Bradyidius similis - Species Card - Marine Planktonic Copepods

Bradyidius similis Sars, 1902 (F,M)

Taxonomy

Order Calanoida

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Superfamily Clausocalanoidea

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Family Aetideidae

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Genus Bradyidius

details list species for this Genus

Abbreviations or symbols

Synonymy

? Bradyanus armatus Vanhöffen, 1897 a (p.280, figs.); Mrazek, 1902 (p.521);
Undinopsis similis Sars,1902 (1903) (p.34, figs.F,M); Sars, 1925 (p.44); Rose, 1933 a (p.92, figs.F,M); Kovalev & Schmeleva, 1982 (p.83); Mikhailovsky, 1986 (p.83, Table 1, ecological modelling); Gaard & al., 2008 (p.59, Table1, N Atlantic Mid-Ridge);
Undinopsis armatus : Vanhöffen, 1907 (p.517, Pl.21: fig.24, Pl.22: figs.28-30); With, 1915 (p.88, Rem.)

References

List of the studied authors

Vervoort, 1952 b (n°43, p.3, figs.F,M); ? C.B. Wilson, 1950 (p.173, fig.M); Park, 1966 (p.810, Rem.F,M); Bradford, 1976 a (p.6: Rem.); Shih & al., 1981 (p.1079, figs. F,M, juv.); Gardner & Szabo, 1982 (p.208, figs.F,M); Othman & Greenwood, 1987 (p.1137); Markhaseva, 1996 (p.79, figs.F,M); G. Harding, 2004 (p.42, figs.F,M); Yamaguchi & al., 2005 (p.835, Tabl. VIII)

Figures

Plate 1 issued from : E.L. Markhaseva in Trudy Zool. Inst. RAN, St. Petersburg, 1996, 268. [p.83, Fig.60].
Female. P.md: mandibular palp; R: rostrum (anterior).

Nota: Cephalothorax 3.2-3.3 times longer than urosome.
Rostrum with slightly divergent rami (in some specimens nearly non divergent).
Points of last thoracic segment reaching or exceeding the midlength of genital segment.
A1 24-segmented, reaching nearly the end of cephalothorax.
Mx1 gnathobase with 4 posterior setae; endopd with 15-17 setae; 2nd internal lobe of Mx1 with 4 setae (5 for Shih & al., 1981).

Species Bradyidius similis - Plate 2 of morphological figures

Plate 2 issued from : E.L. Markhaseva in Trudy Zool. Inst. RAN, St. Petersburg, 1996, 268. [p.84, Fig.61].
Male. Ce: forehead (lateral); R: rostrum (anterior).

Nota: Right A1 23-segmented; left 24-segmented, reaching urosomal segment 4; penultimate segment of right A1 with group of denticles.
Oral parts rudimentary compared to those of females.
Exopod of left P5 2-segmentd; right P5 3-segmented.

Species Bradyidius similis - Plate 3 of morphological figures

Plate 3 issued from : G.O. Sars in An Account of the Crustacea of Norway. Vol. IV. Copepoda Calanoida. Published by the Bergen Museum, 1903. [Pl.XXI]. As Undinopsis similis.
Female & Male.
pr = corner of the last thoracic segment; M = Md (mandibular palp).

Species Bradyidius similis - Plate 4 of morphological figures

Plate 4 issued from : C.-t. Shih, L. Rainville & D.C Maclellan inCan. J. Zool., 1981, 59 (6). [p.1089, Figs.79-92].
Female (from Saguenay fjord and adjacent waters of the St. Lawrence River): 79-80, habitus (dorsal and lateral, respectively); 81, rostrum (frontal view); 82, same (lateral); 83, A1; 84, A2; 85, Md and enlarged distal part of gnathobase); 86, Mx1; 87, Mx2; 88, Mxp; 89-92, P1 to P4.
Scale A for appendages; scale B for figs 79-80.

