Dendrodoris denisoni (Angas, 1864). Yet another new find for me.. this one was busy munching though and wouldn't move to give me a better shot 😑
Nudibranchs are amongst the most ephemeral of marine creatures. Seldom will one be able to visit a location with the intention of finding a particular species and locate it successfully. Nudibranchs tend to be rare in time and space. For example, the aeolid Babakina caprinsulensis was described, on the basis of a single specimen (collected in 1965) , from Leigh, New Zealand and no further specimen has been found subsequently despite thorough searching.
Edit by wifu @manta_maycee