California Sea Hare (Aplysia californica) Care Guide
Aplysia californica is a large herbivorous sea hare from the Pacific coast that grazes macroalgae and releases purple ink when disturbed.
Overview
Aplysia californica, the California sea hare, is a large sea slug in the family Aplysiidae, described by Cooper in 1863. It is a herbivore that consumes large volumes of macroalgae and is widely used in neuroscience research because of its simple nervous system of roughly 20,000 large, identifiable neurons.
Taxonomy
- Family: Aplysiidae
- Genus: Aplysia
- Scientific name: Aplysia californica
- Authority: Cooper, 1863
Habitat
The species is found along the coast of California and northwestern Mexico, including the Gulf of California. It inhabits the photic zone, typically the intertidal and shallow subtidal, usually no deeper than about 18 to 20 m.
Description
It can reach up to 75 cm when fully extended and weigh up to 7 kg, though most adults are smaller. Body colour reflects the algae it eats, ranging from reddish and pinkish to brownish. When disturbed it can release reddish-purple ink and a milky white opaline, and it stores algal toxins to deter predators.
Tank requirements
- Minimum tank volume: 200 L
- Temperature: 18-22 °C (64-72 °F)
- pH: 8.0-8.4
- Specific gravity: 1.024-1.026
- Lifespan: about 1 year
Diet
The California sea hare is herbivorous and grazes continuously on macroalgae, with red algae such as Laurencia pacifica, Plocamium pacificum and Ceramium eatonianum among its primary foods. A steady supply of macroalgae is essential to keep it fed.
Compatibility
It is peaceful but best housed in a cool-water tank with calm, non-aggressive fish; predatory or aggressive species should be avoided. Because it grazes macroalgae heavily it is not suited to refugium plants, and the ink response can disrupt water quality in a confined system.
Breeding
The species is a simultaneous hermaphrodite that can form mating chains and lay vast egg strings; one specimen laid roughly 500 million eggs over five months. Adults often die soon after egg-laying, and the generation time is around 19 weeks.