Partial replacement of commercial fish meal with Amazon sailfin catfish Pterygoplichthys pardalis meal in diets for juvenile Mekong giant catfish Pangasianodon gigas

Aquatic resources in Thailand have been affected by the introduction of Amazon sailfin catfish, Pterygoplichthys pardalis. This species has had a negative impact on native fish and has not been caught and consumed widely. At present there is debate as to whether it will be best to remove them from natural water sources or find some way to gain benefits from the presence of this species in Thailand. This research was conducted to evaluate the possibility of replacing standard fish meal with P. pardalis meal in the diets of juvenile Mekong giant catfish, Pangasianodon gigas. Five diets with replacement levels of 0% (control), 25%, 50%, 75% and 100% were tested for 90 days. The results showed that the weight gain (WG), average daily growth rate (ADG), specific growth rate (SGR), feed conversion rate (FCR), feed efficiency (FE) and protein efficiency ratio (PER) were not significantly different when compared with the control group. In none of the groups mortality occurred. Moreover, serum biochemistry indices such as levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose, albumin, globulin, protein, triglyceride and cholesterol were not significantly different from the control group (ANOVA, p > 0.05). Based on our results, we conclude that commercial fish meal can be replaced with P. pardalis meal to make up 100% of the diet of P. gigas without producing any adverse effects on growth performance, feed utilization and serum biochemical indices. Keywords: Aquaculture, Fish meal replacement, Formulated feed, Growth performance, Serum biochemistr