The Thecacera Nudibranchs – often also called Pikachu (named after the similar looking Pokemon) – are without doubt one of the more attractive and spectacular groups of nudibranchs. Plus they are not so common. This makes it always nice to see them under water. And over the last week i have already seen several of them here in Lembeh Strait. Mainly on black sand dive spots on the mainland side. The one in the Photo for example was taken at Tandu Rusa – a black sand muck dive in front of a fishing village. It was about 2-3 cm in size, which is already quite big for a Picachu.