Descrição de duas novas espécies de Sciaenidae (Perciformes) de água doce da Bacia Amazônica

Abstract

RESUMO -São descritas duas novas espécies de Sciaenidae da região Amazônica, pertencentes aos gêneros Pachyurus e Plagioscion. Pachyurus junki sp. n. difere das demais espécies congenéricas descritas por apresentar a seguinte combinação de caracteres: extremidade no comprimento da cabeça; segundo espinho da nadadeira anal contido mais do que 2,1 vezes no comprimento da cabeça; 29 a 33 raios na nadadeira dorsal; 11 a 16 séries de escamas acima da linha lateral; 11 a 16 séries de escamas abaixo da linha lateral e 58 a 68 escamas perfuradas na linha lateral. Plagioscion montei sp. n. difere das demais espécies do gênero por apresentar: ânus distante da nadadeira anal, estando a distância ânus-anal contida de 2,4 a 3,5 vezes no comprimento da cabeça; nadadeira peitoral relativamente longa, quando adpressa sua extremidade posterior chega próximo ou ultrapassa a linha vertical que passa pela origem do ânus; largura interorbital relativamente ampla, contida entre 3,5 e 5,0 vezes no comprimento da cabeça e segundo espinho da nadadeira anal forte e curto, contido de 2,5 a 4,4 vezes no comprimento da cabeça. Palavras-chave:Pachyurus, Plagioscion, Sciaenidae, nova espécie, bacia Amazônica. Description of Two New Species of Freshwater Sciaenidae (Perciformes) from Amazon River Basin.ABSTRACT -Two new species of freshwater Sciaenidae genera Pachyurus and Plagioscion are described from Amazon River basin. Pachyurus junki sp. n. differs from its congeners by the following characters combination: posterior tip of pelvic fin distant from the anus, interorbital width less than 6.0 times in the head length, second anal fin spine more than 2.1 times in the head length, 29 to 33 soft rays in the dorsal fin, 11 to 16 rows of scales above to lateral line, 11 to 16 rows of scales below, and 58 to 68 perfored scales in the lateral line. Plagioscion montei sp. n. differs from its congeners by having: anus distant from the anal fin, the distance anus-anal fin from 2.4 to 5.0 times in the head length; pectoral fin relatively long, when adpressed its large, from 3.5 to 4.9 times in the head length, and second anal fin spine strong and short, from 2.5 to 4.4 times in the head length.

Molecular taxonomy of Plagioscion Heckel (Perciformes, Sciaenidae) and evidence from mtDNA RFLP markers for an invasive species in the Paraná river, Southern Brazil

“…Therefore, in comparing the geographical distributions among all Plagioscion species with that of Plagioscion et al (2004) sp. (SLOSS et al 2004) we suggest that the present molecular characterization could be attributed to Plagioscion montei (SOARES & CASATTI 2000) since P. montei is the single species sampled for some river in Peru (also see SLOSS et al 2004). Finally, the present approach suggests that molecular techniques may offer a very precise method of identifying biodiversity as well as recognizing invasive species.…”

Two New Otolith-Based Sciaenid Species of the Genus Plagioscion From South American Neogene Marine Sediments

“…The total length records of the living freshwater species of Pla gioscion [P. auratus; P. casattii; P. montei Soares and Casatti, 2000;P. squamosissimus;P.…”

“…squamosissimus;P. surinamensis (Steindachner, 1879), and P. ternetzi Boulenger, 1895] from the South America basin range from 11.3 cm to 67.5 cm (Aguilera and Rodrigues de Aguil era, 2000;Annibal, 1983;Casatti, 2000;Oliveira, 1972;Oliveira E Silva and Simoes de Menezes, 1950;Soares, 1978;Soares and Casatti, 2000;herein). From this information it can be assumed that the length distribution of the fossil Neogene species over lapped the length distribution of the living freshwater species (Fig.…”

“…Among the freshwater fishes, the worldwide Sciaenidae (croak ers or drums) are represented by three genera and 20 living spe cies in the river systems of South America. Of the three genera, Plagioscion is represented by six previously described species (Aguilera and Rodrigues de Aguilera, 2000;Casatti, 2000;Soares and Casatti, 2000).…”