US Native Fish Care Sheets

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SunnieKeeper, it sound like you might have two males.....Rock bass can get big (12-18 inches max) and like Green Sunfish are tough and territorial; you did really well by putting in structure, but what would also help is a tank bigger than 90g, dithers that are about the same size and tough and fast(creek chubs, Golden Shiners, fallfish, Northern Studfish, etc), and a bigger females to male ratio (to spread the aggression around). Temps (make sure its not too hot) and the right amount of feeding will also help decrease aggression.
 
Yeah .. they're both males. Didn't know it at the time unfortunately. They were only about 2.5-3" long when I put them a 75 gal with my Bluegills which were about 4"-6". It didn't matter, mean one still ended up terrorizing the tank.

I think I should have put them both in the new tank as the same time. That might have helped .. or not ??? Putting the less aggressive one in first only made him want to fight harder for territory he'd already claimed, so that kind of backfired on me.

Tank is kept in semi-unheated basement so winter temps get to about 58 degrees. In summer it never gets above 75. If it gets above 75 I put the window air on since I don't like it hotter than that either.

They are currently still small enough for a 75g with a few dither fish but not a school of them. Finding them big enough not to be food is another story though. I'm going to give them another little bit to see if they calm down & can get along. If not, I'll probably end up putting them in separate tanks again. At least until I can find a bigger tank.
 
I love Rock Bass, we have a smaller subspecies here called "Ozark Bass" that max out at about 10 inches; but even they are aggressive little buggers for their size. I think your main problem is there are too many males and not enough females in that size of a tank, also Im not sure what kind of structure you have....if they can still see each other , without dithers and in a nest range vicinity, they will still battle. Driftwood, tough plants, some type of clay pots are all good structure, and the dithers I posted above have worked with Green sunfish, so they should be ok with Rock Bass, ps if your caves can support it Stonecats might be a good dither also, but other Centrarchids will be seen as rivals unless you have a larger tank.....IMHO I believe the minimum size tank for Bluegill, and other large Lepomis, Rockbass, Sacramento Perch,Pomoxis and the Smaller Micropterus should be a 125g; this is after my experience with trying to keep Green Sunfish in a 38g bowfront. A 75-90 is the perfect size I believe for Shadow bass, Longear, Spotted, Mud , Dollar sunfish and Fliers.
 
SunnieKeeper, it sound like you might have two males.....Rock bass can get big (12-18 inches max) and like Green Sunfish are tough and territorial; you did really well by putting in structure, but what would also help is a tank bigger than 90g, dithers that are about the same size and tough and fast(creek chubs, Golden Shiners, fallfish, Northern Studfish, etc), and a bigger females to male ratio (to spread the aggression around). Temps (make sure its not too hot) and the right amount of feeding will also help decrease aggression.

Not questioning you since I know it isn't rare but if someone on here has a rock bass bigger than 16" please post a picture of such a monster.
 
Right now they seem to be getting along a little bit better. At least Lil' Red (less aggressive one) is not getting beat up and seems to be less stressed. Basically how it's working right now is Lil' Red finds a spot where-ever Skitzy (aggressive one) isn't ... which is usually other end of tank but not always. Funny, just now he's hanging out under an arching branch of driftwood which hangs over the cave Skitzy sits in during the day. Skitzy went to the fake log which is normally where Lil Red hangs out. Therein lies the problem .. Skitzy thinks the whole tank & all caves are his territory.

The good thing is at night Lil Red likes to hang out in the middle of the water column whereas Skitzy rarely ventures up that high .. he's a bottom hugger. I'm still slightly modifying some stuff such as moving tall plants around to block views, etc. Most of the tall plants are in the middle of the tank. On top of one cave I put a piece of driftwood log to make like a wall then all around it is tall plants. Lil' Red likes (liked?) to sit there at night surrounded by the driftwood & plants. It was a safe spot but Skitzy noticed it the other night & chased Lil Red out so not as safe as it used to be.

Sometimes I think Skitzy gets jealous when I'm paying attention to Lil Red & comes to chase him. LOL More logical reason is because he knows where to find him cause I'm pointing him out. So sometimes I cause the problem. :uhoh:

I'll try to post a pic of what my tank looks like soon. Things have been a bit hectic.

Edit: From everything I've read Rock Bass range from 6"-12" at least in my area.
 
Nice shots of the rock bass.
 
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