Please help with aggressive neon goby's

[abirozy]

Hello

I have a 28 gallon nano led with about 30 lbs of live rock and 30 lbs of live sand. I have 2 clowns, a gumdrop goby, and 2 neon goby's. The 2 neons came together from the mail. The blue neon is slightly larger than the yellow neon and recently has developed a little Ich problem.

PROBLEM:

Today I found the blue neon chasing the yellow around the tank. He would dart at the yellow neon and they would zoom around the tank. When I look closely, the yellow does not seem beat up but she does have some new black hatches on her back that look almost like she rubbed up against something dark. The blue neon in addition to a minor case of Ich, also look likes his fins have been nibbled a bit.

The neon goby's have ALWAYS gotten along before. They would often rest on the same rock and I actually began to think they were a mated a pair. UNTILL TODAY.

QUESTION:

1) What happened to make the blue neon go after the yellow neon?

2) Is this some weird mating thing?

3) Is it possible the blue neon being sick made him aggressive?

4) Or can two fish that have always gotten along suddenly become aggressive?

5) Finally, any suggestions on how to deal with the issue? I have not been able to trap the blue neon.

Thanks

Adam

 

[CastAway]

Tagging along...

 

[mnat]

If you have two of the same sex you will have some aggression

 

[abirozy]

I was thinking of that, but wouldn't they have had the aggression all along? Mine were getting along so well I figured they were opposite sexes.

 

[Naiad]

They will get along as juveniles but if they are the same sex as soon as they reach maturity they will fight. I had to remove one from a 120 gal because I had two males and they about killed each other one day....