Eudorella hwanghaensis Hong & Park, 1999

Akiyama, Tadashi & Gamô, Sigeo, 2012, The cumacean Genus Eudorella (Crustacea: Peracarida) from Japanese Waters, Northwest Pacific, and E. suluensis sp. nov. from the Sulu Sea, Indo-West Pacific, Zootaxa 3319, pp. 1-56 : 38-39

Eudorella hwanghaensis Hong & Park, 1999

( Fig. 26 )

Eudorella hwanghaensis Hong & Park, 1999: 446 –451, figs. 1–4.

Material examined. 10 ovigerous females, 5.4–6.6 mm (7 specimens dissected), 5 preparatory females, 5.4–6.3 mm, 2 adult males, dissected, 1 subadult male, 5.4 mm (NSMT-Cr 22138), Enshu Nada, 34°33ˏN, 138°03ˏE – 34°32ˏN, 138°03ˏE, 240–260 m (KT-02-5, St. EN-2-3) 26 May 2002; 1 ovigerous female, 5.5 mm, dissected (NSMT-Cr 22139), Enshu Nada, 34°36ˏN, 137°59ˏE, 116–155m, 27 May, 2002 (KT-02-5, St. EN-4-2); 1 ovigerous female, 5.1 mm, 1 preparatory female, 5.2 mm (NSMT-Cr 22140), 34°59.11ˏN, 140°036.29ˏE, 104 m (KT-03-17, St. KG-1), 17 November 2003; 1 ovigerous female, 5.9 mm, 5 preparatory females, 4.7–6.0 mm, 3 adult males, 5 subadult males, 5.4 mm (NSMT-Cr 22141), 34°58.19ˏN, 140°05.19ˏE, 169–186 m (KT-03-17, St. KG-2), 17 November 2003; 1 ovigerous female, 5.9 mm, 1 adult male (damaged) (NSMT-Cr 22142), 34°57.93ˏN, 140°06.57ˏE, 260–278 m (KT-03-17, St. KG-3) 17 November 2003; 1 ovigerous female, 5.2 mm, dissected (NSMT-Cr 22143), 29°40.97ˏN, 127°44.40ˏE, 596 m (N275, St. P2) 30 November 2008.

Remarks. Japanese specimens agree well with the description of specimens from the Yellow Sea ( Hong & Park, 1999). Noteworthy morphological characters of females are: (1) lower end of antennal notch slightly behind frontal margin of carapace, rather near foremost tooth on inferior margin; (2) 1st article of antenna 1 main flagellum with 3–5 simple setae on outer margin; (3) antenna 1 main flagellum with 3–5 (4.27±0.66, N=24) simple setae on outer margin; (4) antenna 2 with 3–5 setae (4.0±0.50, N=9) on lower margin ( Fig. 26 A); (5) basis with maxilliped 2 with many setae on inner margin, as illustrated by Hong & Park (1999); and (6) basis of pereopod 1 with 1– 3 (1.58±0.47, N=25) very robust setae on the ventral surface.

The distal three articles of pereopod 3 of adult males show remarkable secondary sexual characters ( Fig. 26 B), which are currently unique in the cumacea . (1) The carpus has two stiff, curved setae distally and 3 unusually long setae on the lateral margin. (2) The propodus has a stiff, curved seta on the lateral margin. (3) The terminal seta on the dactylus is stiff, slightly curved. In appearance, this structure looks like a small chela, which is directed forward or slightly in toward of the body, whereas the normal pereopod 3 of Eudorella is directed away from the body. The complex morphology of this appendage was identical in the six specimens examined. Subadult males have normally shaped pereopods 3 ( Fig. 26 D). Adult males may use this leg for clasping females, or for some other purpose, when they mate.

Distribution. Yellow Sea, Pacific coast of Honshu Island, off Kyushu Island, East China Sea, 59– 596 m. The depth range in Japan is deeper than in Korean waters, where the specimens were collected from 59–93 m ( Hong & Park 1999): Japanese specimens were collected from about 100– 300m. This species is probably an inhabitant of the continental shelf, or uppermost region of the continental slope.

Figures

FIGURE 26. Eudorella hwanghaensis Hong and Park, 1999. A, antenna 2 of ovigerous female; B, distal 3 articles of pereopod 3 of adult male; C, uropod and pleonite 6 of adult male. D, distal 3 articles of pereopod 3 of subadult male.