Length‐weight relationship and condition factor of 11 fish species of the Igarapé Fortaleza basin, a tributary from the Amazon River system in eastern Amazon (Brazil)

The present study investigated the length‐weight relationship (LWR) and allometric condition factor for 11 freshwater fish species of the Igarape Fortaleza basin (00°02037.5″N; 51°06019.2″W), a tributary from the Amazon River system in the State of Amapa, northern Brazil. The fish were collected in the period from 2012 to 2014 using gillnets with different mesh sizes (10–40 mm between opposite knots). LWR parameters were estimated had angular coefficient (b) varying from 2.055 to 3.158. The allometric condition factor presented interspecific variation. These data complement the efforts to understand the biology of these Amazonian fish species.