Blue Dragon Nudibranch (Pteraeolidia sp.) ムカデミノウミウシ (size 22cm)
Both (Pteraeolidia semperi) and (Pteraeolidia ianthina) look alike with a wide variation of appearance. They can white or blue with purple bands on the oral tentacles. Some sources have Pteraeolidia semperi with two distinct cephalic tentacles. They both have the same common names in Japanese and in English. They have zooxanthellae and nematocysts that they get from their diet. I am sure there are a lot of misidentifications. Enoshima 2018
This is a white version of the Blue Dragon. Amami 2022
These Blue Dragon Nudibranchs have just a little blue. Amami 2024