Janolus

Taxobox
name = "Janolus"
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
ordo = Opisthobranchia
subordo = Nudibranchia
familia = Janolidae
genus = "Janolus"
genus_authority = Bergh, 1884
subdivision_ranks = Species
subdivision = 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.

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 [cite web | url = http://www.seaslugforum.net/factsheet.cfm?base=janofusc | publisher = Sea Slug Forum| title = "Janolus fuscus" | accessdate = 24 Dec | accessyear = 2006] .

Habitat

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

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.

Life Habits

"Janolus" species feed on Bryozoa, moss animals.

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.

pecies in the genus "Janolus"

* "Janolus barbarensis" (J. G. Cooper, 1863) - cockscomb nudibranch
* "Janolus comis" Er. Marcus, 1955
* "Janolus cristatus" (delle Chiaje, 1841)
* "Janolus fuscus" O'Donohue, 1924
* "Janolus hyalinus" (Alder and Hancock, 1854)
* "Janolus mucloc" (Er. Marcus, 1958)
* "Janolus novozealandicus" (Eliot, 1907)

References

*
* Powell A. W. B., "New Zealand Mollusca", William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1

External links

* [http://www.nwmarinelife.com/htmlswimmers/j_fuscus.html Janolus Fuscus] A picture of Janolus.
* [http://www.lcsc.edu/biology/REFS/latin.html A Glossary of Latin Names]