Dace Agression?

[KyleighG524]

Recently I've moved back into my dorm with my 10 gal tank of dace and darters. 3 rainbow darters, 2 fantail, and 4 blacknose dace and 2 s. redbelly. Before they came home with me everyone got along well, and my dad said everything was fine when they were with him. They did go through a temperature change, from ~70° to around 50~60° water, then back up to a warmer temperature, and I've recently added rock hides in with their plants. It's really just one dace, whom I think is female, that is being aggressive. Usually they would chase each other around, but now she's guarding the rock and chasing darters and the redbellies away. Is she gravid and getting ready to lay? Or is she just being a diva?

I saw a thread with this same 'issue', but the guy said his problem resolved because his fish died.

 

[divemaster99]

If it is a female then I doubt it'd be the one guarding the spawning grounds. Any pictures? That might help determine the sex.

In my experience with Rhinichthys dace, however, they're just in general a boisterous species of Cyprinid and I never had luck keeping mine with darters. That may have just been my experience, though.

 

[KyleighG524]

If it is a female then I doubt it'd be the one guarding the spawning grounds. Any pictures? That might help determine the sex.

In my experience with Rhinichthys dace, however, they're just in general a boisterous species of Cyprinid and I never had luck keeping mine with darters. That may have just been my experience, though.

There's the cove and the offending fish. He's got a reddish stripe where the black usually lies, so I'm thinking it is a male. Out of all my blacknose he's the biggest though, so I thought it may have been a gracid female. Just bought another hide, so hopefully it eases some tensions.

 

[predatorkeeper87]

my largest blacknose dace out of the group of 7 or 8 does this every year. turns a pinkish red color on his sides and chases everything in the tank away from a rock formation I made for the darters.

 

[Gill Blue]

temperature fluctuations like the one you mentioned can often be a trigger for spawning.