I have six Cardinals in a community tank with other peaceful fish.
Yesterday I introduced two more and this morning both of them were dead. They were fine last night, active and eating, but were floating in the tank this morning, both with most of their tails bitten off. The two new arrivals were slightly smaller, hence how I know it is these which have succumbed.
The only other inhabitants of the tank are female Gourami's x 2, Corry's, Rummy Noses, Oto's and Yamato Shrimps. My tank water is fine; no nitrates, nitrites or ammonia and all the other fish are good. Water temp is 28C, PH 7.2.
I suspect that these losses may be stress related and the tails have been nibbled post-mortem. Am I correct?
Best regards,
Eric