California sea hare

Aplysia californica · The California sea hare is a large sea slug found along the coast of California and northwestern Mexico, including the Gulf of California.

California sea hare
Photo: Greg Schechter from San Francisco, USA, CC BY 2.0
California sea hare
Photo: Ed Bierman from CA, usa, CC BY 2.0
California sea hare
Photo: Claire Fackler, CINMS, NOAA., Public domain

Taxonomy

KingdomAnimalia
PhylumMollusca
ClassGastropoda
OrderAplysiida
FamilyAplysiidae
GenusAplysia
SpeciesAplysia californica

Where it lives

Kelp beds and tide pools from Oregon south to Baja.

Fun facts

  • A California sea hare can stretch up to 75 cm long when crawling and weigh as much as 7 kg.
  • Sea hares are both male and female at once, and they can link up in mating chains of up to 20 animals.
  • One sea hare was recorded laying about 500 million eggs at 27 separate times in less than five months.
  • By eating algae, sea hares take in toxins and store them in their bodies to repel predators.

Play it

The California sea hare was the creature in a regional daily on November 2, 2026. Can you identify tomorrow's from its photos? Every day brings a new creature to place from kingdom to genus, map and name.

Play today's creature or replay a past daily

Facts and taxonomy adapted from Wikipedia (CC BY-SA 4.0).