Growth and survival of the abalone Haliotis asinina fed seaweed Gracilariopsis heteroclada, formulated diet, and a combination of both

This paper compares the effect of feeding the abalone Haliotis asinina with seaweed (SW), formulated (FD), and mixed (SW + FD) diets. The feeding experiment, in six replicates, was conducted in a tank facility and lasted for ten months. At the end of the experiment, abalone fed mixed diets had significantly the highest mean shell length and body weight (45.90 ± 0.19 mm, 22.82 ± 0.31 g), followed by those fed seaweeds (43.47 ± 0.17 mm, 18.25 ± 0.26 g), and lastly, by those fed formulated diet (41.78 ± 0.18 mm, 15.76 ± 0.22 g). Mean growth rates were significantly higher when abalone were fed with mixed diets at 1.48 ± 0.03 mm and 1.69 ± 0.04 g mo − 1 , respectively, than those fed seaweeds (1.26 ± 0.03 mm, 1.27 ± 0.06 g mo − 1 ) or formulated diet (1.06 ± 0.09 mm, 1.00 ± 0.11 g mo − 1 ). Survival was consistent one month from the start of culture until harvest—highest in abalone fed mixed diets (78.81 ± 2.48%), followed by those fed seaweeds (70.12 ± 4.07%), and lastly formulated diet (64.53 ± 4.61%). Moreover, feed conversion ratios (FCR) were significantly lower in abalone fed mixed diets (15.48 ± 0.69) and formulated diet (18.07 ± 3.50) compared with those fed seaweeds (41.31 ± 2.36). Pearson correlation analysis did not show any correlation between growth rates and the environmental variables tested, except for survival in all treatment diets, which showed significantly moderate positive correlations with temperature. Based on the results of this experiment, giving abalone a mix of formulated and natural diets is the best feeding regime. The importance of a balanced and more nutritional diet on the well-being of the abalone was observed in this study.