Feeding behaviour of broodstock Penaeus monodon fed live and frozen polychaetes

Hatchery production of Penaeus monodon larvae is dependent on the optimal management of broodstocks. Promoting gonadal maturation of wild-caught broodstock in captivity requires refined husbandry practices and nutritional fortification to achieve satisfactory reproductive outcomes. Understanding feeding behaviour is necessary to promote optimal feeding strategies. Marine polychaetes are a widely used primary feed item due to their nutritional profile. However, live polychaetes are not always readily available, and frozen polychaetes are fed instead. The behavioural responses of adult P. monodon to live versus frozen polychaetes are unknown. The present study investigated behavioural responses of individually-held male P. monodon broodstock (n = 18) to live or frozen Nereid polychaetes Perinereis helleri through infrared videography observation across 48 h. Three separate feeding events were observed continuously for 2 h (14:30 h, 07:30 h, and 14:30 h), whereby prawns received either live or frozen polychaetes for Feeding Events 1 and 2 (n = 9 per treatment) and a combination of both for Feeding Event 3. Not all prawns were observed to feed at each feeding event. No significant differences in behaviours were evident between feed types (all P ≥ 0.38) nor was a preference for live or frozen polychaetes displayed through latency to eat, number of interactions with feed, nor time spent feeding (all P ≥ 0.31). These findings suggest that male broodstock prawns are non-discriminatory feeders, showing no preference between live and frozen polychaetes. While it remains possible that live polychaetes may confer reproductive advantages, the present study found no evidence that such benefits in male prawns are linked to differences in feeding behaviour associated with the types of polychaetes. Further studies with a larger sample size as well as focusing on female prawns are recommended.