Culturing coral larvae with food supplements enhances larval size and settlement

The cultivation of coral larvae in controlled aquaculture systems has the potential to improve survivorship during early life stages and support coral reef restoration efforts. Maximising the health and energy of coral larvae is important for scaling up larval production for recruitment and restoration initiatives. Increasingly, research is focusing on optimising larval rearing practices but larval feeding during ex situ culture remains under explored. Although feeding larvae can enhance settlement in Acropora species, an optimal feeding regime has not yet been determined. Therefore, this research aimed to quantify the effects of supplying different amounts of food on larval survival and settlement of Acropora cf. kenti larvae. Larvae were reared in 14L culture tanks and exposed daily to one of three doses of homogenised Artemia (5mL, 50mL, or 100mL) and an unfed control of no Artemia. Larval survival, larval size, settlement, and size of settlers were measured. There was a significant positive effect of feeding on settlement for medium (50mL) and high doses (100mL) of homogenised Artemia, resulting in a 2.5-fold increase in settlement compared with unfed larvae. Further, feeding medium and high doses of food significantly increased the size of larvae and settlers. However, feeding did not significantly affect survival. Understanding the biological parameters influencing larval nutrition and settlement can refine aquaculture methodologies for scaling up restoration initiatives.