Family Aplysiidae – Sea Hares

The Sea Hare is an herbivorous sea slug that, according to the Ancient Greeks, looks something like a rabbit. Sea Hares hail from the Order Anaspidea and the Family Aplysiidae. There are nine genera including the genus Aplysia, which contains the Sea Hares most commonly seen in the hobby. While many aquarists have heard horror stories about Sea Hares “inking,” these animals actually make great aquarium specimens if you provide them with the appropriate habitat and meet their dietary needs.

Pound for Pound the Best at Algae Control

All Sea Hares are herbivores, unlike other carnivorous sea slugs (like Chelidonura varians, otherwise known as the Blue Velvet Sea Slug). Sea Hares feed on specific algae or cyanobacteria, and Aplysia species are particularly well-known for their algae-consuming prowess (especially hair algae). The sea hare is very popular and is pound for pound the best at algae control. Sea Hares can be found in all oceans in both temperate and tropical waters. While most are quite small (some are less than an inch), they can grow up to almost 30 inches in length. The Aplysia species offered in the aquarium trade generally grow no longer than one foot.