Eviota storthynx ( Rofen, 1959 )

Shen, Kang-Ning, Hung, Tsang-Hsieh & Chen, I-Shiung, 2024, A new species and two newly recorded species of Eviota (Teleostei: Gobiidae) from Taiwan, Zootaxa 5550 (1), pp. 32-40 : 36-38

Eviota storthynx ( Rofen, 1959)

( Fig. 3 )

(DZmDzñṱ)

Eviotops storthynx Rofen, 1959: 237 . (Bungau, Sulu Province, Philippines)

Eviota storthynx Lachner & Karnella, 1980: 57 ; Yoshino & Shimada in Masuda et al. 1984: 244.

Material examined

NTOUP-2023-08-112, 11.4 mm SL, Coll. I-S. Chen. Aug. 18, 2023, Nan-fang-ao, Su-ao , Ilan County, Taiwan .

Diagnosis

The species can be well distinguished from other congeners by the following combination of features: (1) second dorsal fin I/8, anal fin I/7, pectoral fin 15; (2) longitudinal scale rows 25; (3) typical head canal pattern type 2; (4) fifth pelvic fin rays about 10% of fourth pelvic fin rays; (5) mouth moderate large, extending to anterior vertical of pupil; and (6) specific coloration: each scale pockets with anterior yellowish to brownish curve; ventral profile after anus with 7 main blackish brown spots, snout with pointed blackish brown mark; a postocular black spot present; mouth orange; pectoral fin base with an orange bar above and a median white bar; first dorsal fin with red spots in distal spinous rays; caudal fin grayish with 4–5 vertical rows of grayish black lines; caudal fin base with three black to brown spots or short lines.

Description

Body very slender and rather compressed. Eye large and snout rather blunt and short. Gill-opening restricted, extending just to anterior edge of opercle. Interorbital region very narrow. Mouth moderately large, extending to anterior margin of pupil. Vertebral count 26.

Body morphometric proportions from the specimen as: head length 29.6%; snout to origin of first dorsal fin 37.9%; snout to origin of second dorsal fin 56.2%; snout to origin of anal fin 61.2%; body depth at anal fin origin 20.9%; caudal peduncle length 24.1%; and caudal peduncle depth 14.6%, which all above in standard length. Eye diameter 30.6%; postorbital length 53.1%; snout length 18.4%; and upper jaw length 31.4%, which all above in head length.

Fins. —D1 VI, D2 I/8; P 15; A I/7; VI/5+I/5. First dorsal fin with anterior two rays elongate in male. Rear of second dorsal fin tip not extending toward vertical of caudal fin base in current male. Fifth pelvic fin ray very short, about 10% of fourth rays.

No frenum, no connecting membrane between 2 pelvic fins.

Scales.—LR 25, TR 8, PreD 0. Body with rather large ctenoid scales. Predorsal region entirely naked. Head, opercle and nape naked.

Head lateral-line system. Same to typical head canal type 2 (see Lachner & Karnella, 1980).

Coloration in fresh material

Body and head translucent with creamy yellow background. Each scale pockets with anterior yellowish to brownish curve. Ventral profile after anus with 7 main blackish brown spots. Snout with pointed blackish brown mark.

Anterior nostril brown. Eye with 7 main brown red regions. Nape with a longitudinal brown stripe. Opercle with horizontal reddish brown stripe. A postocular black spot present. Mouth orange. Chin red to pinkish. Pectoral fin base with an orange bar above and a median white bar. First dorsal fin with red spots in distal spinous rays. Basal region of first dorsal fin grayish. Second dorsal fin grayish with few red to brown spots. Caudal fin grayish with 4–5 vertical rows of grayish black lines. Caudal fin base with three black to brown spots or lines. Anal fin grayish. Pelvic fin translucent.

Distribution

The species can be found in Japan (Ryukyu and Ogasawara Islands), Micronesia ( Palau and Yap), Hong Kong, northern Vietnam, Philippines, Indonesia (Java and Kalimantan to West Papua), and Western Australia ( Greenfield & Wintterbottom, 2016).

The current collection is the new record from Taiwan. This rare species could potentially be found in other regions of Taiwan.

Figures

FIGURE 3. Eviota storthynx (Rofen, 1959), 11.4 mm SL, male, Su-ao, Ilan County, Taiwan.