@Ebirah766 Don't be too happy about it. I enjoy seeing such a variety of sea slugs in captivity, but about 99% will starve to death since barely any aquariums can provide enough food. Each species has a very specific diet of sponges and relatives. The Japanese aquariums will just catch new ones when they die, the ones exported into the aquarium trade worldwide also starve because of lack of food. Only a few facilities really try to keep them successfully.
Unfortunately nudibranch care is ultimately just throwing stuff at a wall until it sticks. The vast majority of species will feed on only one or two species of sponge, and it is often unknown which species they do feed on. So keeping nudibranchs is often a case of just throwing live rock covered in sponges at the nudibranch, and pray that it has the right sponge species on it. A lot of nudibranchs will die before you luck out with the right sponge species.
Monterey and a few other aquariums have kept Monterey sea lemons and several other species successfully, in the tank they are housed in there are puff ball sponges (Tethya aurantia?) which seem to be eaten regularly. Egg cases also are produced in the tanks.
