Abstract
Populations of Paranephrops planifrons and P. zealandicus were reared in aquaria and their growth rates monitored. When reared in unheated aquaria (10-21.degree. C) P. planifrons grew to 20 mm orbit-carapace length in 12-18 mo. and P. zealandicus reached the same size in 9-10 mo. This is faster, for both species, than in feral populations. When reared in an aquarium at 18-21.degree. C P. planifrons could be grown to 35 mm orbit-carapace length in 18 mo. Mortality in both species was very high (60-93%).