Juvenile hormone effects on metamorphosis of lobster larvae

Abstract

The insect developmental regulator, juvenile hormone III, or its presumed precursor, farnesol, (10⁻⁷ M and 10 ⁻⁶ M), were added to water in which larval lobsters (Homarus americanus) were allowed to develop. The most reproducible effect observed was a prolonging of the time to metamorphosis (hatching to fourth stage). Only JH III was effective. Morphological parameters such as carapace, antennae, and chelae lengths were also measured after metamorphosis. It was observed that JH III generally decreased carapace length, but increased the lengths of the antennae and chelae. These latter morphological alterations were occasionally also seen with farnesol treatment.