Tropical mangrove habitats are generally brackish water environments, and have endemic brachyuran species most of which show an ‘exportation’ life cycle strategy (e.g. Dittel et al., 1991; Paula et al. 2000), as found in estuaries in general (Queiroga,1996). Newly-hatched larvae immigrate by passive and active mechanisms to adjacent shelf waters, using selective stream tidal transport (Queiroga et al., 1997; Queiroga, 1998).