Dendronotus lacteus

Dendronotus lacteus is a species of sea slug, a dendronotid nudibranch, a shell-less marine gastropod mollusc in the family Dendronotidae.

Distribution
This species was described from a specimen collected at the entrance to Strangford Lough, Northern Ireland, Irish Sea. It was long considered to be a synonym of Dendronotus frondosus but separated by Thollesson in 2000 using the technique of allozyme electrophoresis. This was confirmed with DNA sequencing in 2015. The species is known from the Irish Sea north to Spitsbergen, Franz Josef Land, and the Barents Sea.