Bathygadus furvescens Alcock, 1894

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 : 38

Bathygadus furvescens Alcock, 1894

Figures 1A–B .

Bathygadus furvescens Alcock, 1894:128 (holotype ZSI F13047, “ 20.5 inches ” [ca. 52 cm]; off Maldives, Investigator sta. 150; 719 fm [1,315 m]).— Gilbert and Hubbs, 1920:388–391 (descr.; 5 spec., 5 loc., Philippine and Indonesia; 565–976 fm [1033–1785 m]).— Iwamoto and Merrett, 1997:479 (validated position of species in Bathygadus ).— Iwamoto and Graham, 2001:422–423, fig. 17 (descr., 10 spec., se. coast Australia, “depths between 1,000 and 1, 240 m ”).— Shao et al., 2008: table 2 (2 spec., SET, first record for Taiwan).

MATERIAL EXAMINED (10 spec).— SET: ASIZP 65510 (1, 91.8 HL, 475+ TL); CP 127, 1263– 1268 m. Others questionably assigned to species, but with black head and abdomen, lacking paler areas on head : SET: ASIZP 66938 (1, 475 TL); CP 127, 1263–1268 m . SWT: ASIZP 66115 (1, 100 HL, 450 TL); CD 322, 1098 m ; ASIZP 70215 (1, 345 TL) ; ASIZP 63788 (4, 118+-380+ TL); CD 192, 1305 m ; ASIZP 65530 (2, 280–335 TL); CD 134, 736– 1040 m .

DISTINGUISHING FEATURES.— A species of Bathygadus with no scales on gular membrane; chin barbel absent; dorsal profile slightly elevated over nape; 1D II,8–10; P i15–i19; V 8–9; gill-rakers outer arch (5–6) + (18–20); pyl. caeca 20–22. Interorbital width 26–30% HL; orbit diameter 21–23%; suborbital width 14–15%; postorbital length 51–55%; distance orbit to preopercle 48–50%; length upper jaw 56–59%; length P 61–81%; length V 67–83%; length longest gill-raker 13–15%. Fins well developed; outer V ray elongated and distally filamentous. Flesh and head bones relatively firm. Fins black to dark dusky. (After Iwamoto and Graham [2001:479] except for lengths of postorbital and longest gill-raker, the ranges of these were extended by our specimens.)

DISTRIBUTION.— Recorded from Maldives, Indonesia, Philippines, se. Australia, and now off Taiwan, in depths between approximately 1000 m and 1800 m.

REMARKS.— Howes and Crimmen (1990:195) treated the species as a member of Gadomus based on a specimen they erroneously considered a syntype, but which not only was non-type material but also a species different from the holotype (see Iwamoto and Merrett 1997:479). The large Taiwan specimen was similar in most mensurable and count characters to the specimens we called B. antrodes . However, its head bones were stouter, integument notably tougher, with scale pockets well developed, color overall paler, the interorbital width slightly narrower (27–28% HL), and none of the fin rays longer than the head. The specimen agreed in these respects with B. furvescens as circumscribed by Iwamoto and Graham (2001:422–423) and represents the first record of the species from Taiwan waters.

Figures

FIGURE 1. Bathygadus furvescens Alcock, 1894. A. ASIZP 65510, 475+ mm TL, preserved. B. ASIZP 63788, 1 of 4, 380+ mm TL, preserved.