Firefish goby's

I got a pair of firefish goby's a few months back and one of them disappeared a month or so ago. In my research, I've seen arguements to introduce a new pair with the existing one, introduce a single new one in with the existing one and not to introduce any new ones. With the Angel and the clowns and the gramma already established in the tank as well, what would you all recommend?

 

Unless the firefish are a mated pair, it's likely that they will fight to the death. Not saying that's what happened to your fish but I've had it happen in mine. Have you checked around your tank? They are notorious jumpers after all.

 

I never saw them fighting. And unless the cat got to him out of the tank, don't think he jumped. But both possibilities I guess.
Based on what you say though, even another pair would most likely kill the one that's there now?

 

check, i didnt know mine jumped...i found him like 3 weeks later

 

Unless your tank is really large, a pair of females or males will fight. You might not see it but it's possible that it's happening when you aren't looking. There is a way to sex these gobies but it's not very easy to do so. It has something to do with the dorsal fin but that's about all I know.

 

So, it sounds like you think that it's probably best not to try and get an new partner for the one I've got...

 

Not unless you can be sure that you've got a mated pair or unless you get a larger tank. Getting a larger tank sounds good