Partial inclusion of macroalgae into formulated feed to induce gonad maturation in tropical abalone, Haliotis squamata, broodstock

The reproductive performance of tropical abalone is crucial for sustainable aquaculture practices, particularly in improving broodstock management strategies. This study evaluated the reproductive performance of tropical abalone (Haliotis squamata) broodstock, induced by feeding them formulated feed containing macroalgae as one of its protein sources. The experimental broodstock specimens were fed a formulated diet consisting of a combination of three macroalgae species: Gracillaria sp., Ulva sp., and Sargassum sp., with increasing protein levels (30, 35, 40, and 45%). The broodstocks were reared in a flow-through water system and fed the respective diet twice a day (5 AM and 8 PM). The gonad maturity level, gonad somatic index, fecundity, and hatching rate were measured at the end of the experiment. This study indicates that the gonad somatic index, fecundity, and hatching rate of the eggs were significantly influenced by the protein level of the diet, with higher values being obtained from the broodstock fed with high protein diets (40-45% crude protein). However, the gonad maturity level showed no difference across all treatments. This study suggests that broodstock reproductive performance can be improved by feeding them a high protein diet with macroalgae as one of the protein sources.