Isbrueckerichthys Derijst

Fernando C. Jerep, Oscar A. Shibatta, Edson H. L. Pereira & Osvaldo T. Oyakawa, 2006, Two new species of Isbrueckerichthys Derijst, 1996 (Siluriformes: Loricariidae) from the rio Paranapanema basin, Brazil., Zootaxa 1372, pp. 53-68 : 53-54

[[ Genus Isbrueckerichthys Derijst ]]

The genus Isbrueckerichthys was proposed by Derijst (1996) to include the species Pareiorhaphis duseni (Miranda Ribeiro, 1907) and Pareiorhaphis alipionis Gosline, 1947 . This proposal was justified based on the discovery of an earlier type-species designation by Regan (1920), which had fixed Hemipsilichthys calmoni Steindachner, 1907 as the type species of genus Pareiorhaphis , making Pareiorhaphis a synonym of Hemipsilichthys and dislocating P. duseni and P. alipionis , once they do not fit in the new designation (sensu Derijst 1996).

Isbrueckerichthys is composed of small- to medium-sized species (up to 90.2 mm SL) of loricariids (suckermouth armored catfishes). Although a phylogenetic diagnosis for Isbrueckerichthys is until now unavailable, this genus is distinguished from other neoplecostomines by a combination of characters: small naked area behind the pteroticsupracleithrum, abdomen with small platelets embedded in skin between pectoral girdle and pelvic-fin insertions, dorsal fin with one spine and seven branched rays, caudal peduncle ovoid in cross-section and lacking a series of papillae on the lower lip of the dentaries. Species of this genus are commonly found in small to medium headwater streams with clear, fast running, and well-oxygenated water, where the bottom is composed of rocks, boulders, and sometimes gravel (Pereira & Reis 2002).

The three described species of Isbrueckerichthys are recognized and thought to be endemic to the rio Ribeira de Iguape basin: Isbrueckerichthys duseni (Miranda Ribeiro, 1907) from the upper reaches of that basin in Paraná State, I. alipionis (Gosline, 1947) , from the rio Betari, a tributary of rio Ribeira de Iguape and I. epakmos Pereira & Oyakawa, 2003 from a tributary of the rio Juquiá in São Paulo State.

In the present paper two new species of Isbrueckerichthys are described, both of them collected in headwater streams of rio Tibagi, rio Paranapanema basin, in Paraná State, Brazil. These species represent the first Isbrueckerichthys species in the Paraná River basin and an increase in the geographic distribution range of the genus.