 |
| Obliquogobius eptactis Fujiwara, Psomadakis, Swe & Motomura, 2021 |
Abstract
Obliquogobius eptactis, new species (Teleostei: Gobiidae) is described on the basis of four specimens (40.7–50.1 mm in standard length) collected by the R/V Dr. Fridtjof Nansen from the Andaman Sea, off Myanmar, in depths of 181–184 m. The new species is characterised by the following combination of characters: 2nd dorsalfin rays I, 9 or 10; head somewhat large, length 32.9–34.4% of SL; lateral surface of nape scaled; postorbital pore G present (in anterior oculoscapular canal); gill opening relatively narrow, anteroventral point extending slightly forward to vertical level of preopercle margin; caudal fin dorsoventrally asymmetrical, rays in upper half much longer than those in lower half, giving obliquely pointed appearance; seven bright yellow bars (pale whitish in preserved specimens) on body, two under 1st dorsal-fin base, remainder under 2nd dorsal fin (from origin) and on caudal peduncle; dorsal fins pale brown with bright yellow barred pattern; 1st dorsal fin without broad black margin; pectoral fin bright yellow; three bright yellow vertical bars on upper part of caudal fin; distinct black spot on centre of caudal-fin base absent. Although the new species is similar to Obliquogobius yamadai Shibukawa & Aonuma, 2007, the former can be distinguished from the latter by having seven bright yellow bars on the body [vs. five bars (rarely six, including indistinct partial bar located above anus) in O. yamadai], a bright yellow barred pattern on the dorsal fins (vs. 1st and 2nd dorsal fins lacking barred patterns: 1st dorsal fin with distinct broad black margin, 2nd dorsal fin generally faint yellow), bright yellow pectoral fins (vs. translucent white or faint yellow), no distinct small black spot centrally on the caudal-fin base [vs. a small black spot (variable in size) with following indistinct yellow partial bar present], three bright yellow irregular vertical bars restricted to upper part of caudal fin (vs. three longitudinal yellow stripes on entire fin; stripes faded out soon after capture), and larger head, length 32.9–33.3 (vs. 28.3–32.2) and 34.4 (vs. 29.1–33.5) % of SL in males and females, respectively.
Key words. Obliquogobius eptactis, Obliquogobius yamadai, deepwater goby, R/V Dr. Fridtjof Nansen, trawl surveys, Myanmar, Indian Ocean
 |
| Fresh colouration of Obliquogobius eptactis, new species. A, B, SAIAB208554, male, 50.1 mm SL; C, SAIAB 208473, male, 47.0 mm SL; D, SAIAB 208484, female, 40.7 mm SL. A, C, D, lateral views; B, dorsal view. |
Obliquogobius eptactis, new species
[New English name: Seven-striped deepwater goby]
Diagnosis. A species of Obliquogobius (Fig. 1) distinguished
from other members of the genus by the following
combination of characters: 2nd dorsal-fin rays I, 9 or 10;
head somewhat large, length 32.9–34.4% of SL; lateral
surface of nape scaled; postorbital pore G present (in
anterior oculoscapular canal); gill opening relatively
narrow, anteroventral point extending slightly forward to
vertical level of preopercle margin; caudal fin asymmetrical
dorsoventrally, rays in upper half much longer than those
in lower half, giving obliquely pointed appearance; seven
bright yellow (pale whitish in preserved specimens) bars on
body, two located under 1st dorsal-fin base, remainder under
2nd dorsal-fin (from origin) and on caudal peduncle; dorsal
fins pale brown with bright yellow barred pattern; 1st dorsal
fin without broad black margin; pectoral fin bright yellow;
three bright yellow vertical bars on upper part of caudal
fin; distinct black spot on centre of caudal-fin base absent.
Distribution. Currently known only from four specimens
trawled between 181–184 m off the Myeik Archipelago,
Andaman Sea.
Etymology. The specific name “eptactis”, a combination
of the New Greek “epta” and “aktis”, means “seven light
rays”, in reference to the seven characteristic yellow bars
on the body.
Kyoji Fujiwara, Peter N. Psomadakis, Thet Yu Yu Swe and Hiroyuki Motomura. 2021. Description of A New Species of Obliquogobius (Teleostei: Gobiidae) from the Andaman Sea (northeastern Indian Ocean). RAFFLES BULLETIN OF ZOOLOGY. 69; 541–547. DOI: 10.26107/RBZ-2021-0070
