This is a nudibranch named “Anna’s Chromodoris”. There is a term in SCUBA diving called “muck” diving. It means to search through the sand, mud and other detritus at the bottom of a murky body of water looking for beautiful and interesting sea creatures such as this one. I spent a week with Lonestar Scuba doing just that in the Lembeh Strait, Indonesia back in 2016. This was just one of the beautiful and interesting sea creatures we found. Lembeh is famous for its “muck” diving and did not disappoint us.
Anna’s Chromodoris - Lembeh, North Sulawesi, Indonesia - 2016