In brief, these considerations can be summarised by one practical questioning: “should we feed the fish or the tank?” which in turn, requires examining the interactions between fish density, feeding level and prey density (per volume unit), and their consequences on fish survival, growth, size heterogeneity and food conversion. The present study was designed to investigate this issue in larvae of the
catfish Pangasianodon hypophthalmus (Sauvage, 1878) (Siluriformes, Pangasiidae; formerly Pangasius sutchi or Pangasius hypophthalmus). Pangasiid production in aquaculture in 2007 exceeded 1 million tons per year (Lazard et al., 2009). It relies essentially on the culture of P. hypophthalmus, which originates from the Mekong and Tchao Praya river basins, but has been introduced throughout South-East Asia. Larvae of this species reputedly exhibit an intense cannibalistic behaviour at an early age (about 36 h after hatching; Subagja et al., 1999), so the issues of fish density and feeding strategy are crucial to define appropriate rearing strategies in respect to local production constraints in terms of fish survival, growth and food conversion.