Description of the Larvae of Paracallionymus costatus and the Distribution of Its Eggs and Larvae in the Southeast Atlantic

Abstract

The distributional range of Paracallionymus costatus (Boulenger, 1898) spans the southeast Atlantic and southwest Indian oceans. A first description of its larval development is presented; until now only its eggs and yolk-sac larvae had been described. The specimens used in this study were collected in plankton samples taken off the west coast of South Africa on two surveys, one in winter and one in summer. Identification of the larger specimens was based on meristic characters, the presence of a single undivided spine in the preoperculum, and the existence of numerous ladder-like transverse branches along the lateral line, across the occipital region and on the dorsal part of the caudal peduncle. The description of the larval series includes morphological and morphometric characters and pigmentation. Relationships between the various body parts and standard length during development have also been considered. The most prominent features of these larvae are the large number of melanophores over the entire body and the increasing depression of the forebody as development proceeds. Information on the spawning area and season of this species, which is observed to spawn all along the west coast of South Africa over most of the year, is also presented.