Reproductive ecology and growth of marine catfishes (Ariidae) supporting sustainable fisheries in Banc d’Arguin National Park, Mauritania

Abstract

ABSTRACT Marine fish stocks are increasingly being exploited to unsustainable levels. Yet, knowledge of basic biological and ecological traits of species, required to sustain fisheries management at a local scale, remains scarce. We investigated the reproductive biology and growth of two marine catfishes: rough-head sea catfish (Arius latiscutatus) and Guinean sea catfish (Carlarius parkii). Both species showed one spawning season between May and June. Nevertheless, as these are mouth brooding species, we have considered that the reproduction season may be underway until August. Mean fork length of females at first maturity was ∼40 cm for A. latiscutatus and 35 cm for C. parkii, corresponding to 4–5 years for both species. Higher fecundity was found in larger females, with a mean of 45 and 26 eggs for A. latiscutatus and C. parkii, respectively. Differences recorded in sex ratio throughout the year suggest that females can leave the study area after the spawning season or that differences in behaviour may lead to differential sex catchability. The two species showed similar growth curves, despite A. latiscutatus reaching larger lengths at the same age. Estimated length–weight relationships suggest that both species present a positive isometric growth pattern. Our results highlight the slow life-history strategy of the two studied catfish species, thus emphasizing their vulnerability to fishing activities. We suggest that a short-term fishing closure during the spawning period (May–June) in the PNBA may be an important management measure to ensure reproduction opportunities for both species and, therefore, guarantee fishing sustainability.