Aeolidia papillosa

The Sea Mouse

Phylum Mollusca
Class Gastropoda
Subclass Opisthobranchia
Order Nudibranchia
Suborder Aeolidiida
Family Aeolidiidae
Genus Aeolidia
Species papillosa

Description: 10 cm long, 4 cm wide; cerata are grayish-brown, sometimes with white tips; thick, stubby body with a whitish-gray or brownish color; has a translucent appearance; a triangular area, without cerata, runs from the rhinophores down the middle of the back.

Habitat: Found at or below the low tide area on rocks and in mudflats. Also common on pilings and boat docks.

Natural History: It feeds mainly upon sea anemones, especially Metridium, and can grow quite large for local nudibranchs. It is an active carnivore and swims well. Their thick, shaggy, and crowded look gives this animal its common name. This nudibranch obtains nematocysts, or stinging cells, from eating anemones. These cells are stored in the tips of their cerata and used for defense.