A Larva of the Atlantic Flashlight Fish, Kryptophanaron Alfredi (Beryciformes, Anomalopidae), with a Comparison of Beryciform and Stephanoberyciform Larvae

Abstract

The first wildcaught larva of a flashlight fish is described from a single specimen of Krypfophanaron alfredi, 6.2 mm NL, collected with a midwater trawl in the Tongue of the Ocean, Bahamas. The larva lacks light organs, but an antrorse projection on each side of the snout represents at least the stalk of an incipient light organ. Other distinguishing features of larval Kryprophanaron include an elongate, heavily pigmented pelvic fin; a patch of pigment on and between the anteriormost dorsal-fin spines; numerous melanophores covering the head and trunk (but conspicuously absent on the caudal peduncle); prominent head spines and spiny scales. The distribution of head spines among larvae of major acanthomorph lineages is confusing phylogenetically, and larval specializations do not help resolve current controversy about ''beryciform'' monophyly. Larval morphology provides some support for a close relationship between the Berycidae and other berycoid families and corroborates hypotheses based on adult characters that: Anoplogastridae, Diretmidae, Anomalopidae, Trachichthyidae, and Monocentridae form a natural assemblage; anoplogastrids and diretmids are sister taxa; and trachichthyoids (anomalopids, trachichthyids, and monocentrids) are monophyletic. Larval features highlight a need to reassess relationships among trachichthyoids.