Sexual maturation in captive spiny lobsters, Jasus edwardsii, and the relationship of fecundity and larval quality with maternal size

Reproductive and somatic parameters of southern rock lobsters, Jasus edwardsii, held captive since puerulus and wild-caught adults were examined in terms of size at onset of maturity (SOM) and fecundity, culminating in an examination of how adult size may relate to larval competency. The SOM was much smaller in captive animals (62.5 mm carapace length, CL) compared to historical fishery data and indicated that precocious maturation may be induced in captivity. During this study, the fecundity was assessed as the number of viable phyllosoma at hatch, which was ~ 45% of egg estimates from the historical fishery data, suggesting either declining egg numbers in wild stocks over time or that major egg loss occurs during embryonic development. The association between SOM and sexual dimorphism was examined for several morphometric parameters. In females, the SOM was concomitant with increases to the width of the 1st and 2nd abdominal segments above 62.5 mm CL, while 2nd and 3rd leg length increased disproportionately in males compared to females above 77.5 mm CL. There were significant correlations between viable fecundity and female size (r = 0.92), phyllosoma size (r = 0.74) and larval viability as quantified by stress indices (r = -0.56) and LD-50 (r = 0.56), indicating that larger females produce larger, more viable larvae. These physiological traits in larval, juvenile and adult animals may have an impact on fishery and aquaculture production.