Tilapia (Oreochromis spp.) is the second most farmed fish globally. Different strains of tilapia have been developed through selective breeding programs over the years to optimise its three main performance traits: growth rate, hardiness and marketability. Of all the strains developed, the most popular is the red hybrid tilapia (O. urolepis female was crossed with a red-gold male O. mossambicus), which was developed to improve the aforementioned traits under commercial production conditions. An emerging strain of the O. aureus crossed with O. niloticus tilapia with a white colour was also developed to enhance both growth and marketability.
This comparative study assessed the growth and physiological potential of the fish and the consumer response to the two tilapia strains (red hybrid and white hybrid- O. aureus X O. niloticus) in the Bahamas. The growth studies were conducted on juvenile (~1.5g) tilapia of both strains. Fish were fed 5% of their body weight daily using commercial tilapia starter feed (40% protein). The fish growth was monitored in weight (g) and total length (mm), and the feed conversion ratio and specific growth rate were calculated. Adult fish (~650g) were used for physiological studies to compare the metabolism and cardiac output of the two strains. Swimming energetic tests were conducted using a water tunnel respirometer set up in the Gamperl Lab, results were collected and compared. When fish had grown to an average of 580g, they were filleted and the ratio of fillet yield to total biomass was calculated. A survey was also conducted to compare the visual and gustatory perception of the two strains both as a whole fish and as a fillet.
The study found that the white hybrid strain exhibited superior growth and physiological performance compared to the red hybrid strain in Bahamian climatic conditions. Notably, the white hybrid strain also boasted a 25% higher fillet yield. Although the red hybrid was visually preferred by Bahamian residents, no significant differences in taste or mouthfeel were observed between the