The Sea Hare, also known as the Spotted Sea Hare, is a somewhat uncommon gastropod mollusc that is most commonly used to rid a tank of nuisance algae. It gets its name from the locations of its rhinophores and oral tentacles that give the appearance of a rabbit’s ears. The sea hare come in a few varieties. One cool variety has blue spots on its otherwise grey/brown body. It is well suited to camouflage itself among the reef rocks. It can grow up to 10” in length and therefore requires a fairly large tank. It is, however, one of the smaller species of sea hare and there is a pygmy type that maxes out at about 3”.
The Sea Hare is found in the Indo-Pacific region at depths of up to 30 feet. In the wild, it is found among the reef rock and feeds almost exclusively on various types of algae. In a home aquarium they absolutely require ample rockwork in order to provide them with enough algae to meet their nutritional needs. Some hobbyists report that they will also eat diatoms and cyanobacteria, but these are not their primary food source. As with all sea hares, it is important to ensure that wavemakers and overflows are properly screened in order to prevent them from being sucked in. While they are less likely to release toxins in the event of death than some of their cousins, it is a good idea to have activated carbon on hand just in case.
The Sea Hare is generally added to a tank for their algae destroying capabilities. They are voracious consumers of many types of algae and can often quickly clear a tank. This large appetite means that there must be ample rockwork to provide enough food for them, as they are unlikely to accept nori or other prepared plant matter.
For a hobbyist looking for an understated algae eating machine that will blend into the rockwork the Sea Hare makes an interesting choice.