A new species of the electric fish Microsternarchus Fernández-Yépez 1968 (Gymnotiformes: Hypopomidae) from the lower Amazon basin, Brazil.

A new species of Microsternarchus is described from clear water streams in the lower Rio Amazonas basin, Brazil, increasing the known species in the genus to three. The new species is distinguished from congeners by a unique set of characters including an elongated caudal filament (35.1-36.

Morphological and ecological approaches in reproduction of the endemic catfish of the eastern Amazon.

This study aimed to describe reproductive ecology based on morphological aspects of Peckoltia oligospila in stream rapids, eastern Amazon. A total of 186 fish (75 males and 111 females) were collected. The sex and gonadal maturity stage of these specimens were obtained based on histological characteristics of the gonads.