Fecundity and sex ratio of Panulirus inflatus in the west coast of the Gulf of California, Mexico

The fecundity and sex ratio of P. inflatus were studied in the western coast of the Gulf of California, Mexico. From February 2004 to January 2005, 567 lobsters were captured, 302 males (M) and 265 females (F). The sex ratio was 1H:1.13 M which did not differ significantly from 1:1. Fecundity varied between 94,837 and 830,149 eggs (384,314 +/- 162,147, mean +/- SD, n = 97). On average, the relative fecundity was 952 +/- 222 eggs g(-1). The Index of Reproductive Potential (IRP) showed that females with cephalotorax length (CL) smaller than 80 mm contributed with 10.82% of the eggs' production, probably because of their low fecundity and spawn only two times during the reproductive season. On the other hand, females between 80 and 110 mm CL contributed with 80.23% of the spawned eggs. These females had a high fecundity, potentially spawn up to four times during the reproductive season, and presented high frequencies of occurrence in the samples. Although females larger than 110 mm CL had a high fecundity (around 800 thousand eggs), and may spawn up to four times during the reproductive season, their contribution in eggs is low, 10.55%, probably because they are not abundant in the population.