Laboratory study on the relative predation rates of crown-of-thorns starfish (CoTS) larvae by five fish species
摘要
Crown-of-thorns starfish (CoTS) pose a significant threat to coral reefs due to their predatory habits and high reproductive capacity, often resulting in population surges and outbreaks. Although manual removal of adult starfish is currently the primary control method, planktivorous fish may also play an important role in regulating the CoTS population. An increasing number of fishes have been identified as predators of CoTS, but the key fish predators and their predation characteristics are not yet known. In this study, we evaluated the predation potential of five fish species on CoTS larvae, including Chaetodon auripes, Arothron hispidus, Ostorhinchus taeniophorus, Amphiprion ocellaris, and Lates calcarifer. The results show that the oriental butterflyfish (C. auripes) had the highest consumption rate (69.9 ± 3.0 larvae h−1), and there was no significant difference among the consumption rates of the other four fish species, although O. taeniophorus had the lowest predation rate (11.9 ± 14.3 larvae h−1) on CoTS larvae. The predation rate of the oriental butterflyfish on CoTS larvae increased with CoTS larval density and feeding time, peaking at 164.00 ± 52.57 larvae h−1 at a larval density of 200 larvae L−1, and predation for 120 min resulted in a significantly higher consumption, which did not differ among the other three times (10 min, 30 min and 60 min). Furthermore, butterflyfish predation on CoTS larvae was not influenced by larval developmental stage or the presence of the alternative food source, Artemia. These results emphasize the effectiveness of butterflyfish as a predator of CoTS larvae and their potential to play a crucial role in CoTS population management.