1 issued from : E.L. Markhaseva in Proc. Zool. Inst. RAN, St. Petersburg, 1996, 268. [p.115, Fig.86].
Female (from different specimens and stations).

Plate 2 issued from : E.L. Markhaseva in Proc. Zool. Inst. RAN, St. Petersburg, 1996, 268. [p.116, Fig.87].
Male.

Species Chiridius molestus - Plate 3 of morphological figures

Plate 3 issued from : T. Park in Bull. Mar. Sci., 1975, 25 (2). [p.286, Fig.9]; As Chiridius subgracilis.
Female (from Gulf of Mexico): a, habitus (dorsal); b, c, posterior part of metasome and urosome (dorsal, lateral, respectively); d, exopod of P1; e, P2; f, lateral portion of third exopodal segment of P2 (anterior); g, P3; h, P4. P1-4: legs (anterior).

Species Chiridius molestus - Plate 4 of morphological figures

Plate 4 issued from : T. Park in Bull. Mar. Sci., 1975, 25 (2). [p.227, Fig.10]. As Chiridius subgracilis.
Male (from Gulf of Mexico): a, b, habitus (dorsal, lateral, respectively); c, forehead (lateral); d, distal part of Mxp; e, P1; f, P2; g, third exopodal segment of second leg (anterior); h, fifth pair of legs (posterior). P1-2: legs (anterior).

Species Chiridius molestus - Plate 5 of morphological figures

Plate 5 issued from : J.M. Bradford & J.B. Jillett in Mem. N.Z. Oceanogr. Inst., 86, 1980. [p.24, Fig.12]. As Chiridius subgracilis;
Female: A, habitus (dorsal); B, genital segment (lateral left side); C, P2; D, endopod of P2 (anterior surface).

Male: E, habitus (dorsal); F, last thoracic segment and 1st urosomal segment (lateral left side); G, P5.

Species Chiridius molestus - Plate 6 of morphological figures

Plate 6 issued from : J.M. Bradford in N.Z. Jl Mar. Freshw. Res., 1970, 4 (4). [p.353, Figs 10-12]. As Chiridius gracilis.
Male (off Kaikoura, New Zealand): 10, forehead (ventral view); 11, P5; 12, urosome (dorsal).
Scale bars represent 0.1 mm.

Species Chiridius molestus - Plate 7 of morphological figures

Plate 7 Issued 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.144, Fig.3.24.1]. As Chiridius subgracilis.
Female: A, habitus (dorsal); B, P2; C, exopod 3 of P2.
Nota: Proportional lengths of urosomites and furca 39:23:17:8:13 = 100.

Male: D, habitus (dorsal); E, P5; F, last two distal segments of left P5.
Nota: Proportional lengths of urosomites and furca 18:26:22:20:2:12 = 100.

Species Chiridius molestus - Plate 8 of morphological figures

Plate 8 Issued 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.145, Fig.3.24.2]. As Chiridius subgracilis.
Female (SEM preparation): A, habitus (dorsal); B, urosome (dorsal); C, urosome (ventral); D, P2 and genital somite (ventral); E, exopod 3 of P2.
bars: A-D 0.100 mm; E 0.050 mm.

Species Chiridius molestus - Plate 9 of morphological figures

Plate 9 issued from : O. Tanaka in Publ. Seto Mar. Biol. Lab., 1957, VI (1). [p.54, Fig.33].
Male: a, habitus (dorsal); b, forehead (lateral); c, last thoracic segment (lateral); d, P1; e, P2; f, P5.

Nota: Proportional lengths of urosomites and furca 17:25:23:19:3:13 = 100. A1 (23-segmented) reaches back to the middle of 3rd urosomal segment. Right A1 with segments 20 and 21 fused, 24 incompletely separate from the 25th, proximal segments furnished with well developed aesthetasks.

Plate 10 Chiridius molestus female:
1 - Exopod of Mx1 with 8 setae. Points of last thoracic segment reaching the midlength of the genital segment, usually longer.
2 - Exopodal segment 3 of P2 (often also P3) with bulge near the base of 3rd external spine and excavation near the base of 2nd external spine. Endopodal segment 2 of Md usually with 8 setae.

Plate 11 Chiridius molestus male:
1 - PPoints of last thoracic segment not longer than genital segment.
2 - Right P5 longer than left. Exopodal segments 1 and 2 of P1 with external spines reaching the midlength of the next segment or longer.
3 - Points of last thoracic segment hardly reaching the midlength of urosomal segment 1. Endopodal segment 1 of Mxp with 1 medial seta.

Complementary References

List of the studied authors

Vives, 1982 (p.291); Suarez-Morales & Gasca, 1998 a (p.107); Lapernat, 2000 (tabl.3, 4); Razouls & al., 2000 (p.343, Appendix); Bradford-Grieve, 2003 (p.96, tab.1); Gaard & al., 2008 (p.59, Table 1, N Mid-Atlantic Ridge)

Distribution

NZ: 7

Distribution map of Chiridius molestus by geographical zones

Distribution map of Chiridius molestus for the Zone Indian Ocean

Distribution map of Chiridius molestus and for the Zone Sub-Antarctic

Additional Maps & Charts

Species Chiridius molestus - Distribution map 4

Map 4 Chart of 1996

Species Chiridius molestus - Distribution map 5

Map 5 Issued from : J.M. Bradford & J.B. Jillett in New Zealand Ocean. Inst. Memoir, 86, 1980. [p.90-91, Fig.71].
Distribution of several species of Chiridius in the Tasman Sea and around New Zealand.
Nota: Chiridius subgracilis ( = Chiridius molestus).

Localisations

Geographical glossary

off Mauritania, off Azores, G. of Mexico, Indian, ? Indonesia-Malaysia, Japan (Sagami), Tasman Sea, New Zealand, SE North Island, Straits of Magellan (Pacific and Central area), sub-Antarct. (Pacif. SE).

Type locality: Izu region (Japan)

Quotations

N: 11

Dimensions (mm)

References of the authors concerning dimensions

(35) F: 2,4-2,3; (36) F: 2,72-2,35; M: 2,16-2; (37) F: 2,7-2,3; M: 2,04-1,8; (39) M: 2,04; (113) M: 2,13-2,02; (197) F: 2,32-2,12; M: 1,98-1,8; (201) F: 2,45-2,1; M: 2,1-2; (231) M: 2,03; 2; (313) M: 2; 2,03; {F: 2,10-2,72; M: 1,80-2,16}

Remarks

Mesopelagic.
Sampling depth (sub-Antarct.) : 0-1000 m.
Found for the first time in the Indian Ocean by Markhaseva (1996, p.114) and in the south-eastern part off South America.

Last update : 01/01/2015

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