Bathygadus antrodes (Jordan & Starks, 1904)

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 : 37-38

Bathygadus antrodes ( Jordan and Gilbert, 1904)

Melanobranchus antrodes Jordan and Gilbert, 1904:606–607, pl. 4, fig. 7. (holotype: USNM 50932 , 265 TL, Sagami Bay , Japan, 501–749 fm [916–1,370 m], Albatross sta. 3696; other spec. from Sagami and Suruga bays, 480–677 fm [878–1238 m]).

Bathygadus antrodes : Gilbert and Hubbs, 1916:149–150 (16 spec., 9 local. off Honshu I., Japan; 440–712 fm [805–1,302 m]).— Okamura, 1970:30–33, pl. XI, text-fig. 16 (descr.; 15 spec.; Japan); Okamura, 1984:197, 356, fig. 138 (descr. in Japanese and English; 4 spec.; s. Japan, Okinawa Trough, 792– 1,200 m).— Howes and Crimmen, 1990:191 ( USNM spec.; s. Japan). Sazonov 1994:100–101, fig. 1 (5 spec., Nintoku Seamount [on Emperor Seamounts chain]; 1120–1160 m).— Chiou et al., 2004b:39. fig. 5 (2 spec., NET; one spec. we currently re-identify as B. garretti ).— Shao et al., 2008: table 2 (19 spec., NET, SWT, SET, SCS).

MATERIAL EXAMINED (7 spec.).— NET: ASIZP 61225 (1, 635 TL); Da-xi . SCS: ASIZP 65515 (1, 66.8 HL, 350 TL); CD 322, 1098 m ; ASIZP 65633 (2, 150–375+ TL); CD 229, 880– 1062 m . SET: ASIZ 67033 (1, 78.1 HL, 367+ TL); CP 350, 1148 m ; ASIZP 66100 (1, 62 HL, 310 TL); CD 322, 1098 m ; ASIZP 66110 (1, 73.1 HL, 377+ TL); CD 322, 1098 m .

DISTINGUISHING FEATURES.— A species of Bathygadus with no scales on gular membrane; chin barbel absent; dorsal profile behind head elevated, nape somewhat humpbacked; 1D II7–9; P i14–i18; V 8–9; GR 5–6+18–20; pyl. caeca 10–18*; interorbital width 31–36% HL; orbit diameter 18–22%; upper jaw length 53–64%; filamentous rays of 1D, P, and V when intact slightly longer than head.* Head bones and integument notably thin and fragile. Color overall dark; fins, head, abdomen, mouth, and gill cavity usually black. (* indicates data from Gilbert and Hubbs, 1916).

DISTRIBUTION.— From n. part of Japan (Tohoku region of Honshu Is.) s. to Taiwan ( NET, SET, SCS) and on Emperor Seamounts Chain (at 40°05ʹN, 170°43ʹE), from about 800 to 1370 m.

REMARKS.— Chiou et al. (2004b:39, 42, fig. 5) recorded this species from Taiwan based on two specimens, but we re-identified one of them ( ASIZP 61226) as B. garretti . Bathygadus antrodes is closely similar to B. bowersi ( Gilbert, 1905) from Hawaii and to B. spongiceps Gilbert and Hubbs, 1920 from the Philippines and Indonesia. Characters used to distinguish the three are minimal and need to be further supported. A closer comparison with many more specimens from throughout the western and central Pacific should prove fruitful.