Development, nutrition, and rearing practices of relevant catfish species (Siluriformes) at early stages

Catfish (Siluriformes) are important species for aquaculture worldwide, with an annual production in 2018 of ca. 6 million t. This review focuses on reassessing larval development, first feeding, and early rearing practices of the most important farmed catfish species, along with some candidate species for aquaculture diversification: Pangasianodon hypophthalmus (Pangasiidae), Clarias gariepinus (Clariidae), Ictalurus punctatus (Ictaluridae), Pseudoplatystoma spp. (Pimelodidae), Heteropneustes fossilis (Heteropneustidae), Rhamdia quelen (Heptapteridae), Ompok bimaculatus (Siluridae), and Lophiosilurus alexandri (Pseudopimelodidade). These species are initially reared indoors from one day to two weeks and are then transferred to fertilised outdoor ponds where they either feed on natural zooplankton or compound feeds. With the exception of C. gariepinus, I. punctatus, R. quelen and P. hypophthalmus, consistent and reliable fry production is a bottleneck that limits the expansion of farming of other species, such as Pseudoplatystoma spp., H. fossilis, O. bimaculatus, and L. alexandri. Rearing systems (extensive, semi-extensive, intensive) and feeding protocols vary with species and geographical regions. Cannibalism and size heterogeneity are common, and these features create problems for larval and fry rearing of catfish species. Information about their nutritional requirements is required for the formulation of compound feeds that can guarantee high survival and good growth of catfish fries. However, such knowledge for most species is scarce, although some data are available for I. punctatus. Further genomic resources might allow fine-tuning rearing success. This review describes some successes in this field, and also highlights gaps in knowledge to guide future research that can promote the development of catfish aquaculture.