JH Annala; JL McKoy; JD Booth; RB Pike
The size at the onset of sexual maturity for female rock lobsters, Jasus edwardsii, was defined as the size or size class at which 50% of the rock lobsters in a sample were mature, and was estimated at 27 localities around New Zealand. Animals were regarded as mature if they were bearing external eggs attached to the pleopods or if there were well developed setae on the endopodites of the pleopods. Samples from the same location in different years showed little variation in the size at the onset of maturity. There was, however, considerable variation between localities, ranging from 72 mm carapace length near Gisborne to 121 mm carapace length in eastern Foveaux Strait. Size at the onset of maturity showed an inverse relationship with water temperature. The relationship between the size at the onset of maturity, age, growth rate, and water temperature is discussed.