Longevity, reproductive condition and growth of the western rock lobster, Panulirus cygnus george, reared in aquaria

Abstract

Rock lobsters have been reared in the laboratory from the puerulus stage up to 13 years of age, under conditions of a constant temperature of 25ºC or ambient temperatures (mean 20ºC, range 15-26ºC). The natural death of a male held at ambient temperatures occurred at 6 years of age, and at 25ºC natural deaths occurred at 6 years. However, two males, both 12 years of age, one held at 25ºC and the other at ambient temperatures, are still alive. Natural deaths of females occurred at 7 and 12 years of age at 25ºC and 7 years at ambient temperatures. After reaching maturity, females held at 25ºC spawned repetitively. The female that survived to 12 years of age spawned 47 times and produced an estimated 22 × 10⁶ eggs during her lifetime. A fresh mating was not required for the fertilization of each batch of eggs spawned. The two surviving males both showed a change in growth pattern at approximately 8 years of age. This event was correlated with a behavioural change: they attacked and usually killed all moulting females held in the same aquarium. A new method of representing growth data for rock lobsters by fitting empirical stochastic differential equation models to each of a series of growth phases is described.