Sizes at first maturity and at onset of breeding in female Jasus verreauxi (Decapoda: Palinuridae) from New South Wales waters, Australia

Abstract

Two criteria were used to investigate the size at which female eastern rock lobsters (Jasus verreauxi) off New South Wales attain maturity. These were the presence of well developed setae on, or the presence of eggs attached to, the pleopods. Females having well developed setae on the pleopods and/or carrying eggs were found only in catches from Coffs Harbour and Crowdy Head, the two most northern localities sampled. There were no significant differences in carapace length (CL) between size at first maturity (SOM) and size at onset of breeding (SOB) within or between areas sampled or when data from different areas were combined. SOM and SOB values (with 95% confidence intervals) for combined areas were, respectively 170.1 mm CL (169.1-171 a2 mm CL) and 166.5 mm CL (166.1- 171.9 mm CL). The present legal minimum length for harvesting J. verreauxi (104 mm CL) is far shorter than these SOM and SOB values. It is suggested that if a legal minimum length is imposed to conserve the spawning stock, then it should be 166 mm CL.