Cetopsinae, Bleeker, 1858

Vari, Richard P., Ferraris Jr, Carl J. & de Pinna, Mário C. C., 2005, The Neotropical whale catfishes (Siluriformes: Cetopsidae: Cetopsinae), a revisionary study, Neotropical Ichthyology 3 (2), pp. 127-238 : 130-131

Subfamily Cetopsinae

Systematic Overview. In the following sections we treat the recognized genera and species of the Cetopsinae . According to the results of this study, the Cetopsinae includes 37 species in four genera. Each of these genera, Cetopsidium , Cetopsis , Denticetopsis , and Paracetopsis , is hypothesized to form a monophyletic lineage (unpublished results) and is externally diagnosable by a series of morphological characters detailed under their respective “Diagnosis.” The concepts of both Denticetopsis and Cetopsis are herein expanded beyond their previous limits to include species formerly assigned to other genera. It proved necessary to place Bathycetopsis , Hemicetopsis , and Pseudocetopsis into the synonymy of Cetopsis in light of the arrived-at scheme of phylogenetic relationships. Such a synonymy is preferable to the alternative of the continued recognition of any, or all, of the nominal genera synonymized herein into Cetopsis , an action that would necessitate the proposal of a series of additional generic names in order that all recognized genera would be monophyletic. The resulting complex generic-level classification would be confusing and more importantly, unnecessarily difficult to utilize given the subtle external differences between some of the clades within Cetopsis .

As discussed by de Pinna & Vari (1995) and de Pinna (1998) the Cetopsinae are diagnosed by a series of internal and external synapomorphies. Most of these features, most notably the internal characters are not, however, applicable to the problem of the rapid recognition of specimens as members of that subfamily. Externally the species of the Cetopsinae are distinguished from other taxa in the Siluriformes by the combination of their lack of an adipose fin, the absence of bony plates on the body, the proportionally-elongate base of the anal fin, the absence of nasal barbels, and the relatively extensive integumentary layer covering the eye when that organ is present.

In order to facilitate cross-reference between the species accounts in this paper, we arrange the genera, and the species within genera, alphabetically.