A new species of Astronesthes (Actinopterygii, Stomiidae, Astronesthinae) snaggletooth from the tropical western Pacific, with comments on the occurrence of Astronesthes luetkeni Regan and Trewavas in Japanese waters

Abstract

A new species of snaggletooth, Astronesthes kiyofujii, is described from a single specimen (98.5\xa0mm in standard length, SL) collected from the tropical western Pacific off the Republic of Palau. It belongs to the Astronesthes luetkeni group and differs from other congeners in having the following combination of features: chin barbel very long (64.9% SL), distinctly longer than head length; barbel bulb slightly swollen, without any filaments; luminous tissue on gill cover forming slender vertical line along hind margin of preopercle, partly discontinuous ventrally; longitudinal stripe of subcutaneous luminous tissue extending midventrally from chest to belly; serial photophores numerous and closely spaced; photophores from isthmus to pectoral-fin base (IP) arranged in almost straight line, only slightly arched in front of pectoral-fin base; photophores from above anal-fin base to caudal-fin base (AC) forming continuous line, not broken into sections; anal-fin origin distinctly behind vertical through dorsal-fin insertion; dorsal-fin base slightly longer than (1.4 times) anal-fin base; dorsal-fin rays 16; anal-fin rays 16; pectoral-fin rays 8; vertebrae 34\u2009+\u200915\u2009=\u200949; body uniformly black except for luminous tissue patches; barbel stem pale, except proximal end with scattering of external melanophores; barbel bulb with diffuse patch of external melanophores on one side, paler on the other side. In addition, we report the first voucher-based records of the Indo-Pacific Astronesthes luetkeni Regan and Trewavas 1929 from the Japan’s Exclusive Economic Zone, proposing a new standard Japanese name for the species.