Gadomus cf. multifilis (Gunther, 1887)

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 : 43

Gadomus cf. multifilis [sensu ( Günther, 1887)]

Figures 3A–B .

Gadomus multifilis ( Günther, 1887) : Shao et al., 2008: table 2 (4 spec., SWT, first record for Taiwan).

MATERIAL EXAMINED (9 spec.).— SWT: ASIZP 64092 (4, 30–50.6 HL, 130+-260+ TL) ; CD 193, 821 m. SCS: ASIZP 66334 (1, 38 HL, 240 TL) and ASIZP 66240 (1, 37.1 HL, 223+ TL) , CD 307, 1591 m; ASIZP 66189 (1, 35.1 HL, 170+ TL) and ASIZP 66810 (1, 35.5 HL, 185+ TL) ; CD 322, 1098 m. Other specimens: ASIZP 68056 (1, 34.7 HL, 223 TL) ; CC2702 Aurora, 944–1004 m, 27 May 2007 .

DISTINGUISHING FEATURES.— A species of Gadomus with chin barbel about 50–75% of HL; length elongated P ray 2–3 times HL, prolonged ray in 1D and V much greater than HL; 1D II,8–9, P i16–i19; V 8; outer gill rakers sharply tipped, lathlike (6–7) + (23–26); pyl. caeca 24–29. Interorbital width 16–17% HL, orbit diameter 21–24%; suborbital depth 10–15%; upper jaw length 55–60%; chin barbel 29–72% (compiled from Gilbert and Hubbs, 1920).

DISTRIBUTION.— Taiwan ( SWT, SCS) and broadly across Indo-West Pacific, if these specimens are the same as G. multifilis .

REMARKS.— Our identification of nine Taiwan specimens has been problematical, although they for the most part fit the original description and subsequent descriptions of G. multifilis by Gilbert and Hubbs (1920) and Howes and Crimmen (1990). However, four of the ASIZ specimens ( ASIZP 64092) have a slightly lower count of GR-I (6 + 23) and more pyloric caeca (30–47 in 4 spec.); ASIZP 66334 had more rakers, 7 + 26 rakers. Gilbert and Hubbs (1920:406–408) gave the gill-raker count as 6 + (26–27) and pyloric caeca as 12 and 16. Howes and Crimmen (1990:195–197) counted 6 + 25 gill-rakers for the holotype and eight other specimens, and counts of 25 and 15 pyloric caeca in two of those specimens. The low gill-raker counts and high pyloric caeca counts of ASIZP 64092 agree rather well with those Gilbert and Hubbs (1920:403) gave for G. introniger (gill-rakers (5–6) + (20–24) and “pyloric caeca [in several specimens, 35 to 52”]). However, the orbit diameter and interorbital width are less in our specimens and the gill-rakers are pointed, not bluntly tipped, as in G. introniger . Similarly, the counts of gill-rakers and pyloric caeca, plus the interorbital and orbit dimensions, agree closely with G. magnifilis , but the gill-rakers are also bluntly tipped in that species. We see no resolution to our dilemma without a thorough revision of the genus using extensive material from throughout the Indo-West Pacific, and especially from that critical region around the Philippine Islands and the Malay Archipelago.

Figures

FIGURE 3. Gadomus cf. multifilis [sensu (Ganther, 1887)] A. ASIZP 64092, 260+ mm TL, fresh. B. ASIZP 66334, 240 mm TL, preserved.