Vitamin Requirements of Blue Tilapias in a Recirculating Water System

Abstract

Abstract Fingerling blue tilapias (Tilapia aurea) were offered vitamin-complete semipurified diets supplemented with different levels of either pantothenic acid or choline during three studies. A vitamin-free control diet was included in one study. Fish were kept in aquaria and supplied with recirculated water from a downflow gravel filter. No differences in weight gain, survival, or feed utilization were detected among fish in the different treatments, except for fish fed the vitamin-free diet. Those fish became lethargic and anorexic, lost equilibrium, developed hemorrhagic areas in the skin and fins, and exhibited poor growth and low survival. It is suggested by the results of this study that tilapias could satisfy their requirement for pantothenic acid, choline, and possibly other (but not all) vitamins by feeding on bacteria in a recirculating system.