This nudibranch was discovered with a most charming "smile" in the middle of a large, empty stretch of sand, and having never seen this species before, I assumed it had been washed in by accident. To my surprise, many more were seen with varied spot and gill size, and I later learned Gymnodoris ceylonica often descend in mass to feed on the sea hare, Stylocheilus striatus, which can appear in huge aggregations. 30mm
29 October 2018