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

Abstract

Paulo, BraziL Emailfransozo@ibb.IlI.U) Yp.br ABSTRACTThe influence of environmental factors on the abundance and spatial-tempotal distribution of the sltrimp Xiphopenaeus kroyeri was investigated. in southeastern Brazil over 2 years. Monthly collections were conducted in Mar Vrrado, Dbatuba and Dbatumi!im Bays using a commercial shrimp fishing boat equipped with 2 "doubJe.-rig" nets. Each bay was divided into 6 samplJng 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, heing higher during fall and winter, when intrusions of tropical waters are frequent, causing an increase in salinity (> 35%") and temperature (> 21° C). A clear decrease in shrimp abundance followed a decrease in bottom temperature « 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 affeclJng the spatial and seasonal distribution of this species.

Abundance and spatial-temporal distribution of the shrimp Xiphopenaeus kroyeri (Decapoda: Penaeidae): an exploited species in southeast Brazil

“…In the study by Nakagaki and Negreiros-Fransozo (1998) was also observed variations in the abundance of this species due to greater penetration of SACW in regions closer to the coast. Similar results were observed by Fransozo et al (2002) and Costa et al (2007) for X. kroyeri, everyone conducted in Ubatuba, northern coast of São Paulo state.…”

“…Several authors have suggested that penaeoid shrimp distribution is strongly modulated by the texture and organic content of the substrate (Rulifson, 1981;Dall et al, 1990;Sanchez, 1997;Costa et al 2007). Our results contradict these assertions since no correlation was found between X. kroyeri and texture of the sediment, and a negative correlation was observed between their abundance and organic matter content of the substrate.…”

“…This result also supports the conclusion that the species has a great plasticity in relation to sediment type. Other studies such as those developed in Ubatuba, São Paulo State (Freire et al, 2011;Costa et al, 2007) found that this species prefers muddy sediments, which in this study area occurred in shallower portions.…”

“…Our results contradict these assertions since no correlation was found between X. kroyeri and texture of the sediment, and a negative correlation was observed between their abundance and organic matter content of the substrate. A possible hypothesis is that this result is a reflection of the high catch of X. kroyeri in the shallower areas where the organic matter content is low; this shrimp species occurs at temperatures above 21°C (Costa et al, 2007) and in the present study area, stations with predominantly muddy sediments showed lower temperature than 21°C.This leads to assume that the temperature in these areas is the primary factor in the establishment of individuals of this species.…”

“…Ecological studies concerning crustaceans were conducted in southeastern Brazil (Fransozo et al, 2002;Castro et al, 2005;Costa et al, 2007Costa et al, , 2011Almeida et al 2012b;Heckler et al, 2013;Silva, 2013), principally on the coast of São Paulo. However, they are scarce on the coast of Rio de Janeiro, especially on the study region, Santana Archipelago, in Macaé (RJ).…”