title: Janolus
text: # Janolus
  
  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 into a ball, leaving its cerata exposed.
  
  ## Species
  
  Species in the genus Janolus include:
  
  * Janolus anulatus Camacho-Garcia & Gosliner, 2006
  * Janolus australis Bergh, 1884
  * Janolus chilensis M.A. Fischer, Cervera & Ortea, 1997
  * Janolus comis Er. Marcus, 1955
  * Janolus eximius Miller & Willan, 1986
  * Janolus faustoi Ortea & Llera, 1988
  * Janolus flavoanulatus Pola & Gosliner, 2019
  * Janolus hyalinus (Alder and Hancock, 1854)
  * Janolus ignis Miller & Willan, 1986
  * Janolus incrustans Pola & Gosliner, 2019
  * Janolus kinoi Edmunds & Carmona, 2017
  * Janolus mirabilis Baba & Abe, 1970
  * Janolus mokohinau Miller & Willan, 1986
  * Janolus mucloc (Er. Marcus, 1958)
  * Janolus rebeccae Schrödl, 1996
  * Janolus savinkini Martynov & Korshunova, 2012
  * Janolus toyamensis Baba & Abe, 1970
  * Janolus tricellariodes Pola & Gosliner, 2019
  
  ### Species brought into synonymy
  
  * Janolus barbarensis (J. G. Cooper, 1863):synonym of Antiopella barbarensis (J. G. Cooper, 1863)
  * Janolus capensis Bergh, 1907:synonym of Antiopella capensis (Bergh, 1907) (original combination)
  * Janolus costacubensis Ortea & Espinosa, 2000:synonym of Janolus comis Er. Marcus, 1955
  * Janolus cristatus (Delle Chiaje, 1841):synonym of Antiopella cristata (Delle Chiaje, 1841)
  * Janolus flagellatus Eliot, 1906:synonym of Janolus hyalinus (Alder & Hancock, 1854) (dubious synonym)
  * Janolus fuscus O'Donoghue, 1924:synonym of Antiopella fusca (O'Donoghue, 1924) (original combination)
  * Janolus longidentatus Gosliner, 1981:synonym of Antiopella longidentata (Gosliner, 1981) (original combination)
  * Janolus nakaza (Gosliner, 1981):synonym of Bonisa nakaza Gosliner, 1981
  * Janolus novozealandicus (Eliot, 1907):synonym of Antiopella novozealandica Eliot, 1907
  * Janolus praeclarus (Bouchet, 1975):synonym of Antiopella praeclara Bouchet, 1975
  