ABSTRACT The distributional patterns of 13 species of Diaptomus Westwood, 1836 were analyzed using the panbiogeographical method of track analysis. Locality records were compiled from the literature and mapped for the construction of individual tracks for each species. These tracks were superimposed to find the generalized tracks. Four generalized tracks were found: (1) Siberia, Central Europe, and Iceland; (2) Northern Italy, southern France, central Spain, northern Algeria, and northern Morocco; (3) Southern France, central Spain, and northern Morocco; (4) Southern Italy, Sicily, and Albania. Five biogeographic nodes were found: (A) Southwestern Iberia, (B) Southeastern Iberia, (C) Central Iberia, (D) Cantabria, at the intersections of generalized tracks 2 and 3; and (E) Italian Peninsula Islands, at the intersection of generalized tracks 2 and 4. The main massing of the species of Diaptomus studied is located in the Iberian peninsula, where six of the species do occur. A model based on the fragmentation and differentiation of already widespread ancestors during the late Mesozoic and early Cenozoic, related to the opening the North Atlantic Ocean and the formation of the Mediterranean Sea, is proposed as a most parsimonious explanation for the observed patterns of geographic vicariance.

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.