Are infestations of Cymo melanodactylus killing Acropora cytherea in the Chagos archipelago?

Abstract

[Extract] Acropora cytherea is commonly dominant between 5 and 15 m depth at moderately exposed locations throughout Chagos. At several locations visited in February 2010, approximately 5% of these colonies had conspicuous evidence of recent tissue loss (Fig. 2).

Given the high densities of C. melanodactylus and their proximity to the dead tissue front, it seems that these crabs may be causing or contributing to observed coral mortality. Alternatively, these corals may be dying due to other causes (e.g., coral disease) and like many other corallivores (e.g., McIlwain and Jones 1997), C. melanodactylus may feed selectively on injured corals.