Atherinella blackburni (Schultz, 1949) (Atherinopsidae), is known in the Atlantic Ocean in Costa Rica, south of Caribe and from Venezuela to central Brazil. The distribution and the intraespecific variation of characters of A. blackburni are poorly known. This study records A. blackburni in Bahia littoral and presents more informations about its intraespecific variation.

A check-list of fishes collected in a mangrove in Cacha Pregos, south of ltaparic Island, State of Bahia, Brazil (about 13o07'S,38o48'W) from 1988-1989 and 1991-1992 is presented. Fifteen orders, 46 families and 85 species (Teleostei except one Chondrichthyes) were identified, represented specimens whose adults live in different marine ecossystems.

Patterns of geographic variation in 10 morphometric characters were analyzed in a sample of 91 specimens of the batfish, Ogcocephalus vespertilio (L.), from the NE and SE Brazilian coast, using multivariate statistics and randomization tests. The specimens were ordinated by principal components analysis in two groups corresponding to the regions north and south of the 23ºC isotherm, and size variation was found to account for 70.3%, whereas shape differences accounted for 23.6% of the total variation in morphometric characters. The two groups were different at the 1% significance level by multivariate analysis of variance based on the Wilk's criterion, tested by a randomization procedure. Width of illicial cavity and distance from anus to anal fin were the characters most contributing to the differentiation of the population samples.

Comparative morphometrics of Ctenosciaena gracilicirrhus, Paralonchurus brasiliensis and Micropogonias furnieri (Teleostei: Sciaenidae) by multivariate analysis of truss networks. Morphological differentiation among three species of sciaenid fishes, Ctenosciaena gracilicirrhus, Paralonchurus brasilliensis and Micropogonias furnieri, was analyzed by multivariate statistical techniques, using measuraments obtained from truss networks based on anatomical landmarks. Principal components analysis of interlandmark distances defined by the truss system showed that the individuais of Ctenosciaena gracilicirrhus are different from those of the other two species in relation to shape, being more similar to the individuals of Micropogonias furnieri in relation to size.

The present paper is the first part of the catalogue of marine fishes belonging to the collection of the Laboratory of Ichthyology (Universidade Federal do Rio de Janeiro-RJ) to be published. Here are included Chondrichthyes (Rajiformes) and part of Osteichthyes, Teleostei (Elopiformes to Dactylopteriformes) in a total amount of 30 families, 52 genera and 62 species. The most part of the material have been collected at the littoral of the State of Rio de Janeiro. For each species considered is given the vulgar name (when known in Southeastern Brazil), the known distribution (in Western Atlantic Ocean) and some data as collecting locality, total number of collected specimens and the register number in the collection. Scorpaena isthmensis Meek & Hildebrand, 1928 (Scorpaenidae) is for the first time mentioned for the Southern littoral of Brazil.