Analysis of the relationship between relative abundance of mature, impregnated females of Pleoticus muelleri (Bate, 1888) (Crustacea, Decapoda) and environmental variables through statistical models
The relationship between the relative abundance of mature and impregnated females of the Argentine red shrimp Pleoticus muelleri (Bate 1888) and environmental variables was analyzed using statistical methods. Analyzed data carne from the research cruises of the Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) carned out durmg January 2000, 2001, 2005, and 2007; March 2006; and November 2004, 2005, and 2006 in San Jorge Gulf (Argentina). The biological variables considered were the relative abundances of mature and impregnated female shrimp, whereas the environmental variables corresponded to depth, bottom water temperature and salinity, and the difference between surface and bottom water temperature and salinity. Generalized additive models were used as an exploratory tool for the numerical data and the general linear models as a confirmatory tool. The results showed that the distributions and abundances of mature and impregnated females were related to the bottom water temperature and salinity and to depth. The relationship increased along with temperature; with salinity, however, it decreased for mature females and increased for impregnated females. An optimal depth range was evidenced, where the largest concentrations of these individuáis were located.