Gnathophis asanoi

discussion

Remarks. This species originally described from the Philippines and newly recorded in Taiwan.

Annotated checklist of eels (orders Anguilliformes and Saccopharyngiformes) from Taiwan

discussion

Remarks. The vertebral formula and most proportions fit the original description. However, a number of differences are present in Taiwanese specimens. The 343 mm specimen has slightly larger values of preanal length (37.9 vs. 34.3 ‒ 35.7 % TL in type series) and trunk (22.6 vs. 19.7 ‒ 19.9 % TL), smaller eye (14.7 vs. 15.7 ‒ 17.8 % HL) and 137 total vertebrae (vs. 139 ‒ 140). The 291 mm specimen has a larger eye (20.6 vs. 15.7 ‒ 17.8 % HL). Both Taiwanese specimens have smaller gill openings (10.5 ‒ 11.8 vs. 14.3 ‒ 14.7 % HL) and shorter pectoral fin (23.9 ‒ 24.2 vs. 28.6 ‒ 29.4 % HL). There are only 9 POM pores in 291 mm specimen. We are not able to judge these differences, as not many specimens are available at present. More specimens are needed to address the variation of the present species. Four species of Gnathophis Kaup, 1859 are currently known from the northwestern Pacific: G. heterognathus (Bleeker, 1858), G. ginanago (Asano, 1958), G. xenica (Matsubara & Ochiai, 1951), and G. asanoi. Of these, G. heterognathus has the widest distribution, from Japan to the Philippines (Karmovskaya, 2004). Gnathophis ginanago and G. xenica have been recorded only from Japan, and G. asanoi

Notes on two rare conger eel species (Anguilliformes: Congridae) found in Taiwanese waters

materials_examined

Description of Taiwanese specimens. Head length 14.4 ‒ 15.3 % TL; preanal length 35.1 ‒ 37.9; predorsal length 16.8 ‒ 17.3; trunk length 20.2 ‒ 22.6; tail length 61.8 ‒ 64.9; depth at head ~ 4.2; depth at anus 3.4 ‒ 4.8; width at anus ~ 2.7. Snout length 31.3 ‒ 33.5 % HL; eye diameter 14.7 ‒ 20.6 % HL; interorbital width ~ 11.2; rictus 35.4 ‒ 41.1; gill opening width 10.5 ‒ 11.8; interbranchial width 19.6 ‒ 20.2; pectoral-fin length 23.9 ‒ 24.2. Body moderately elongate, cylindrical in cross section anteriorly, becoming more compressed posteriorly; tip of tail moderately attenuate; anus slightly behind anterior third of total length. Dorsal-fin origin slightly ahead tip of appressed pectoral fin, continuous around tip of tail with caudal and anal fins. Anal fin begins immediately behind anus. Pectoral-fin well developed, pointed distally with narrow base. Gill opening relatively small, smaller than eye diameter, its upper end nearly opposite middle of pectoral-fin base; interbranchial broader than gill opening and eye. Head moderately large reflected by the less slender body, deepest at about gill opening; snout long and pointed, its length 1.6 ‒ 2.1 times eye diameter, projecting

Notes on two rare conger eel species (Anguilliformes: Congridae) found in Taiwanese waters