The planktonic copepod community at Mahahual Reef, western Caribbean

The species composition, distribution, and abundance of the copepods collected during a 4-d zooplankton survey across a Mahahual coral reef system of the Mexican Caribbean Sea were studied. Highest mean copepod abundance and diversity were observed in the fore-reef in daytime samples. Lowest abundances occurred in the reef lagoon and channel at daytime. Forty-five species were identified, with Temora turbinata, Undinula vulgaris, Subeucalanus subcrassus, and Calanopia americana as the most abundant. They belong to a group of planktonic copepods dominant in the Caribbean reefs. Cluster analysis revealed a primary (fore-reef) and secondary (reef lagoon, channel) oceanic group, showing the strong oceanic influence across the reef system which was attributed to the narrowness of the shelf and the effect of tidal currents and other hydrological features. Overall day-night differences were related to the influence of near-benthic migrating forms. Acartia spinata, an abundant reef lagoon species in the Caribbean, was scarce at Mahahual due to its breeding cycle. Its scarcity may be correlated with the relatively high diversity in the reef lagoon, an oceanic predominance in the reef system, and relatively low overall copepod densities. The main features of the copepod community at Mahahual are similar to those found in other regional reef systems.