Coelorinchus cf. notatus, Smith and Radcliffe, 1913

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 : 64

Coelorinchus cf. notatus [sensu Smith and Radcliffe, 1912]

Figure 9.

MATERIAL EXAMINED.— NMMB-P11958 (90++ mm TL, large portion of tail missing, 35.5 mm HL); Taiwan; Nan-fang-ao; ca. 280 m.

DISTINGUISHING FEATURES.— 1D II, 9; P i16; GR-I (inner) 1+1+6, 8 total; scales below midbase 1D 3.5, below 2D 5.5; pyl.caeca 25. Snout sharply pointed in lateral view, sides gently convex in dorsal view, tipped with a short, broad scute, length 43% HL, anterolateral margin snout completely supported by bone; orbit 28% HL; upper jaw 23% HL. Nasal fossa and underside of head naked; spinules on body scales short, conical, in 5 or 6 almost parallel rows. Light organ short, extends forward slightly anterior to base of pelvic fins, Group II. Belly bluish, ventral aspects of body tail pale; a small (pupil width) ocellated black blotch above pectoral fin; underside of head almost entirely pale to whitish; mandibular rami and gill membranes pale; fins generally dusky, second 1D spine and tips of rays blackish; mouth and gill cavities blackish, but lips pale.

DISTRIBUTION.— Taiwan off Nan-fang-ao ( NET) in about 280 m.

REMARKS.— This single damaged specimen (tail mostly broken off, scales almost entirely missing on body and head) belongs amongst those Coelorinchus species that Gilbert and Hubbs (1920:446) included under the subgenus Paramacrurus Bleeker. Most of the species in this group have a dark blotch above the base of the pectoral fin, an acute snout slightly longer than diameter of orbit, lateral margins of snout fully supported by bone, snout with convex lateral profile (viewed dorsally), anus removed by a short distance from anal-fin origin, and light organ moderately developed with dermal window extending forward between pelvic-fin bases (and beyond in some species). The subgenus includes C. kishinouyei and C. jordani from Japan, and at least nine others from the Philippines-East Indies regions, including C. notatus , C. maculatus , C. velifer , C. sexradiatus , C. triocellatus , C. dorsalis , C. macrolepis , C. argus , and C. thurla . The Taiwan specimen follows very closely the original description and illustration of C. notatus Smith and Radcliffe, 1913 , as well as the more-extensive description provided by Gilbert and Hubbs (1920:462–465), who in a footnote (op. cit. p. 464) stated that none of Radcliffe’s “smaller specimens are true notatus .“ Thus, the species is known only from the holotype. NMMB-P 11958 differs from C. notatus in having a smaller pectoral blotch, which covers only four diagonal scale rows (cf. six in C. notatus ) and a snout with a straight dorsal profile (cf. slightly concave). Gilbert and Hubbs (1920:465) stated that “the belly is blackish only in advance of the ventrals,” but Radcliffe (1913:137) stated, “belly with blackish shades showing through scales.” In NMMB-P 11958, the entire underside of the trunk is dark bluish, from the gill membranes to beyond the anal-fin origin. The Taiwan specimen appears to have more saddle markings than does C. notatus . A broad dark saddle extends from before the mid-base of 1D to slightly beyond the origin of 2D. This saddle extends one or two scale rows below the lateral line, about to the mid-lateral line of the body; it is not as dark as the pectoral blotch or the short (5 or 6 rows wide) more-posteriorly situated saddle from which it is separated by a pale gap occupying three scale rows wide. A third, longer saddle that does not extend to the lateral line follows a pale gap of three scale rows; this shallow saddle is about 12 scales long and 2.5 to 3 scales deep. A fourth short saddle appears to be developed, although the specimen is so damaged that only parts of the integument remain and the precise limits of the marking could not be confidently acertained. The second and fourth saddles are about in the positions shown for the two saddle marks in the original illustration of the C. notatus (Radcliffe, 1913: pl. 30, fig. 3), which does now show the intervening saddles seen in NMMB-P 11958. The relatively poor condition of the Taiwan specimen does not allow us to confidently assign the specimen to a species. A judgement awaits the collection and study of additional, better-preserved specimens.

Figures

FIGURE 9. Coelorinchus cf. notatus [sensu Smith & Radcliffe, 1912], NMMB-P11958, 90+ mm TL.