did stress kill my molly?
I had this swordtail molly for about 8 months now and i’ve never seen anything wrong with her or anything till this morning. Shes very territorial so whenever I add a new fish I try to change the landscaping around. About two days ago, I bought a dalmatian molly and a black lyretail molly. I put them in a hospital tank to watch them for a few hours and noticed the two (who are from seperate tanks) liked eachother a lot and would stick next to eachother no matter what. After concluding they were good to go, I did a small water change on my 29 gallon and changed the landscape around and put my older swordtail in there with the two together with the light off. I noticed the two I recently added like eachother a lot and never really went near my bigger molly, as she would typically stay away from them too on the opposite side of the tank. I never saw anything too aggressive wise with their behavior. I wake up this morning after feeding them the night prior with everyone fine, to FIND her stiff and dead with her mouth open on the bottom of my tank, the other two fish perfectly fine.