I have what I believe to be a Blue Crayfish (Label at the pet shop said "Blue Lobster") and it has started acting strange. I got it yesterday and it was very active, walking around the tanks edge etc. but today it seems like it is dying. Earlier it was laying on it's back and I've given it lettuce/fish flakes because I researched and saw that it is okay to feed them that. She hasn't been eating anything from what I can tell and I have put her in a tank by herself until she becomes active again. Due to her seeming ill, I have her in a smaller tank (roughly 5 gallons but she's a baby I think). What could be the issue? It is also missing one leg and I was thinking one of my other fish might have got it but then I noticed the leg in the new tank I have her in. I moved it to a smaller tank so it can be by itself and left alone. What can I do to rehabilitate it? Here is a picture of it: Any help would be greatly appreciated because even though I JUST got it I still like it a lot and want to see it get better asap.