Species Bradyidius similis - Plate 5 of morphological figures

Plate 5 issued from : C.-t. Shih, L. Rainville & D.C Maclellan inCan. J. Zool., 1981, 59 (6). [p.1090, Figs.93-108].
Male: 93-94, habitus (dorsal and lateral, respectively); 95, rostrum ( frontal view); 96, same (lateral); 97, anal somite and caudal rami (dorsal); 98, A1; 99, A2; 100, Md (gnathobase entirely degenerated); 101, Mx1; 102, Mx2; 103, Mxp; 104-108, P1 to P5.
Scale A for appendages and rostrum; B for figs.93-94 and 97.

Nota: left A1 24-segmented; right 23-segmented (segments 8-9, 20-21 fused), reaching nearly to posterior margin of 3rd thoracic segment. 1st thoracic segment completely fused with cephalosome. A2 exopod slightly longer than endopod. Md exopod 4-segmented with 3 terminal setae; gnathobase degenerated. Mx1 reduced in size, segmentation and armature; 1st outer lobe with 5 setae; exopod not reduced, with 10 setae; endopod 2-segmented with 4 and 5 setae respectively; 1st inner lobe degenerated, 2nd inner lobe reduced, with 3 terminal setae and a few spinules on medial and lateral margins, 3rd inner lobe reduced to a small process without setae. Mx2 reduced to a narrow lobulated structure with 2 small setae at distal end. P1 to P4 similar to those of female. Urosome 5-segmented, anal somite very short.

Plate 6 issued from : G. Harding in Key to the adullt pelagic calanoid copepods found over the continental shelf of the Canadian Atlantic coast. Bedford Inst. Oceanogr., Dartmouth, Nova Scotia, 2004. [p.42].
Female & Male.

Female with rostrum deeply bifurcate; last thoracic segment with spines thick at base.

Plate 7 Bradyidius similis female: 1 - Rostrum with divergent rami.
2 - Points of last thoracic segment not reaching posterior border of genital segment. Exopodal segment 2 of A2 with 2 setae. Exopodal segment 1 of P1 with external spine not reaching the base of external spine of segment 2.
3 - Posterior corners of last thoracic segment nondiverging.
4 - Rostral rami sligtly divergent (compare with B. saanichi), acute angle in their base.

Plate 8 Bradyidius similis male: 1 - P5 biramous.
2 - Endopod of left P5 1-segmented.
3 - Points of last thoracic segment reaching or even exceeding posterior urosomal segment 1.

Complementary References

List of the studied authors

Maclellan D.C., 1967 (p.101, 102: occurrence); Shih & al., 1971 (p.32, 143); Tremblay & Anderson, 1984 (p.3, Rem.); Shih & Marhue, 1991 (tab.3); Sirenko & al., 1996 (p.345); Markhaseva, 1998 (p.250, Fig.2); Bradford-Grieve, 2004 (p.283); Blachowiak-Samolyk & al., 2006 (p.101, tab.1); Blachowiak-Samolyk & al., 2008 (p.2210, Table 3, as similles, biomass); Hop & al., 2006 (p.182, Table 4); Galbraith, 2009 (pers. comm.); Dvoretsky & Dvoretsky, 2010 (p.991, Table 2); Kosobokova & al, 2011 (p.29, Table 2, 3, Rem.: Arctic Basins)

Distribution

NZ: 7 + 2 doubtful

Distribution map of Bradyidius similis by geographical zones

Distribution map of Bradyidius similis for the Zone Mediterranean Sea, Black Sea

Localisations

Geographical glossary

North Sea, Norway, Barents Sea, Greenland, Kongsfjorden, Spitzbergen, Laptev Sea, Nansen Basin, NE Atlant., Azores, E Medit. (Ionian Sea), G. of Maine, Nova Scotia, G. of St. Lawrence, Saguenay Fjord, Baie des Chaleurs, Ameralik & Godthaab fjords (W Greenland), Bering Sea, Okhotsk Sea, Queen Charlotte Is., British Columbia, ? Philippines (in C. B. Wilson, 1950)

Quotations

N: 22

Dimensions (mm)

References of the authors concerning dimensions

(37) F: 3,24-2,84; M: 2,77-2,4; (65) F: 3; M: 2,4; {F: 2,84-3,24; M: 2,40-2,77}

Remarks

neritic, hyperbenthic, mesopelagic.
The identification from the Philippines seems doubtful and needs confirmation.
Its observation in the Mediterranean Sea needs confirmation.

Last update : 12/11/2018

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