among 8 Mollies, 3 Angelfish and 2 Swordtails...The Crayfish finished off 7 Mollies and a swordtail within 2 nights, till I realised it was the culprit, I actually saw it eating one of my beautiful White Mollies...Anyways, I immediately transfered him to my brothers tank, where it lived happily for a year after that...