Aggression between scorpaenidae

Synanceia · March 22, 2005

Has anybody experienced aggression between conspecifics of these species kept in the same tank: (1) Rhinopias frondosa/weedy scorpionfish, (2) Pteroidichthys amboinensis/ambon scorpionfish, (3) Taenianotus triacanthus/leafy scorpionfish? I have seen P. amboinensis lock mouths and flare their fins, and T. triacanthus flaring fins/opercula and beating their bodies towards members of the same species. But they are okay towards scorpionfish of different species.

I bought 2 P. amboinensis (1 brown and 1 orangy brown) which came in the same shipment and placed them in the same tank. They seem to be okay towards each other for a week. Then I introduced a third P.a. and immediately it fought with the brown one. I separated the two and placed the newcomer in another tank. 3 days later both died. The surviving orangy brown one now has a hole in its lower jaw (with signs of bleeding), which I suspect was bitten by the brown P.a. before the later died. I hesitate to place the survivor in a treatment tank with antibiotics cos I am afraid the stress of catching it and placing it in a new environment will tip it over the edge. It is still interested in and eating live shrimp. However, my feeling is that it is in a 50/50 life and death situation.

As for T. triacanthus, I have already 3 experiences of keeping 2 conspecifics in the same tank and both dying together. Everytime there would be body bending and flaring of fins and opercula, but since there was no actual biting, I had always thought it was only a show of force. But on every occasion, even though they were eating well and showing no signs of ill health, sudden death always prevailed. Right now, I am keeping 2 of these species in separate tanks, and they seem to be doing well.

I also has a R. frondosa for about 2 weeks, but it is not eating. I have tried live mollies and live shrimp, but still it doesn't seem to be interested. If anybody has any suggestions to get it to eat, it will be much appreciated.

If anybody has any experience with these fish, please do share it with me. For members who want to try keeping these species, remember that a cautious approach should be warranted.