Predatory activity and spatial strategies of Epixanthus dentatus (Decapoda, Oziidae): an ambush predator among the mangroves.

The predatory patterns and spatial strategies of Epixanthus dentatus were studied in a mangrove creek on the Kenyan coast, together with laboratory analysis aimed at assessing the natural diet. This xanthoid fed on almost all the slowly moving invertebrates common in the forest and actively preyed at night, using an ambush technique. Epixanthus dentatus is faithful to individual dens among the roots and to well-defined feeding areas within a 3-m radius, which they shared with an average of 2 other individuals. The high density of E. dentatus seemed to affect the behavior of major prey species; various grapsid crab species reduced their climbing activity during the peak activity peri- ods of E. dentatus. The density of E. dentatus among the mangrove roots was determined both by the number of suitable dens, and, more directly, by the density of prey species.