7. Fish in aquaponics
The first section in this chapter includes select information on fish anatomy and physiology, including how they breathe, digest food and excrete wastes. The feed conversion ratio (FCR) is introduced, important for all aquaculture, which refers to how efficiently the fish convert feed into body mass. Special attention is then devoted to the fish life cycle and reproduction as it relates to breeding and maintaining stocks. The care and health of fish in aquaponic units are then discussed, covering water quality, oxygen, temperature, light and nutrition. The third section identifies a number of suitable commercial aquatic species for aquaponics, focusing on tilapia, carp, catfish, trout, bass and prawns (Figure 7.1).
The chapter closes with a final section on individual fish heath, diseases and disease prevention methods.
FIGURE 7.1
Tilapia juveniles (a) and adults (b) growing in an aquaponic unit