Janolus

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Janolus

Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Order:	Opisthobranchia
Suborder:	Nudibranchia
Family:	Janolidae
Genus:	Janolus Bergh, 1884

Species

See text

Janolus is a genus of small to large sea slugs, or more accurately nudibranchs, marine opisthobranch gastropod mollusks, in the family Janolidae.

The name Janolus is derived from the two-headed god Janus, in ancient Greek mythology.

Although these nudibranchs superfically resemble aolid nudibranchs, this genus is in fact in the suborder Arminina.

1 Distribution
2 Habitat
3 Description
4 Life Habits
5 Predators
6 Species in the genus Janolus
7 References
8 External links

[edit] Distribution

Janolus species are found in many areas world-wide, including Europe and Australia and Japan.

The species Janolus fuscus is found from the Kenai Peninsula, Alaska to central California and also in northern Japan^[1].

[edit] Habitat

This genus of nudibranch is found in shallow and subtidal waters.

[edit] Description

Adult individuals of Janolus species can be between 2.5 cm to 8 cm long, depending on the species. They are semi-translucent and the body is covered in short cerata.

The color of the cerata varies according to the species: in Janolus fuscus the cerata are orange and white tipped, whereas in Janolus barbarensis they are orange and blue tipped.

[edit] Life Habits

Janolus species feed on Bryozoa, moss animals.

[edit] Predators

In California, Navanax is a known predator of Janolus. Navanax tracks the slime of Janolus by using chemoreceptors. When Janolus is about to be caught, it rolls into a ball, leaving its cerata exposed.