Abundance and distribution of Bregmacerotidae (Pisces) larvae in Campeche Bay, Mexico

Abstract

The abundance and distribution of larvae and juveniles of the family Bregmacerotidae were studied at Campeche Bay (Mexico). The material was obtained from eight oceanographic cruises carried out between March 1981 and August 1988, covering the four seasons. Samples were taken with a bongo net in double-oblique tows. All larvae and juveniles were sorted from the samples and standard or notochordal length was obtained from each specimen, with a precision of 0.1 mm. A total of 6,122 larvae and juveniles were obtained of four species, which were, in order of abundance: Bregmaceros cantori (95.5%) B. atlanticus (4.2%), B. macclellandi (0.4%) and B. houdei (0.02%). The distribution and abundance of larvae in general and the size distribution in particular, let us characterize B. cantori as a neritic species, with its main spawning zone in areas between 20 and 100 m depth. Bregmaceros macclellandi, on the other hand, was characterized as oceanic, province in which it lives and spawns; the presence of some of its larvae over the continental shelf must be a consequence of local currents. Bregmaceros atlanticus had an intermediate situation between the two previous species, because the highest larval densities, particularly of those of smaller size, occurred in the outer shelf (areas ~100 m depth) and in the oceanic area adjacent to the continental slope.