Utilization of bating mangrove leaves as a transport mechanism of estuarine organisms, with emphasis on decapod Crustacea

Abstract

Floating mangrove leaves with associated organisms were sampled approximately every 2 h over 4 consecutive tidal cycles from 1 to 3 December 1987 in the estuary of Punta Morales, Gulf of Nicoya, Costa Rica. Crabs were the predominant animals collected (77.8 %), followed by shrimps, fishes and other crustaceans. The 4 most abundant decapod crustacean taxa found attached to the leaves were Uca, Callinectes, Penaeus and Macrobrachium. Megalopal and juvenile stages of decapods, clingfish Tomlcodon sp., as well as amphipods and isopods, were attached to the drifting leaves. Organisms were significantly more numerous during flood than ebb: mean total number of individuals per leaf was one order of magnitude greater during incoming than during outgolng tide (2 3 versus 0.1) This transport mechanism may minimize both the risk of predation and the energy required to immigrate into the preferred habitat. This strategy may be important for recruitment of crabs and shrimps in mangrove ecosystems.