A reassessment of the eels of the genus Bathycongrus in the Indo‐west Pacific

Abstract

Difficulties in identifying the species of the congrid eel genus Bathycongrus Ogilby, 1898 that frequent the upper slope in the Indo‐west Pacific arise principally because these eels possess very few distinctive external characters. The differences in body proportions between the seven species that are recognized here are not easy to evaluate because of the frequent loss and subsequent regrowth of the tail tip. There are differences in the size and number of vomerine teeth, though these are not readily quantifiable, and in the number of vertebrae. However, the combination of these two characters allows the recognition of large/small‐toothed forms and those with low‐count, mid‐count, and high‐count vertebral numbers. The solution here has been to lump together some of the 16 nominal species.Accordingly, seven Indo‐west Pacific species are recognized in this account. Uranoconger Fowler, 1934 is synonymized with Bathycongrus. Larval characters, especially the number of myomeres, may be of some assistance in resolving the problems of species identification. A key to the species is given.