Abundance and Ecological Distribution of the Sete-Barbas Shrimp Xiphopenaeus kroyeri (Heller, 1862) (Decapoda: Penaeoidea) in Three Bays of the Ubatuba Region, Southeastern Brazil

The influence of environmental factors on the abundance and spatial-temporal distribution of the shrimp Xiphopenaeus kroyeri was investigated in southeastern Brazil over 2 years. Monthly collections were conducted in Mar Virado, Ubatuba and Ubatumirim Bays using a commercial shrimp fishing boat equipped with 2 double-rig nets. Each bay was divided into 6 sampling stations, all of which were less than 25 m deep. The spatial distribution of X. kroyeri differed among Bays. Highest abundance values were recorded in areas where silt and clay comprised more than 70% of the bottom sediment. Abundance of X. kroyeri followed a seasonal trend, being higher during fall and winter, when intrusions of tropical waters are frequent, causing an increase in salinity (\u3e 35‰) and temperature (\u3e 21° C). A clear decrease in shrimp abundance followed a decrease in bottom temperature (\u3c 20° C) during spring and summer due to the influence of cold water currents, particularly the South Atlantic Central Water. These results suggest that sediment type, salinity, and temperature are among the most important variables affecting the spatial and seasonal distribution of this species