A tentative Tholichthys stage in development of Ostracoberyx and its bearing on systematics of Ostracoberycidae

Abstract

The unusual larval stage of Ostracoberyx dorygens is described for the first time. A late larva is characterized by a deep body, a very large head with strong spines on preopercular, supraoccipital, and lacrimal bones and a head completely encased with hypertrophied surface bones. Based on a number of morphological characters, this larva is very similar to the pelagic “tholichthys” stage of chaetodontids. A possible relationship between these two families is hypothesized based on similarity of their early stages.