Nova espécie de Pimelodus (Siluriformes, Pimelodidae) dos rios Tapajós e Tocantins, Brasil

Abstract

ABSTRACT. A new species of Pimelodus (Siluriformes, Pimelodidae) from Tapajós and Tocantins rivers, Brazil. Pimelodus tetramerus sp. nov. differs from the other species of Pimelodus Lacepède by its typical coloration, with four dark stripes on the sides of the body, the most dorsal beginning just behind the pre-dorsal plate and finishing at the end of the adipose-fin base; the second, wider than the first one, running just above the lateral line and extending from the lateral border of the supra-occipital process to the caudalfin base. Both are fragmented on its anterior portion, forming dark points that may join to form a vermiculate pattern. The dark dots and the vermiculate pattern extend over the dorsum, anterior to the dorsal-fin and head. The third stripe, also wide, runs just below the lateral line and begin near the upper region of the postcleithral process and extends until the caudal fin base. The fourth stripe, shorter than the three others, and absent in a few cases, begins above of the postcleithral process and ends nearly the pelvic fin. Moreover, the following are also diagnostic of the new species: presence a narrow light stripe on the lateral line, with about 1/3 of the width of the third dark stripe, and a dark longitudinal bar on the ventral lobe of caudal fin. The new species shares the three separate trigeminofacial nerve foramina with others species of pimelodids. KEYWORDS. New species, "mandi", taxonomy, lower Amazonas river. RESUMO. Pimelodus tetramerus sp. nov. difere das outras espécies de PimelodusLacepède por sua coloração típica, que consiste de quatro faixas escuras sobre os lados do corpo, a primeira, mais dorsal, iniciando logo após o final da placa pré-dorsal e terminando no final da base da nadadeira adiposa; a segunda, mais larga que a primeira, logo acima da linha lateral, percorre desde a borda lateral do processo supra-occipital até a base da nadadeira caudal. Ambas faixas estão fragmentadas em sua porção anterior, formando pontos escuros que, ocasionalmente, podem estar unidos, compondo um padrão vermiculado. Tais pontos escuros e/ou padrão vermiculado se distribui sobre a região pré-dorsal e cabeça. A terceira faixa, tão larga quanto a segunda, logo abaixo da linha lateral, inicia junto à região superior do processo pós-cleitral e estende-se até a base da nadadeira caudal e a quarta, de menor comprimento, podendo estar fraca ou ausente, iniciase logo abaixo do processo pós-cleitral e finaliza até próximo à nadadeira pélvica. Além disso, constituem caracteres diagnósticos da nova espécie a presença de uma estreita faixa clara sobre a linha lateral, com aproximadamente 1/3 da largura da terceira faixa escura, e a presença de uma barra escura percorrendo longitudinalmente o lobo ventral da nadadeira caudal. A nova espécie compartilha o forâmen trigeminal tripartido com outras espécies de pimelodídeos. PALAVRAS-CHAVE.Nova espécie, mandi, taxonomia, baixo rio Amazonas.

Karyotype variability in neotropical catfishes of the family Pimelodidae (Teleostei: Siluriformes)

“…Among the great catfishes, the Steindachneridion and Pseudoplatystoma genera occupy the top of the alimentary chain; present great load and migrate in at least a phase of the life (Miranda, 1997;Revaldaves et al, 2005). The genus Pimelodus has the greatest diversity in the Pimelodidae family, with 26 species distributed from Panama to Argentina, ranging from small to medium-size (Lundberg & Littmann, 2003;Ribeiro & Lucena, 2006a, 2006b. The genus Sorubim is distributed in hydrographic basins of the Amazon, Orinoco, Paraná and Paraíba Rivers (Froese & Pauly, 2002).…”

Three new Pimelodus species (Siluriformes: Pimelodidae) from the rio Tocantins drainage, Brazil

“…Instead, each has centrum 7 exposed ventrally and the superficial ossification is restricted to more anterior vertebrae . It is important to emphasize that this character exhibits different ontogenetic states, including an exposed seventh vertebral centrum (Azpelicueta, 2001;Ribeiro & Lucena, 2006b). Lundberg et al (1991b), and Lundberg & Parisi (2002) also identified one derived state of the trigeminofacial nervecomplex (and respective foramina), which diagnoses a group of Pimelodus species, including P. maculatus (type-species).…”

“…Osteological terminology follows Lundberg & Luckenbill (2007). Comparative material is that listed by Ribeiro & Lucena (2006a, 2006b and additional specimens listed below under "Additional Examined Specimens". Fig.…”

The philometrid nematodePhilometroides acreanensis n. sp. from the stomach wall of the catfishPimelodus blochiiin north-western Brazil

“…Bloch's catfish is one of eight species of Pimelodus Lacépède occurring in the Amazon River drainage system. This is a highly appreciated and the most consumed species in the region, considered by locals to be a tasty and cheap fish (Padovani et al , 1996; Boujard et al , 1997; Ribeiro & Lucena, 2006).…”