Janolus is a genus of small to large sea slugs, or more accurately nudibranchs, marine gastropod mollusks, in the family Janolidae. The name Janolus is derived from the two-headed god Janus, in ancient Roman mythology. 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. Distribution Janolus species are found in many areas world-wide, including Europe, Australia, Japan and Africa. Ecology 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...