Abstract

Sediment samplings were carried across the intertidal of the beach at Hornitos, northern Chile (22 degrees 26'S) during August and November 1996 and March, July and November 1997 for a study of the reproductive and population biology of Emerita analoga (Stimpson) (Decapoda, Anomura) in a region of the Chilean coast characterized by persistent upwelling. The highest abundances of E. analoga occurred during March and December 1997. During November 1996, March and December 1997, the highest abundances occurred below the effluent line, while in July 1996 and August 1997, most of the stages of E. analoga occurred in higher abundances above the effluent line. Ovigerous females were recorded over the entire study period. Juveniles were also present during all sampling months, peaking during March 1997. Body size of ovigerous females varied between 12.6 and 26.4 mm. Fecundity increased significantly with body size of females in all samples analyzed. The analyses of recruitment pattern for males and females suggest the existence of two pulses in the recruitment of E. analoga at Hornitos: one between October and December, and another one between February and March. Growth analyses show that females have growth rates a maximum body sizes higher than males. Comparisons with similar studies carried out at the coast of south central Chile (ca. 39 degreesS), a region where upwelling occurs occasionally, show that E. analoga from this region have similar growth rates but attain a greater maximum body size than in Hornitos. It is concluded that proximity to areas of persistent upwelling seems not to affect life history of E. analoga in northern Chile.