Palio nothus
Britain, Ireland, southern Sweden and coasts up to Arctic Circle on both sides of North Atlantic, but some off-shore records may be P. dubia ( GBIF map). Mediterranean records uncertain because of confusion/combining of P. dubia with P.nothus, but correctly identified 2011 from Croatia [9]. Scattered finds around Britain and Ireland, but probably under recorded because of its camouflage. (UK interactive distribution map.NBN.)
On lower shore, and sometimes sublittorally to 30m, feeding on Bowerbankia spp. (Natuurlijkmooi) Difficult to detect on shore; best sought by examination under magnification of sessile polyzoans in water. Simultaneous hermaphrodite. Spawn mass a laterally compressed cylinder (Seaslugforum) deposited April - September in a loose angulated coil, whitish or tinted rose.
Palio dubia (EML)
- Small isolated tubercles, not breaking ground colour into a network.
- 12 or 13 closely packed lamellae on short stout rhinophore.
- Sublittoral, rarely if ever intertidal. (Many records confuse/combine P.dubia and P.nothus.)
Alder, J. & Hancock, A. 1845-1855. A monograph of the British nudibranchiate mollusca. London, Ray Society.
Johnston,G. 1838. Miscellanea zoologica. Ann. Mag. nat. Hist. 1: 114-125. Free PDF (page 124) at http://biodiversitylibrary.org/bibliography/4227#/summary
Thompson, T.E. & Brown, G.H. 1984. Biology of opisthobranch molluscs 2. London, Ray Society.
Current taxonomy: World Register of Marine Species (WoRMS)
Irish distribution maps and prey organisms:
Picton, B.E. & Morrow, C.C., 2010. Encyclopedia of Marine Life of Britain and Ireland (EML).