Photo & copyright by: Guido Del Giudice, South-Africa

Janolus capensis  Bergh, 1907 or Janolus longidentatus  Gosliner, 1981
have a look at taxonomy Thanks for identification to Bill Rudman's Sea Slug Forum

Photo details:
size: unrecorded
depth: unrecorded
date: unrecorded
country: Republic of South Africa
location: Cape Town
divesite: False Bay
thumbnail-selection of
Janolus capensis
  taxonomy of
Janolus capensis