Scientific name Janolus Higher classification Proctonotidae | Family Proctonotidae Rank Genus | |
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Similar Nudibranch, Janolus cristatus, Janolus fuscus, Flabellina, Molluscs | ||
Janolus hyalinus
Janolus is a genus of small to large sea slugs, or more accurately nudibranchs, marine gastropod mollusks, in the family Proctonotidae.
Contents
- Janolus hyalinus
- Janolus cristatus
- Description
- Distribution
- Habitat
- Feeding habits
- Predators
- Species
- References
The name Janolus is derived from the two-headed god Janus, in ancient Roman mythology.
Although these nudibranchs superficially resemble aeolid nudibranchs, this genus is in fact in the suborder Arminina.
Janolus cristatus
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.
Distribution
Janolus species are found in many areas world-wide, including Europe, Australia, Japan and Africa.
The species Janolus fuscus is found from the Kenai Peninsula, Alaska to central California and also in northern Japan.
Habitat
This genus of nudibranch is found in shallow and subtidal waters.
Feeding 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.
Species
Species in the genus Janolus include: