Desenvolvimento larval de quatro espécies de Symphurus Rafinesque, 1810 (Osteichthyes, Cynoglossidae) e sua distribuição na costa sudeste/sul do Brasil (23ºS-29ºS)

Abstract

Morphological and osteological development of four species of Symphurus larvae and juveniles are described, using the ichthyoplankton samples collected in the southeastern Brazilian Bight (from 23° S to 29° S). Larvae of four species are identified based on distribution pattern of pigments on the margin of dorsal and ventral sides of trunk and on the length of the first dorsal fin rays. All four species have a crest consisting of elongated dorsal rays. Symphurus ginsburgi Menezes & Benvegnú, 1976 larvae have one short first dorsal fin-ray followed by four long rays. A pair of melanophores are visible on posterior dorsal and ventral margins of trunk since preflexion stage. Only this species has a c onical structure attached to the gut coil. s. kyaropterygiurn Menezes & Benvegnú, 1976 larvae also have one short fin-ray f oll owed by four long rays, but can be distinguished frorn the f orrner species larvae by their pigrnent pattern, i.e., there are f our groups of rnelanophores on the dorsal rnargin of the trunk. s. plagusia {Bloch & Schneider, 1801) larvae have one short fin-ray f ollowed by two long rays and seven groups of rnelanophores on the dorsal rnargin of the trunk. s. trewavasae Chabanaud, 1948 larvae have four long dorsal fin rays (the osteological analysis showed that the first ray is elongated in this species) and six groups of rnelanophores on the dorsal rnargin of the trunk. There is a bathymetric segregation on the larval distribution patterns of the f our species, which c oincided with that of adults. s. plagusia larvae were collected at stations in shallow waters (20-30 m) and s. ginsburgi larvae were found in deeper waters (more than 120 m depth). The larvae of s. trewavasae and s. kyaropterygium were collected in intermediate waters over the c ontinental shelf.