Bathycongrus albimarginatus

discussion

Remarks. Newly described in this volume by Huang et al. (2018). The species is only found in eastern Taiwan off Taitung; collected by hook and line.

Checklist of eels of Taiwan (orders Anguilliformes and Saccopharyngiformes): An update

description

Description. The following values are given for the holotype, followed by the range of all types in parentheses. Body rather stout, rounded in cross section anteriorly, becoming more compressed behind anus and in posterior portion; head strong and stout, its depth and width slightly smaller than those of trunk; trunk moderately long, its length 2.3 (2.0 – 2.5) times head length; tip of tail tapering and filiform; anus near anterior two-fifths of total length (when tail complete). Dorsal fin begins over posterior half of pectoral fin, continuous around tip of tail with caudal and anal fins. Anal fin begins immediately behind anus. Pectoral fin well developed, roundly pointed distally with a narrow base. Gill opening large, about same as eye diameter or slightly smaller, its upper end nearly opposite middle of pectoralfin base. Interbranchial width much greater than twice width of gill opening. Head relatively small, its length 12.1 % (10.9 – 13.1 %) TL, 30.4 % (27.9 – 33.5 %) PAL, deepest at about occiput, slightly tapering anteriorly from this point; dorsal profile nearly flat from occiput to internasal space; snout stout and broadly rounded, its length greater than eye diameter, p

Two new species of the conger eel genus Bathycongrus (Anguilliformes: Congridae) from Taiwan

diagnosis

Diagnosis. A moderately large, robust species of Bathycongrus with 2 enlarged teeth surrounded by small teeth on the vomer; body dark grayish with broad bright white margins on dorsal and anal fins; 5 pores on supratemporal canal; preanal vertebrae 50 – 52, precaudal vertebrae 68 – 70, total vertebrae 196 – 201; and preanal lateral-line pores 47 – 53.

Two new species of the conger eel genus Bathycongrus (Anguilliformes: Congridae) from Taiwan

discussion

Remarks. Bathycongrus albimarginatus sp. nov. belongs with the congeners with 2 enlarged teeth surrounded by small teeth on the vomer, which comprise 8 species previously, and can be distinguished by having more total vertebrae (196 – 201). Table 2 shows 6 meristic characters to differentiate these species (Castle & Smith, 1999; Karmovskaya, 2009; Smith & Ho, 2018). Of them, B. albimarginatus is most similar to Bathycongrus parapolyporus Karmovskaya, 2009 in having 11 preopercular-mandibular pores and 8 infraorbital pores. It can be further distinguished from B. parapolyporus in having the rictus extend to nearly below posterior margin of eye (vs. to mid-eye level); 196 – 201 total vertebrae (vs. 158 – 160); 11 – 13 pores before dorsal-fin origin (vs. 9 – 10); 5 supratemporal pores (vs. 1); additional small pores on head (vs. none); and clear white margin on vertical fins (vs. no clear white margin). The character of vertical fins with distinct white margin in B. albimarginatus rarely appears on the other Bathycongrus species. The outermost supratemporal pore is located at the junction of the temporal, preopercular, and lateral-line canals. We assign it to the supratemporal canal b

Two new species of the conger eel genus Bathycongrus (Anguilliformes: Congridae) from Taiwan