Scientists have described a new species of striped Pimelodus catfish from the Rio Tapajos and Rio Tocatins in Brazil.
Frank Ribeiro and Carlos de Lucena named the new species Pimelodus tetramerus in a paper, written in Portuguese, in the current volume of the journal Iheringia Serie Zoologie.
Pimelodus tetramerus is similar in appearance to P. albofasciatus and P. blochii, and belongs to the P. maculatus group, which also includes P. clarias.
It can be distinguished from other Pimelodus by its colouration, with four dark horizontal stripes on the flanks. The uppermost stripe begins just posterior to the pre-dorsal plate and finishes at the end of the adipose fin, the second is wider than the first and runs above the lateral line to the caudal fin base.
"Both are fragmented on its anterior portion, forming dark points that may join to form a vermiculate pattern," wrote Ribeiro and de Lucena.
"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."
For more information see the paper: Ribeiro FRV and CAS de Lucena (2006) - Nova espcie de Pimelodus (Siluriformes, Pimelodidae) dos rios Tapajs e Tocantins, Brasil. Iheringia, Sr. Zool., Porto Alegre, 96(3):321-327, 30 de setembro de 2006.