New kid + fish deaths = banging head against wall

[theasherrr]

anyone have experience with an over sized black cap basslet? My LFS said it was one of the largest they’d seen and when I described its behavior they were a bit shocked. So upon adding new fish to tank, it swims toward the fish with its mouth wide open as if it’s screaming at the fish. Doesn’t matter the size, the only thing that makes a difference is if the fish was there before the basslet.
I’ve had three fish die within two weeks: gold headed goby, YW goby and a pearly jaw fish. All found in the same area (near or in the black caps cave). None of them had visible bite marks or parasites visible to the eye. I also have a Dragon goby that is doing completely fine with the basslet. The dragon and YW goby were put in together but the gold headed was prior to those two.

I’ve literally got no idea what to do and my only thinking is remove black cap to see if that’s the issue? Thoughts? Happy to share any info, looking for all the help I can get.

tank is about two months old.

sorry about the dirty glass, I tried to snap a quick pic right after I had to fish out the goby.

 

[KING KONG]

anyone have experience with an over sized black cap basslet? My LFS said it was one of the largest they’d seen and when I described its behavior they were a bit shocked. So upon adding new fish to tank, it swims toward the fish with its mouth wide open as if it’s screaming at the fish. Doesn’t matter the size, the only thing that makes a difference is if the fish was there before the basslet.
I’ve had three fish die within two weeks: gold headed goby, YW goby and a pearly jaw fish. All found in the same area (near or in the black caps cave). None of them had visible bite marks or parasites visible to the eye. I also have a Dragon goby that is doing completely fine with the basslet. The dragon and YW goby were put in together but the gold headed was prior to those two.

I’ve literally got no idea what to do and my only thinking is remove black cap to see if that’s the issue? Thoughts? Happy to share any info, looking for all the help I can get.

tank is about two months old.

sorry about the dirty glass, I tried to snap a quick pic right after I had to fish out the goby.

It can reach to about 11 cm. They r confident fishes. Actually they r not aggressive. They r territorial. Mine chase and pick on other fish, and love to kill shrimp. So whatever will come in it's place, will be brutally chased. They attack similar-looking species, conspecifics, and their kind. Still I doubt that your's had killed that fishes as they r the best tankmates you can keep with it so have u seen it chasing them?

 

[theasherrr]

Yeah I’ve seen it chase them- swim at them with it’s mouth wide open like it’s screaming.

 

[KING KONG]

Yeah I’ve seen it chase them- swim at them with it’s mouth wide open like it’s screaming.

So that's mean it may have killed them. It will chase anything that will come near its hiding place. You can add big peaceful fishes.

 

[Nemo&Friends]

you may want to place your basslet in isolation next time when adding some fish. let him in an acclimation tank, or section the tank with egg crate for a few days, until the new fish are acclimated. Then release the basslet. It might help. I did that with an aggressive damsel. It solved the problem.

 

[Cthulukelele]

I know some basslets can be absolute demons, and they're powerful fish who can do a lot of damage when they go in on other fish.

 

[theasherrr]

I know some basslets can be absolute demons, and they're powerful fish who can do a lot of damage when they go in on other fish.

Yes my basslets is absolutely terror. I’ve been attempting it catch it for the last few weeks and it still hasn’t been susccesful. It killed one of my favorites so now I’m ready for it to go.

Any suggestions on catching?