View source for Janolus

{{Short description|Genus of gastropods}}
{{Automatic_taxobox
| image = Janolus.jpg
| image_caption =
| taxon = Janolus
| authority = Bergh, 1884<ref>Bergh, L.S.R., 1884. Report on the Nudibranchiata dredged by H.M.S. Challenger during the years 1873-1876. Report of the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873-76, under the command of Captain George S. Nares, R.N., F.R.S. and Captain Frank Tourle Thomson, R.N. prepared under the superintendence of the late Sir C. Wyville Thomson, Knt., F.R.S., &c. Regius Professor of Natural History in the University of Edinburgh Director of the Civilian Scientific Staff on board, and now of John Murray one of the naturalists of the expedition, Zoology 10(26):1-154, pls. 1-14.</ref>
| type_species = ''[[Janolus australis]]'' <small>Bergh, 1884</small>
| subdivision_ranks = Species
| subdivision = See text
| synonyms_ref = <ref name="WoRMS" />
| synonyms =
* ''Janus'' <small>Vérany, 1844</small> (invalid: junior homonym of ''Janus'' S<small>tephens, 1829</small> [Hymenoptera])
}}
'''''Janolus''''' is a [[genus]] of small to large [[sea slug]]s, or more accurately [[nudibranch]]s, [[marine (ocean)|marine]] [[gastropod]] [[mollusk]]s, in the [[family (biology)|family]] [[Janolidae]].<ref name="WoRMS" /> The name ''Janolus'' is derived from the two-headed god [[Janus (mythology)|Janus]], in ancient Roman mythology.
==Description==
Adult individuals of ''Janolus'' species can be between 2.5&nbsp;cm to 8&nbsp;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 inermis|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:<ref name="WoRMS">MolluscaBase (2019). MolluscaBase. [http://molluscabase.org/aphia.php?p=taxdetails&id=138379 ''Janolus'' Bergh, 1884.] Accessed on 2020-10-20.</ref>
* ''[[Janolus anulatus]]'' <small>Camacho-Garcia & Gosliner, 2006</small>
* ''[[Janolus australis]]'' <small>Bergh, 1884</small>
* ''[[Janolus chilensis]]'' <small>M.A. Fischer, Cervera & Ortea, 1997</small>
* ''[[Janolus comis]]'' <small>Er. Marcus, 1955</small>
* ''[[Janolus eximius]]'' <small>Miller & Willan, 1986</small>
* ''[[Janolus faustoi]]'' <small>Ortea & Llera, 1988</small>
* ''[[Janolus flavoanulatus]]'' <small>Pola & Gosliner, 2019</small>
* ''[[Janolus hyalinus]]'' <small>(Alder and Hancock, 1854)</small>
* ''[[Janolus ignis]]'' <small>Miller & Willan, 1986</small>
* ''[[Janolus incrustans]]'' <small>Pola & Gosliner, 2019</small>
* ''[[Janolus kinoi]]'' <small>Edmunds & Carmona, 2017</small>
* ''[[Janolus mirabilis]]'' <small>Baba & Abe, 1970</small>
* ''[[Janolus mokohinau]]'' <small>Miller & Willan, 1986</small>
* ''[[Janolus mucloc]]'' <small>(Er. Marcus, 1958)</small>
* ''[[Janolus rebeccae]]'' <small>Schrödl, 1996</small>
* ''[[Janolus savinkini]]'' <small>Martynov & Korshunova, 2012</small>
* ''[[Janolus toyamensis]]'' <small>Baba & Abe, 1970</small>
* ''[[Janolus tricellariodes]]'' <small>Pola & Gosliner, 2019</small>
;Species brought into synonymy:
* ''Janolus barbarensis'' <small>(J. G. Cooper, 1863)</small>:synonym of ''[[Antiopella barbarensis]]'' <small>(J. G. Cooper, 1863)</small>
* ''Janolus capensis'' <small>Bergh, 1907</small>:synonym of ''[[Antiopella capensis]]'' <small>(Bergh, 1907)</small> (original combination)
* ''Janolus costacubensis'' <small>Ortea & Espinosa, 2000</small>:synonym of ''Janolus comis'' <small>Er. Marcus, 1955</small>
* ''Janolus cristatus'' <small>(Delle Chiaje, 1841)</small>:synonym of ''[[Antiopella cristata]]'' <small>(Delle Chiaje, 1841)</small>
* ''Janolus flagellatus'' <small>Eliot, 1906</small>:synonym of Janolus hyalinus <small>(Alder & Hancock, 1854)</small> (dubious synonym)
* ''Janolus fuscus'' <small>O'Donoghue, 1924</small>:synonym of ''[[Antiopella fusca]]'' <small>(O'Donoghue, 1924)</small> (original combination)
* ''Janolus longidentatus'' <small>Gosliner, 1981</small>:synonym of ''[[Antiopella longidentata]]'' <small>(Gosliner, 1981)</small> (original combination)
* ''Janolus nakaza'' <small>(Gosliner, 1981)</small>:synonym of ''[[Bonisa nakaza]]'' <small>Gosliner, 1981</small>
* ''Janolus novozealandicus'' <small>(Eliot, 1907)</small>:synonym of ''[[Antiopella novozealandica]]'' <small>Eliot, 1907</small>
* ''Janolus praeclarus'' <small>(Bouchet, 1975)</small>:synonym of ''[[Antiopella praeclara]]'' <small>Bouchet, 1975</small>
==References==
{{Commons category|Janolus}}
{{Reflist}}
{{Taxonbar|from=Q3020001}}
[[Category:Nudibranchia]]