I agree it think it is a cynarina lacrymalis. They come in dark, and pastel. I dont think we will know until I can get a good picture of it. I feed it a piece of shrimp every other nite. When the lights are off it has tenticals that come out. The tenticals stick to the food and bring it to the mouth in the middle. It takes about 20 min for it to get the food inside. I will try to put a picture on tomorrow.