Interannual changes in the condition of branquinha cascuda Psectrogaster amazonica Eigenmann & Eigenmann 1889 (Characiformes: Curimatidae) in the Madeira River Marina Granai, Marcela Roquetti Velludo, Alexandre Sorókin Marçal, Paulo Emilio Costa Santos, Ursulla Pereira Souza

Abstract

Psectrogaster amazonica is an important protein source for riverside populations in the Madeira River basin. The species' welfare, from 2009 to 2019, was evaluated using the relative condition factor (Kn). A total of 1,251 individuals (771 females and 480 males) were collected. Differences in the length-weight relationship between sexes were estimated through linear regression. Kn was calculated separately for each sex. Females exhibited positive allometric growth, while males showed negative allometric growth. There was no difference in Kn between sexes. Kn was lower from 2016 to 2018, possibly as a consequence of the 2014 flood, the largest ever recorded.