Ophichthus rutidoderma ( Bleeker, 1852 )

Vo, Quang Van, Hibino, Yusuke & Ho, Hsuan-Ching, 2019, Ophiacantha scissionis Lee & Stöhr & Bae & Shin 2019, sp. nov., Zoological Studies (Zool. Stud.) 58 (43), pp. 1-14 : 9-10

Ophichthus rutidoderma ( Bleeker, 1852) ( Fig. 6 ; Table 4)

Ophisurus rutidoderma Bleeker, 1852: 30 (type locality: Jakarta, Java, Indonesia).

Ophisurus rutidodermatoides Bleeker, 1852: 31 (type locality: Jakarta, Java, Indonesia).

Ophisurus lumbricoides Bleeker, 1852: 32 (locality unknown).

Ophisurus macclellandi Bleeker, 1852: 33 (type locality: Jakarta, Java, Indonesia).

Ophichthus derbyensis Whitley, 1941: 14 , fig. 10 (type locality: Derby, Western Australia).

Specimens examined: OIM-E. 55787, 278 mm TL, from Cần Giờ fishing grounded, Hồ Chí Minh city, caught in a trawl net, at 15‒17 m, 20 April, 2016, by Q.V. Vo.

Description: Body very elongate ( Fig. 6 ), trunk subcircular, tail laterally compressed; body depth at gill openings 42.8 in TL. Head 4.2 in trunk. Head and trunk 3.0 and head 16.7 in TL. Snout rounded, moderately acute, short and sharp when viewed from above; a short groove bisecting underside of snout nearly to tip of upper jaw. Lower jaw included, its tip reaching well beyond base of anterior-nostril tubes. Upper jaw not elongated, rictus immediately behind a vertical line at posterior margin of eye. Eye is small and located anteriorly, 3.3 in upper jaw and 11.1 in head. Anterior nostrils tubular, extending ventrolaterally from snout, reaching below upper lip and beyond tip of chin. Posterior nostrils an elongate opening within upper lip, not visible externally, covered by a flap that extends below edge of mouth and lacks a vertical slit. Dorsal-fin origin well behind pectoral fin about smaller than a head length into trunk length. Median fins low but obvious, ending a little more than eye diameter before bluntly pointed and laterally compressed tail tip. Pectoral fins elongate.

Head pores small but apparent. Single median interorbital and temporal pores. Supraorbital pores 1 + 4, infraorbital pores 4 + 2, lower jaw pores 5, preopercular pores 2, supratemporal pores 3. Lateral-line pores apparent; 9 on head, in an arching sequence, 15 before dorsal-fin origin; 64 before anus, 190 in total, the last ca. 2 eye diameters before tail tip.

Teeth small, conical, slightly recurved; uniserial in upper jaw, biserial on vomer and biserial anteriorly and uniserial posteriorly on lower jaw. An intermaxillary rosette of 4, followed by a gap, then followed by two rows of vomerine teeth with 17 teeth. Maxillary tooth separated by a moderate gap, with 16 or 17 small teeth. Mandibular teeth mostly uniserial, with an outer row of 5 or 6 teeth anteriorly, and an inner row with 15‒16 descending in size to become very small posteriorly.

Coloration: Colour in ethanol uniformly dark brown; throat, snout and chin slightly darker; anterior nostrils, inside of mouth, anal region and peritoneum pale. Median and pectoral fins pale.

Figures

Fig. 6. Ophichthus rutidoderma (Bleeker, 1852), OIM-E.55787, 278 mm TL; (a) Lateral view of head (a) preserved in formalin 10%, (b) vertebral column of preanal region.