Paradigm to complex ecosystems: competitive interactions between corals and acanthaster planci predation

The presence of corallivore Acanthaster planci is most threatening to the coral reef ecosystems and worldwide most of the reports state that its aggressive feeding behavior degrades the life forms of coral reefs in the last few decades. However, its selective feeding behavior is only on Pavona sp. which indirectly helps to recover the long-lived massive forms of Porites sp. in the Lakshadweep atoll, Kavaratti lagoon corals. Benthic survey results reveal the reason behind this selective feeding by Acanthaster planci on Pavono sp. because of the single species (Pavona sp.) domination occuring via competitive interactions among the coral colonies. Observations clearly show that the higher competitive interactions (26.8%) among corals results in higher mortality (53.5%) of corals by the Acanthaster planci. The predation compensate the loss of species diversity due to dominating competitive interactions in the coral reef ecosystem, which is evidenced by the predation prey mediation analysis and the results indicate that the recovery level of Porites sp. against Pavona sp. is 0.785. This selective predation regulates the coral reef ecosystem as a balanced one by the crown of thorn starfish Acanthaster planci in Kavaratti lagoon corals.