The cumacean Genus Eudorella (Crustacea: Peracarida) from Japanese Waters, Northwest Pacific, and E. suluensis sp. nov. from the Sulu Sea, Indo-West Pacific
Author
Akiyama, Tadashi
Author
Gamô, Sigeo
text
Zootaxa
2012
3319
1
56
journal article
10.5281/zenodo.213431
528fecdb-40d6-44ed-bb62-e706cbe3bda6
1175-5326
213431
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
.
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.
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.