Hymenocephalus longiceps Smith and Radcliffe, 1912

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 : 75-76

Hymenocephalus longiceps Smith and Radcliffe, 1912

Hymenocephalus longiceps Smith and Radcliffe in Radcliffe, 1912:111–112, pl. 23, fig. 3 (holotype, USNM 72928; off se. Luzon, Philippines, 201 fm [368 m]; paratypes, USNM 149297).— Yatou in Okamura et al., 1982:141, 346, fig. 85 (p. 140) (5 spec., 135–225.5 TL; Kyushu-Palau Ridge, 420–555 m).— Okamura in Masuda et al., 1984:93, pl. 80–D (compiled).— Okamura in Okamura and Kitajima, 1984:199, 357, fig. 140 (p. 198) (5 spec., 184–230 mm TL; East China Sea [Okinawa Trough], 353–490 m).— Shen et al., 1993:171 (descr.).— Chiou et al., 2004b:37, 47 (in key, list).— Shao et al., 2008: table 2 (41 spec., Taiwan [ NET, SWT, SCS], 227–1211 m).

Hymenocephalus (Hymenocephalus) longiceps : Gilbert and Hubbs, 1920:525–526 (63 spec., South China Sea off Hong Kong and Taiwan, Philippines, “ East Indies,” 107–298 fm [196–545 m]).— Okamura, 1970: 45–47, pl. XIV (9 spec., 156–240 m TL; Pacific coast s. Japan, 300–500 m).

MATERIAL EXAMINED (47 spec.).— NET: ASIZP 61235 (1, 195 TL), Da-xi ; ASIZP 61236 (6, 96–152 TL), Da-xi ; ASIZP 66373 (1, 160 TL), Nan-fang-ao . SCS: ASIZP 65546 (1, 160+ TL), CD 137, 316– 477 m ; ASIZP 65554 (1, 200 TL) and ASIZP 65563 (1, 160 TL), CD 142, 227– 335 m ; ASIZP 65589 (5, 125–155 TL) and ASIZP 65606 (4, 125+-170 TL), CD 136, 998– 1211 m . SWT: ASIZP 60321 (1, 128 TL), Dong-gang ; ASZIP 62270 (2, 100+-130+ TL), Dong-gang . SCS: ASIZP 66269 (1, 170+ TL) , ASIZP 66797 (13, 87+-118+ TL), and ASIZP 66879 (2, 63+-101+ TL), CD 311, 516 m ; ASIZP 66739 (1, 100+ TL), CP 315, 509 m ; ASIZP 66836 (1, 26.1 HL, 110+ TL) and ASIZP 66867 (1, 88 + TL), CP 314, 509 m ; ASIZP 66837 (1, 168+-177+TL), CD 311, 516 m. Other specimens: ASIZP 67841 (1, 200 TL), Aurora, 358– 342 m ; ASIZP 67949 (1, 90 TL), Aurora, 269–277 m ; ASIZP 68031 (1, 120 TL), Aurora, 500–524 m ; ASIZP 68192 (1, 166 TL), Auroa , 442–431 .

DISTINGUISHING FEATURES.— 1D II 9–10; P i13–i17; V 8; inner GR-I 18–23 total; pyl. caeca 18–22. Orbit 27–31% HL; upper jaw 53–59%. Head rather low, its length about 5–6. 5 in TL; body depth about 7–8 in TL. Snout low, broadly rounded, not projecting beyond mouth; barbel long, more than orbit, about 2 in HL. Attains about 240 mm TL. (Compiled from Okamura, 1970 and Gilbert and Hubbs, 1916).

DISTRIBUTION.— Known from s. Japan to South China Sea , Philippines, Sulu Sea , Bohol Sea, and Celebes Sea, in 196– 555 m. The species was taken in 227–1211 m depth off Taiwan.

REMARKS.— The long barbel and low, rounded snout distinguish this species from all others of the subgenus from Taiwan. It is closely similar to H. longibarbis Günther, 1887 and the two may be synonymous.