Facelina bostoniensis
<p><em>Facelina bostoniensis</em> (Couthouy, 1838)</p>
Facelina bostoniensis
New England, USA, and Southern Norway to Spain and western Mediterranean. (GBIF map) Widespread and common around Britain and Ireland. (UK interactive distribution map N.B.N.)
- Usually iridescence on cerata and, sometimes, on head and body, occasionally not.
- Cerata usually neatly swept back, each group only slightly overlaps the next behind.
- Rhinophore lamellae alternate complete/incomplete disk.
- Propodial extensions shorter and stouter than on F. bostoniensis.
- White pigment splashes down front of cerata.
Facelina dubia (EML) Very similar to F. bostoniensis
- Smooth rhinophores lack lamellae.
- White pigment flecks on head and oral tentacles.
- In British & Irish waters, so far only recorded in Lough Hyne in SW Ireland.
- Cerata long, linear, rather untidy and lack iridescence [3]. (Occasionally, a small amount of iridescence on the head or oral tentacles; very rarely all over cerata).
- No white pigment splashes down cerata, apart from small patch near top [2]. (Sometimes a minute white spot or two on front of cerata.)
- Rhinophore lamellae all complete disks.
- Slender sickle-shape propodial tentacles [2].
Alder, J. & Hancock, A. 1845-1855. A monograph of the British nudibranchiate mollusca. London, Ray Society. Anderson, J. Scottish Nudibranchs (ScotNud).
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).
Body (excluding appendages)