Coelorinchus parallelus ( Günther, 1877 )

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 : 65-66

Coelorinchus parallelus ( Günther, 1877)

Macrurus parallelus Günther, 1877:439 (syntypes, BMNH 1887.12.7.65–68[4], 1887.12.7.69 [1]; MNHN 1890–0125 [ex BMNH] [1]; NMI block reg. no. 114.1899 [1]; off Inoshima , Japan, Challenger sta. 232, 345 fm [631 m]. Specimens [4] from New Zealand and Kermadec Islands subsequently renamed C. kermadecus Jordan and Gilbert, 1904).

Coelorhynchus parallelus : Okamura, 1970:198–200, pl. XLIII, text-fig. 86 (2 spec., 400–450 mm TL; Japan).

Coelorinchus parallelus : Kyushin et al., 1977:42 Okamura in Masuda et al., 1984:98–99, pl. 83–3 (compiled).— Yatou in Okamura and Kitajima, 1984:245, fig. 171 (p. 244), 370 (9 spec., 275–480 mm TL; Okinawa Trough, in 650–990 m).— Iwamoto, 1990:178–179, fig. 404 (compiled).— Iwamoto and Merrett, 1997:500–502, fig.12 (3 spec., New Caledonia region, 412–970 m).— Iwamoto et al., 1999:52.— Merrett and Iwamoto, 2000:746–747, fig. 12 (5 spec., Vanuatu, Norfolk Ridge, Lord Howe Rise, in 764–1124 m). — Shen et al., 1993:170 (descr.).— Shao et al., 2008: table 2 (3 spec., SWT, 100–650 m).

Caelorinchus parallelus : Chiou et al., 2004b:36, 47 (in key, list).

Coelorinchus commutabilis : Shao et al., 2008: table 2 (1 spec., SCS, 731 m; first record from Taiwan).

MATERIAL EXAMINED (6 spec.).— NET: ASIZP 65570 (1, 635+ TL) , KSD sta.3; ASIZP 70690 (1, 380 TL) , Da-xi. SWT: ASIZP 65542 (1, 405 TL) , CD 138, 441 m; ASIZP 65630 (1, 146 HL, 404 TL) and ASIZP 70271 (1, 430 TL) , CD 230, 810– 850 m; ASIZP 66108 (1, 350+ TL) , OCP 301, 687 m. SCS: ASIZP 66785 (1, 62 HL, 210 TL) and CAS 224496 (ex ASIZP 66785 ) (1, 61 HL, 220 TL), CD 320, 731 m.

DISTINGUISHING FEATURES.— 1D II, 8–9; P i17–i18; GR-I (inner) 7–8 total; scales below midbase 1D 3.5–4.0, below 2D 4.5–5.5; pyl. caeca about 9. Snout long, sides converge in gentle curve towards sharp spinous scute at tip, length 42–48% HL, anterolateral margin snout incompletely supported by bone; orbit 23–27% HL; upper jaw 22–26% HL. Nasal fossa and underside of snout scaly; body scales large, spinules stout, broad-based, in 1–6 parallel rows; scales of head mostly with spinules arranged in single parallel ridge-row. Light organ short, scarcely visible before vent; Group I of Iwamoto (1990). Color brown, to grayish; mouth and gill cavities dark; fins dusky to blackish. Attains about 450 mm TL.

DISTRIBUTION.— Pacific coast of s. Japan to Taiwan, East China Sea , South China Sea, and sw. Pacific. In Taiwan, specimens were collected from NET and SWT in depths of 441–850 m.

REMARKS.— Coelorinchus parallelus has a reportedly disjunct distribution in the western Pacific. Its apparent absence from the Philippines and Indo-Australian Archipelago and its reported presence on oceanic elevations in the sw. Pacific is suspicious. Specimens from the latter area should be examined in greater detail to confirm their conspecificity with the type specimens. Among the Taiwan Coelorinchus species with a simple (Group I) light organ, C. parallelus can be distinguished by the combination of broad spinules on body scales arranged in 4–6 parallel rows and its incompletely supported anterolateral snout margin. The two Taiwan specimens previously reported as C. commutabilis by Shao et al. (2009) from the SCS are questionably recorded here as this species. In almost all features, they fall in well with C. parallelus , but the spinules on their body and head scales are more slender and lack the broadly transverse buttresses characteristic of C. parallelus . Also, the nasal fossa is sparsely scaled anteriorly and the snout viewed dorsally is somewhat broader and more convexly curved. That these SCS specimens are relatively small (210+- 220+ mm TL) may account for the differences. A good size series is necessary to confirm these differences.