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Uzeda, P. L. C. et al 2026 (4)

Abstract: Four new species of the small-sized armoured catfish genus Pareiorhina are describedf rom mountain ranges in the Grande River drainage, upper Paraná River basin, basedon morphological and molecular species delimitation methods. Molecular analyses based on the cytochrome oxidase subunit I (COI) marker recovered Pareiorhina aspolyphyletic, with none of the 11 nominal species, including the 4 newly described,forming a clade with the type species Pareiorhina rudolphi. Instead, two sister clades were recovered outside P. rudolphi: one comprising species with a postdorsal ridgeand unicuspid teeth, and another lacking the ridge and bearing bicuspid teeth. The four new species resemble Pareiorhina carrancas and Pareiorhina hyptiorhachis, both readily distinguished by the presence of a postdorsal ridge and simple teeth, and differ from all congeners by unique combinations of body colouration, abdominal plating, vertebral counts, pelvic girdle morphology and morphometric traits. These results underscore the underestimated diversity of the upper Paraná River basin and reinforce the need for continued ichthyofaunal surveys. Furthermore, they highlight the importance of integrating morphological and molecular data to unravel species diversity and distribution patterns of small sized fish species inhabiting southeastern Brazilian headwaters (Uzeda P. L. C. et al 2026). Habitat: P. isabelae is known from three unnamed streams within the Ribeirão Itaci microbasin, Sapucaí River drainage, Grande River, upper Paraná River basin (Uzeda P. L. C. et al 2026). Diet: A herbivorous species that feeds mainly on periphyton (benthic autotrophs composed of microalgae that grow on a substrate). Reproduction: Regarding reproduction, spawning occurs between October and February, with the cycle being completed in April (Braga and Andrade 2005). Etymology: The specific epithet ‘isabelae’ honours Isabel Cristina de Azevedo Santos, mother of VMA-S, who first introduced him to fishing. Isabel Cristina provided essential logistical support during the collection of this and other recently described fish species in the municipalities of Carmo do Rio Claro and Conceição da Aparecida, Minas Gerais State, Brazil. It is a noun in the genitive case.

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Loricariidae

South America: Three unnamed streams within the Ribeirão Itaci microbasin, Sapucaí River drainage, Grande River, upper Paraná River basin.

4.0cm. (1¾ins)

21-25°c (69-77°f)

6.5-7.5.

Fish in the News 2026.
Uzeda, P. L. C., Sartori, L. J., Katz, A. M., Ottoni, F. P., Costa, W. J. E. M., Langeani, F., & Azevedo-Santos, V. M. (2026). Integrative taxonomy reveals four new species of the armoured catfish genus Pareiorhina (Siluriformes: Loricariidae) from the upper Paraná River basin, Brazil. Journal of Fish Biology, 1–28.