Abstract
Decapod larvae assemblages were studied in the tropical estuaries off southeastem Brazil (Piraque-a^ii and Piraque-mirim rivers estuaries). A total of 32 taxa of decapod larvae were recorded. Brachyuran larvae dominated in Piraque-a9u estuary, with 62% of the relative abundance, and 49% in Piraque-mirim estuary. Mean larvae concentrations ranged from 17.2 m~(-3) at Piraque-mirim (August 2003) to 221.1 m~(-3) at Piraque-acu (April 2003). The assemblage of larvae in both estuaries was diverse, especially at Piraque-mirim, which showed higher ecological stability. The high spatial heterogeneity of the Piraque-acu and Piraque-mirim estuarine system resulted in the division of the assemblage into two well-defined groups (truly estuarine and euryhaline).Salinity spatial gradient was a key factor in the stmcture and distribution of larvae.
NSTL