[4] Both genera lack ornamentation such as spines and carinae, but are thought to have reached that state independently, through convergent evolution.

The male will then insert a spermatophore into the female's seminal vesicle, where it may be stored for several years.

[17] The eggs of Homarus species are laid in the autumn, being fertilised externally as they exit, and are carried by the female on her pleopods.

[17] The eggs generally hatch in the spring as a pre-larva, which rapidly develops into the first larval phase.

[17] This is followed by three zoeal phases, the total duration of which can vary from two weeks to two months, depending on the temperature.

[17] At the following moult, the young animal becomes a post-larva, with a gross form resembling the adult lobster.