Factors influencing fecundity and population egg production of Jasus species
John H. Annala
Abstract
The influences of body size, gonad size, egg size, size at onset of maturity, growth rate, and water temperature on fecundity and population egg production for seven species in the spiny or rock lobster genus, Jasus, were examined. The relationship between fecundity and body size was curvilinear for most species, with the slope of the curve generally decreasing at larger body sizes. For J. edwardsii total egg weight was almost directly proportional to gonad weight. Size at onset of maturity varied widely between species, from 56 mm carapace length for J. lalandii to 155-159 mm carapace length for J. verreauxi. For J. edwardsii there was an inverse relationship between size at onset of maturity and water temperature, while for J. lalandii differences in size at onset of maturity were unrelated to water temperature. There was a negative relationship between fecundity and size at onset of maturity for J. edwardsii, perhaps caused by smaller gonad sizes of large individuals in areas where size at maturity is large. Fecundity of J. lalandii was lower in areas where growth rate was slower. Population egg production of J. edwardsii was positively related to fecundity, but negatively related to size at onset of maturity.