Author:Â Breyn Banks
Common Names:Â Shag-rug Nudibranch, Shag Nudibranch, Shaggy Mouse Nudibranch, Maned Nudibranch
Scientific Name:Â Aeolidia papillosa
Size Range:Â 7 cm in length.
Identification: The shag-rug nudibranch is a smaller nudibranch that is white to pink and has grey patches along its body. It has a shaggy appearance due to the many cerata along its back but has a clear patch in the middle as seen in the photo.
Habitat:Â The shag-rug nudibranch lives in the intertidal zones down to 671m deep from Alaska to southern California. They can be found in a variety of habitats from rocky shorelines to sandy beaches and eel grass beds.
A shag-rug nudibranch (Aeolidia papillosa) feeding on a plumose anemone (Metridium senile)
Prey: The shag-rug nudibranchs feed on various sea anemones. It has a very interesting defence system that goes with its diet. When they feed on the various anemones they store the preys unfired stinging cells (cnidocytes) in their shaggy cerata for their own defence. They appear unharmed by the stinging cells and in captivity we observed one actively feeding on a plumose anemone (Metridium senile). As the defensive strings of acontia came out of the body wall of the anemone the shag-rug nudibranch was eating them up. They also will change colour based on the colour of food they ate much in the way that a flamingo is the same colour of the shrimp it eats.
Reproduction:Â The shag mouse nudibranchs reproduces similar to other nudibranchs. They are hermaphroditic, containing gonads that produce both eggs and sperm. Â Individuals will transfer sperm and the eggs are laid in a gelatinous spiral.
References
Johnson, P.M & Willows, A.O.D, (1999) Defense in Sea Hares (Gastropoda, Opisthobranchia, Anaspidea): multiple layers of protection from egg to adult. Marine & Freshwater Behaviour & Physiology, 32: 147-180.
Hildering, J. & Miller, G., 2007 (Jul 10) Cadlina luteomarginata? being eaten by a seastar. [Message in] Sea Slug Forum.Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20125
Sept, J. D. (2019). The Beachcomber’s Guide to Seashore Life in the Pacific Northwest. Harbour Publishing Company Limited.
The Reproductive Systems of the Nudibranchia (Gastropoda, Opisthobranchia): Comparative Histology and Ultrastructure of the Nidamental Glands with Aspects of Functional Morphology
Photograph by D. Young