Ventrifossa rhipidodorsalis Okamura, 1984

Ventrifossa rhipidodorsalis Okamura in Okamura and Kitajima, 1984:205 (Okinawa Trough, 28°42.0ʹN, 127°09.0ʹE, 500–535 m (holotype, BSKU 27695; 23 paratypes, Okinawa Trough and Tosa Bay, 500–650 m [but 1 spec. at 220 m]).— Okamura in Masuda et al., 1984:94 (compiled).— Iwamoto and Williams, 1999:228 (mentioned).— Chiou et al., 2004b:48, fig.22 (13 spec.; Nanfangao, Taiwan [NET]).

? Ventrifossa nigrodorsalis: Okamura in Okamura et al., 1982:147, 348, fig. 90 (2 spec.; BSKU 29495, later identified as V. rhipidodorsalis by Okamura in Okamura and Kitajima, 1984: fig. 146C).

MATERIAL EXAMINED (70 Taiwan spec.).— NET: ASIZP 61246 (1, 170 TL), Nan-fang-ao; ASIZP 61247 (12, 142–168 TL), Nan-fang-ao; ASIZP 62331 (2, 126+-162+ TL), Fong-kang, 200 m; ASIZP 64236 (3, 110+-215 TL) and CAS 224885 (ex. ASIZP 64236) (2, 121+~161 TL), CP 234, 547 m; ASIZP 65549 (1, 160+ TL), CP 124, 1129–1165 m; ASIZP 70231 (2, 109–113 TL), Da-xi; ASIZP 70248 (9, 98–180 TL), Nan-fang-ao; ASIZP 70250 (1, 125 TL), Da-xi; ASIZP 70685 (1, 40 HL), Da-xi; ASIZP 70733 (1, 196 TL), Da-xi. SWT: ASIZP 62388 (1, 181 TL), Dong-gang, 300 m; ASIZP 66322 (1, 153 TL), Dong-gang. SCS: ASIZP 65521 (11, 100–142 TL) and ASIZP 65592 (18, 105–165 TL), CD 136, 998– 1211 m; ASIZP 65588 (3, 140–155 TL), CD 141, 985– 1110 m. SET: ASIZP 66104 (1, 65 HL, 285+ TL), CP 299, 799 m. Other specimens: BSKU 27695 (holotype) and six paratypes, BSKU 27123, 27191, 27660, 27696, 27861, 27865, Okinawa Trough. CAS 88668 (5, 51.6–58.7 HL, 233+-312+ TL), Philippines, off se coast Luzon; 14˚50.46ʹN, 123˚17.30ʹE, 760–770 m; R / V Fishery Researcher I sta. TFRI-Ph1–12–95, 27 Sep. 1995.

DISTINGUISHING FEATURES.— 1D II,10–12; P i19–i23; V 9–10; total GR-I (lateral/mesial) 10–13/15–17 total, (lateral/mesial) GR-II 14–17/(13)15–17; scale rows below midbase 1D 5.5–7.5, below 2D 7–8.5; lateral line scales over distance equal to predorsal length 36–43. Snout length 25–32% HL; preoral length 11–15%; internasal 18–23%; interorbital 21–27%; orbit 26–34%; postorbital 42–48%; orbit to preopercle (38) 41–44%; suborbital 11–14%; upper jaw (39) 42–47%; barbel (16) 19–26%; outer gill slit 22–28%; 1D-2D interspace 45–62%. Body moderately deep and compressed; snout low, blunt in adults, somewhat more pointed and protruding in young; suborbital area gently rounded. Body scales covered with small, slender, needle-like spinules in wide chevron-like rows; an area of spinuleless scales along and behind 1D base. Color in alcohol overall dark, with faint silvery reflections along sides of head and trunk; bluish-black over abdomen and chest; 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, suparnarial ridges, and a V-shaped stripe joined at apex to black nape stripe before 1D; 1D black except distal third or less white, base dusky to pale; V black, P dusky but base black with bulk of lateral face of base silvery, A dark dusky overall but with narrow black distal margin anteriorly. Lips, mouth, jaws, and gill cavity as in others of genus. Attains about 33 cm TL.

DISTRIBUTION.— From s. Japan to sw. Taiwan (SCS) in 400–1211 m.

REMARKS.— Among the Taiwanese grenadiers, V. rhipidodorsalis is most similar to V. nigrodorsalis, but that species has 8 or 9 V rays (cf. 9 or 10), overall paler coloration; paler, more silvery sides; slightly sharper, more protruding snout; generally narrower black streak on 1D; and shorter upper jaw (37–41% HL). In its overall dark color and V count of 9–10, it resembles V. macroptera, but that species has a smooth 1D spinous ray and differences in dentition. Another species with a black streak across the 1D is V. longibarbata, but that species has slightly lower average number of V rays (8–9), much longer barbel (28–39% HL cf. 19–26%), slightly longer preoral length (16–17% cf. 11–15%), and somewhat fewer scale rows below 2D (5.0–6.5 cf. 7.0–8.5).