A new species of inseminating catfish of the genus <i>Tympanopleura</i> (Siluriformes: Auchenipteridae) from the Ituxi River, Amazon River basin, northern Brazil, revealed by integrative taxonomy

A new species of the genus Tympanopleura is described from the Iquiri River, a tributary of the Ituxi River, a right-bank tributary to the Purus River, Amazon River, northern Brazil. The new species is distinguished from all its congeners by a combination of features, such as the presence of an intensely pigmented square-shaped blotch on the supraoccipital, a semicircular dark blotch above each eye and an inconspicuous vertical bar on the caudal-fin base (except Tympanopleura piperata), and by a combination of meristic and morphometric character states. Preliminary molecular analyses demonstrate genetic distance values of 2.4% of cytochrome oxidase, subunit I, divergence between the new species and T. piperata and 8.0%-13.0% between the new species and the other congeners. The new species shows several reproductive adaptations to copulation and internal insemination. Considering the period during which prenuptial and nuptial specimens were available, we can presume that its reproductive period occurs when the water level increases. In addition, an identification key for the species of Tympanopleura is provided.