Pimelodidae

The family Pimelodidae has undergone much revision. Currently, it contains about 30 genera and about 90 recognized and known but unnamed species. Wikipedia lists 109 species in this family. The low-eye catfish (previously family Hypophthalmidae), and thus the genus Hypophthalmus, which contains four species, was reclassified with the pimelodids.

This family previously included fish that are now classified under Pseudopimelodidae (previously subfamily Pseudopimelodinae) and Heptapteridae (previously subfamily Rhamdiinae). This family also previously included Conorhynchos conirostris, currently incertae sedis. However, a molecular analysis has shown unequivocal support for monophyly of the individual families and the genus Conorhynchos into a clade called Pimelodoidea, including Pimelodidae + Pseudopimelodidae and Heptapteridae + Conorhynchos.

Some genera have relatively recently been synonymized. Merodontotus and Goslinia are now both included under Brachyplatystoma. Also, Paulicea is now a synonym of Zungaro.

The six main groups within Pimelodidae are Steindachneridion, the Phractocephalus-Leiarius group, the Pimelodus group, the Calophysus group, Zungaro, and the Sorubim group. The Pimelodus group includes Pimelodus, Exallodontus, Duopalatinus, Cheirocerus, Iheringichthys, Bergiaria, Bagropsis, Parapimelodus, Platysilurus, Platystomatichthys, and Propimelodus. The Calophysus group includes the five genera Aguarunichthys, Pimelodina, Calophysus, Luciopimelodus, and Pinirampus.

The relationships within each genus are still being studied. Most genera lack a hypothesis for monophyly.