Otothyropsis, Ribeiro & Carvalho & Melo, 2005

Ribeiro, Alexandre C., Carvalho, Murilo & Melo, Alex L. A., 2005, Description and relationships of Otothyropsis marapoama, a new genus and species of Hypoptopomatine catfish (Siluriformes: Loricariidae) from rio Tietê basin, southeastern Brazil, Neotropical Ichthyology 3 (4), pp. 489-498 : 491

Otothyropsis , new genus

Type species: Otothyropsis marapoama by original designation.

Diagnosis. The clade that includes Otothyropsis , Otothyris and Pseudotothyris differs from the remaining genera of the Hypoptopomatinae by having an elongate posterior extension of the pterotic-supracleithrum which forms the dorsal margin of an enlarged lateral opening of the swimbladder capsule (vs. quadrangular in shape and not extending posteriorly to form the dorsal margin of swimbladder capsule), and by having the supraoccipital forming the dorsal wall of the swimbladder capsule (vs. supraoccipital does not contribute to dorsal wall of swimbladder capsule) (derived states of characters 8 and 12 of Schaefer, 1998). Otothyropsis , however, differs from Pseudotothyris and Otothyris by having enlarged odontodes on the dorsal and ventral margins of the snout (vs. enlarged odontodes only on the dorsal margin); by lacking conspicuous crests of enlarged odontodes on the tip of supraoccipital and pterotic-supracleithrum in adults (vs. adults with well-developed crests), and by having the abdomen completely plated in adults (vs. adults with abdominal platelets reduced, sometimes restricted to lateral abdominal plate series).

The following characters were considered autapomorphic in our reanalysis of Schaefer’s (1998) phylogenetic framework of the Hypoptopomatinae , and phylogenetically diagnoses the new genus Otothyropsis : presence of a single median rostral plate; presence of enlarged odontodes in both dorsal and ventral snout margins (derived conditions of characters, 34 and 39 of Schaefer’s, 1998 phylogeny); and presence of the ocular diverticulum (reversal of character 42 of Schaefer’s, 1998 phylogeny). None of these characters, however, are exclusive to Otothyropsis , being considered homoplasies according to the parsimony analysis.

Etymology. The first part of the name is from Greek (otos = ear and thyris = window) and is in reference to the Hypoptopomatinae genus Otothyris , to which the new taxon is closely related. The second part is from the Greek (opsis = relating to sight and appearance); hence, resembling a hypoptopomatine fish. Gender: feminine.