[3] This fish was described by Achille Valenciennes in 1840, originally under the genus Bagrus.

[1] It inhabits marine, brackish and freshwaters ranging from Brazil to Colombia.

[3] The crucifix sea catfish has an extensive diet, consisting largely of crustaceans such as crabs in the genera Callinectes (C. bocourti, C. danae, and C. ornatus), Petrolisthes, and Porcellana (P. sayana); shrimp and prawns in the genera Alpheus, Exhippolysmata (E. oplophoroides), Nematopalaemon (N. schmitti), Penaeus (P. schmitti), and Xiphopenaeus (X. kroyeri); and isopods.

It also feeds largely on eels in the families Muraenesocidae and Ophichthidae, and other bony fish in the genera Anchoa, Aspistor (A. quadriscutis), Cathorops ( C. arenatus, C. phrygiatus and C. rugispinis), Evermannichthys, Gobioides, Plagioscion, Pseudauchenipterus (P. nodosus), Stellifer (S. microps and S. rastrifer), Synbranchus (S. marmoratus), and Trichiurus.

It also feeds on annelid, polychaete and roundworms, as well as ariid larvae, insects, gastropods, and leaves and twigs from terrestrial plants.