Abstract
A new species assigned to the genus Trichomycterus from the area of the waterfalls of Tabay stream, Paraná River basin, Misiones, Argentina, is described. Trichomycterus ytororo sp. nov. is distinguished from all other species in the genus by the presence of 31–35 dorsal procurrent caudal-fin rays and the combination of some external characters such as: coloration, number of pectoral–fin rays and pores of the laterosensory canals. The new taxon belongs to a presumably monophyletic group of species composed of T. crassicaudatus, T. igobi, and T. stawiarski based on the presence of 24 or more thickly ossified and rigid procurrent caudal-fin rays with a slender distal tip extending along the tips of at least ten neural spines.
Highlights
Trichomycteridae is a monophyletic group comprising seven monophyletic subfamilies (Copionodontinae, Glanapteryginae, Sarcoglanidinae, Stegophilinae, Trichogeninae, Tridentinae, and Vandelliinae) and the recognized non–monophyletic subfamily Trichomycterinae as presently conceived [1,2,3,4,5]
Among the eight genera of Trichomycterinae, Bullockia Arratia, Chang, Menu-Marque & Rojas, Eremophilus Humboldt, Hatcheria Eigenmann, and Rhizosomichthys Miles, are monotypic based on autapomorphies; Scleronema Eigenmann is a monophyletic group including three psamophyly species; Ituglanis Costa & Bockmann and Silvinichthys Arratia were proposed to allocate species previously included in Trichomycterus Valenciennes; and lastly, Trichomycterus lacks any diagnostic character being demonstrably non-monophyletic assemblage of species [2,3,4,5]
The new taxon exhibits conspicuous characters that indicate a close relationship with T. crassicaudatus Wosiacki & de Pinna, T. igobi Wosiacki & de Pinna, and T. stawiarski (Miranda Ribeiro)
Summary
Trichomycteridae is a monophyletic group comprising seven monophyletic subfamilies (Copionodontinae, Glanapteryginae, Sarcoglanidinae, Stegophilinae, Trichogeninae, Tridentinae, and Vandelliinae) and the recognized non–monophyletic subfamily Trichomycterinae as presently conceived [1,2,3,4,5]. Among the eight genera of Trichomycterinae, Bullockia Arratia, Chang, Menu-Marque & Rojas, Eremophilus Humboldt, Hatcheria Eigenmann, and Rhizosomichthys Miles, are monotypic based on autapomorphies; Scleronema Eigenmann is a monophyletic group including three psamophyly species; Ituglanis Costa & Bockmann and Silvinichthys Arratia were proposed to allocate species previously included in Trichomycterus Valenciennes; and lastly, Trichomycterus lacks any diagnostic character being demonstrably non-monophyletic assemblage of species [2,3,4,5]. Most species inhabit fast-flowing streams [10]. Their range of habitats is remarkably diverse, including unusual freshwater habitats, such as sand-bottom streams, semipermanent pools, high-altitude Andean streams, and desolate creeks in Tierra del Fuego [11]. The new taxon exhibits conspicuous characters that indicate a close relationship with T. crassicaudatus Wosiacki & de Pinna, T. igobi Wosiacki & de Pinna, and T. stawiarski (Miranda Ribeiro)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
