Systematics of Pseudotothyris

[Silurus]

Martins, FO, HA Britski & F Langeani, 2014. Systematics of Pseudotothyris (Loricariidae: Hypoptopomatinae). Zoological Journal of the Linnean Society 170: 822–874.

Abstract

Pseudotothyris Britski & Garavello, 1984 is a genus of small catfishes distributed only in coastal basins in southern and south-eastern Brazil, between Rio de Janeiro and Santa Catarina states. Schaefer (1991), in a phylogenetic analysis of the Hypoptopomatinae, did not find any uniquely derived character to diagnose Pseudotothyris, and thus questioned its taxonomic validity, suggesting that a more detailed comparative analysis would be necessary to find exclusive diagnostic characters of the genus. Based on this, the present study aimed to perform a phylogenetic analysis and taxonomic revision of the genus, evaluating its specific composition, its monophyly, and its phylogenetic relationships. For this, we performed a phylogenetic analysis with 92 characters observed across 57 terminal taxa, including members of the Delturinae, Loricariinae, Hypostominae, Neoplecostominae, and all valid genera of Hypoptopomatinae. Our results corroborate the monophyly of the genus, which is supported by a uniquely derived synapomorphy: anterior snout odontodes well developed only on dorsal region. As expected and already suggested by other authors, Pseudotothyris is recovered as the sister group of Otothyris, another genus that occurs in coastal drainages. Additionally, as a result of the taxonomic revision, we present a redescription of the genus and of the two valid species, and the description of a new species.