New species of the genus Bathycongrus—B. parviporus (Congridae, Anguilliformes)—from waters of Central Vietnam (Nha Trang and Van Phong Bays)

Abstract

Bathycongrus parviporus sp. nova is described from specimens collected in the South China Sea, in the coastal waters of central Vietnam. By its characters (short snout, elongate-oval vomerine tooth patch with numerous small teeth of approximately the same size, slender relatively short tail, and residual leptocephalic pigmentation as a series of small melanophores just below lateral line in adults), the species belongs to the group of species of this genus represented by B. bleekeri, B. trimaculatus, and B. unimaculatus in the western part of the Pacific Ocean and B. dubius in the western Atlantic Ocean but differs in small infraorbital pores which are enlarged in all known species of the genus Bathycongrus. By the number of preanal pores, the new species is similar to B. bleekeri from Philippine waters but differs from it in a higher number of vertebrae (120–122), in more numerous rows of teeth on the premaxilloethmoid, in more number of branchiostegal rays (9–10), a shorter head, and in some other proportions of head and body. Topography of canals and pores of the cephalic seismosensory system of B. parviporus sp. nova is described. Morphometric and osteological characters for placing this species in the genus Bathycongrus are noted.