I lost a male Molly this past weekend. I checked the water and all is well. It looks like one of my females is getting weak now. I picked up 3 ghost shrimp and a female golden gourami on Friday only to have to separate her into a fry net/cage due to injury. It appears my formerly sweet and social Opaline Gourami has turned into a harassing bully. He's bitten off half of her tail and lower fin. He's chasing the mollies and platys and guarding his food like a hungry dog. I've been feeding them more just to make sure they get their share and saw that the one female Molly is doing better. He's being such a turd that all the other fish are scared of him.