ABSTRACT
The Siluriformes, or catfishes, with more than 430 genera and 2750 species, represent about one third of all freshwater fishes. The relationships between the various siluriform families have long been studied. However, the number of works focused on this subject increased considerably in the past few decades because of the renewed impetus provided by the advent of cladistics in the second half of the 20th century. In this chapter, we provide an overview of those cladistic studies on the higher-level phylogeny of the Siluriformes, as a foundation for an overall discussion on the state of the art of catfish phylogeny. As will be shown, considerable progress has recently been achieved in this field, and we are arriving at some consensus concerning certain aspects of catfish higher-level phylogeny: e.g., the close relationship between ictalurids and cranoglanidids, between anchariids and ariids, and between the pimelodids, pseudopimelodids and heptapterids; the basal position within the order of the Diplomystidae, the Loricarioidei, the Cetopsidae and the Hypsidoridae; the monophyly of a clade including Heteropneustes and clariids, of a clade including auchenipterids and doradids, of a clade 466including erethistids, sisorids, akysids, amblycipitids and perhaps aspredinids; and the sister-group relationship between the clade Nematogenyidae + Trichomycteridae and the clade Callichthyidae + (Scoloplacidae + (Astroblepidae + Loricariidae)). However, despite the recent progress in catfish phylogeny, much remains to be done. For example, we are far from reaching a consensus about the relationships, and in some cases even the monophyly (e.g., Claroteidae, Bagridae, Schilbidae), of families such as the Siluridae, Austroglanididae, Schilbidae, Claroteidae, Malapteruridae, Bagridae, Mochokidae, Lacantuniidae, Chacidae, Plotosidae, and Amphiliidae.
