Ventrifossa nigrodorsalis Gilbert and Hubbs, 1920

Iwamoto, Tomio, Nakayama, Naohide, Shao, Kwang-Tsao & Table, Hsuan-Ching Ho, 2015, Synopsis of the Grenadier Fishes (Gadiformes; Teleostei) of Taiwan, Proceedings of the California Academy of Sciences 62 (3), pp. 31-126 : 114-115

Ventrifossa nigrodorsalis Gilbert and Hubbs, 1920

Ventrifossa nigrodorsalis Gilbert and Hubbs, 1920:546 (holotype, USNM 83627; n. coast Mindanao, Philippines, 391 m; 168 paratypes from Formosa [ Taiwan], Philippines, and East Indies, 290–868 m). Iwamoto, 1990:307–309, fig. 690 (descr.).— Iwamoto and Merrett, 1997:559 ( New Caledonia and vicinity).— Iwamoto and Williams, 1999:224–225, 228, fig. 54 (descr., e. and w. Australia).— Iwamoto and Graham, 2001:497–498, fig. 112 (descr., se. Australia, 300–790 m).— Chiou et al., 2004b:47 (listed, Taiwan, Table 1 ).

MATERIAL EXAMINED (3 Taiwan spec.).— NET: ASIZP 66903 (1, 197 TL), CP 248, 536 m; ASIZP 70715 (1, 188 TL), Da-xi. SCS: ASIZP 57974 (1, 183+ TL), Tong-sa Islands. Other specimens: USNM 8362 (holotype, 41.5 HL, 214 TL), Philippines, Mindanao Sea; 8˚37’37ʺN, 124˚35ʹE, 391 m, Albatross sta. 5502, 4 Aug. 1909 . USNM 149302 (paratypes, 4, 32.3–36.0 HL, 125+-195+ TL) , same data as for holotype; CAS 64574 (5, 30–9–36.6 HL, 499+-193+ TL), SCS off Vietnam; 15˚40’00ʺN, 109˚47ʹE, 479 m. CAS 221057 (38.5 HL, 210+ TL), Philippines, e. coast Luzon , 14˚41’04ʺN, 123˚24’07ʺE, 435–451 m, Fishery Researcher I, field no. TI95–12 , 27 Sept. 1995 .

DISTINGUISHING FEATURES.— 1D II,9–10; P i19–i23; V 8–9; total GR-I (lateral/mesial) 9–13/13–15, GR-II 13–14 /13–14; scale rows below 1D 8–9, below 2D 7–9; lateral line scales over distance equal to predorsal length 36–43. Snout length 29–30% HL; preoral length 19–21%; internasal 22–23%; interorbital 23–28%; orbit 28–34%; postorbital 42–44%; orbit to preopercle 39–42%; suborbital 13–16%; upper jaw 37–41%; barbel 17–26%; outer gill slit 21–25%; 1D-2D interspace 39–66%. Body and head moderately deep and compressed, nape somewhat elevated; snout slightly protruding beyond mouth, acutely pointed in lateral view, broadly obtuse in dorsal view. Body scales covered with small, needle-like spinules in wide chevron-like rows; small area of spinuleless scales along and behind 1D base. Color in alcohol grayish-brown dorsally on trunk, becoming paler along 2D base to form a dorsolateral stripe on tail; top of head and snout pale, integument translucent; faint silvery reflections along sides of head and ventrally on trunk and tail; underlying silvery pigmentation abdomen and chest bluish-black, tail pale with light peppering; gill cover and gill membranes mostly black; mouth and gill cavities pale, but dark in gullet; black margins on suborbital shelf, leading edge of snout, and supranarial ridges; 1D with black blotch or blackish over middle third or so of fin but pale distally and along base; V black, sometimes paler distally and near base; P and A dusky, but base of P black with lateral surface mostly silvery. Lips, jaws, and gill cavity as in others of genus. Attains about 25 cm TL in Taiwan region, possibly more elsewhere.

DISTRIBUTION.— Known from off Australia, New Caledonia region, and Indonesia n. to the Philippines, Taiwan ( NET), and the South China Sea.

REMARKS.— Okamura (in Okamura et al. 1982:147, 348, fig. 90) initially recorded this species from two specimens collected in Tosa Bay. He later ( Okamura et al. 1984) treated those specimens as representatives of his new species V. rhipidodorsalis , and used the photograph of one of the specimens (fig. 146C; BSKU 29495, 172 mm TL) to illustrate another example of the new species. Ventrifossa nigrodorsalis is an apparently broadly distributed species abundant in the Philippines, Indonesia, and the warm-water regions of Australia, as well as the sw. Pacific off New Caledonia, Vanuatu, and near regions, but it was scarce off Taiwan. Characters that have been used to distinguish species of Ventrifossa are often subtle and dependent on well-preserved specimens to observe. The existence of seemingly widely scattered populations of V. nigrodorsalis heighten the possibility that other species lie hidden under the cloak of that species name as currently circumscribed, and they may be unveiled after closer study of more specimens. The description provided above is from specimens collected off Taiwan, the South China Sea, and the Philippines in the Mindanao Sea between Mindanao and Cebu.