Splendid Sapsucking Slug (Thuridilla splendens) ハナミドリガイ – size 5cm
The splendid Sapsucking Slug is not a nudibranch but a slug. They feed on green algae. They are found in Japan. There are similar looking slugs identified as Thuridilla splendens found elsewhere in the Pacific. they could be a different color variation or a different species. This one matches the color pattern of the original description from Japan. I would have taken a better picture of it, but I was taking a picture of the shell. I didn’t notice the slug until afterwards. Amami 2026