Coelorinchus productus Gilbert and Hubbs, 1916

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 : 66-67

Coelorinchus productus Gilbert and Hubbs, 1916

Coelorhynchus productus Gilbert and Hubbs, 1916:175–177 , pl. 9, fig. 1 (holotype, USNM 76865 ; Suruga Gulf , Japan, 197–297 fm [360–543 m]; paratypes, CAS-SU 22977 , USNM 76872 , 76873 ).

Coelorinchus productus : Yatou in Okamura and Kitajima, 1984:233, fig. 166 (p. 232), 369 (3 spec., 210–270 mm TL; Okinawa Trough, 410–600 m).— Iwamoto, 1990:179–180, fig. 406 (descr.).— Shao et al., 2008: table 2 (3 spec., NET, SWT, 100–650 m).

Caelorinchus productus : Chiou et al., 2004b:44, fig.11 (2 spec., NET).

MATERIAL EXAMINED (5 spec.).— NET: ASIZP 61326 (1, 296+ TL) , Da-xi; ASIZP 61327 (1, 221 TL) , Da-xi; ASZIP 65573 (1, 333 TL) , Da-xi; ASIZP 65644 (1, 239 TL) , Da-xi; ASZIP 65648 (1, 241+ TL) , Da-xi.

DISTINGUISHING FEATURES.— 1D II 8–10; P i16–i18; GR-I (inner) 6–8 total. Scales below midbase 1D 3.5–4.5, below 2D 4–6; pyl.caeca about 27. Snout sharply pointed, length 39–42% HL, 1.5–1.7 times orbit; anterolateral margin of snout completely supported by bone; orbit 26–29% HL, upper jaw 22–23% HL; nasal fossa scaled ventrally; underside of head naked except for occasional small patch below preopercle angle. Light organ group II of Iwamoto (1990), fossa narrow and short, not extending to pelvic-fin bases. Spinules on body scales daggerlike in 3–5 slightly divergent ridgelike rows, middle row strongest. Ground color grayish-brown, silvery ventrally, bluish over abdomen becoming blackish ventrally; mouth and gill cavity blackish; fins dusky to blackish. Attains about 310 mm TL.

DISTRIBUTION.— Pacific coast of s. Japan to ne. Taiwan in 271–651 m.

REMARKS.— Coelorinchus productus has been confused with the closely similar C. anatirostris , into which Okamura (1970:186) synonymized the species. However, Yatou (in Okamura and Kitajima, 1984:233) treated it as distinct, and Iwamoto (1990:130) and Nakabo (2002:434) provided characters by which the two species could be distinguished. Chiou et al. (2004b) used the specimens here listed to document the first record of the species in Taiwanese waters. In a recent paper, Fukui et al. (2010) re-synonymized C. productus with C. anatirostris based on examination of two specimens of the former and one of the latter, each collected in Suruga Bay. Their selected measurements and analysis of nucleotide sequences (16S rRNA) showed the two to be the same. However, their measurements do not wholly agree with those we took from our specimens of the two species. Aside from proportional measurements, which can sometimes be misleading because of individual variation, they mention no other character used to distinguish their specimens of each species. This raises the question of whether or not they actually had specimens of C. productus (or C. anatirostris ). Obviously, this problem needs further investigation; in the meantime, we will continue recognition of both species based on characters here given.