“…Genidens genidens (Cuvier, 1829) is one of the most abundant species in estuarine systems off Brazilian coast (Andrade-Tubino et al, 2008;Schmidt et al, 2008), occurring on the eastern coast of South America, from Bahia (Brazil) to Buenos Aires (Argentina), inhabiting shallow coastal waters, estuaries and lagoons (Fischer et al, 2011). This catfish has a peculiar reproductive biology, where females produce large oocytes and males carry out oral incubation of the offspring, with the reproductive period occurring once a year during the hot months, from late spring to early autumn (Maciel et al, 2018a;Wallace and Selman, 1981). Although G. genidens is an important commercial species for artisanal fishery (Silva-Junior et al, 2013), its population structure and life history are not well known, and the few existing management policies aimed at this resource are restricted only to a few regions (MMA, 2004;SUDEPE, 1984).…”