White-and-Orange-Tipped Nudibranch

Janolus fuscus

Summary 5

Janolus fuscus is a species of sea slug, or more accurately a nudibranch, a marine opisthobranch gastropod mollusk, in the family Proctonotidae.

Description 6

The bodies of nudibranchs in this species are semi-translucent. The body is covered in short cerata. In Janolus fuscus the cerata are orange and white tipped.

Distribution 6

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

Habitat 6

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

Life habits 6

Janolus species feed on Bryozoa.

Predators 6

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. If there is a water current, as if often the case, the sea slug may then be passively rolled away from the predator.

Sources and Credits

  1. (c) Robin Agarwal, some rights reserved (CC BY-NC), https://www.inaturalist.org/photos/8993018
  2. (c) Minette Layne, some rights reserved (CC BY-SA), http://www.flickr.com/photos/minette_layne/3662090360/
  3. (c) matt knoth, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/mattknoth/3682179067/
  4. (c) Phil Garner, all rights reserved, https://www.inaturalist.org/photos/9684893
  5. Adapted by Robin Agarwal from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Janolus_fuscus
  6. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Janolus_fuscus

More Info

iNat Map

Color orange, white