CPDs cannibalizing???

[seangee]

Shrimps are fine at 22. They breed slower, grow slower and live longer.

 

[lilsd]

You have an interesting possibility there. Bororas brigittae, the chili rasbora, has a 20-28 temperature range. What would you get if you went with no heater? What are room temps like in your house?

I had a group of the related Bororas maculatus that actually bred quite a bit in a softwater tank at a room temperature of 21-22. So the CPDs are known to like the cooler side of their range, and the Bororas don't mind. I've never kept shrimp to know though.

There's no guarantee it would solve the fighting. But going for the lower safe range with a number of small fish has dialed down aggression here. The fish often live longer too.

Wow that is interesting, I might just give it a try. Maybe it would help improve the algae/biofilm issue too….. I live in a small apartment and the room they’re in is the room that has the a/c. It does stay on the cooler side, closer to 68 but it probably rarely if ever gets colder than 68F. Although the room temperature does fluctuate more than I imagine the tank does with the heater on. Especially on hot summer days, or in the winter when the furnace is going…. It doesn’t bother me living there but I don’t know if it would bother them.

 

[lilsd]

Update: I unplugged the heater a week ago. The Chili’s lost their color for a couple of days but got it right back after a short adjustment period. Everyone is looking good and nobody seems to mind it being a few degrees cooler. I can’t say it’s done much to curb the chasing/aggression in the CPDs, but there haven’t been any more murders yet.

I did try to get some photos of the main culprit, who is also the biggest. These guys are hard to photograph! It also dawned on me, is it possible that they are all males and that’s why they are being so aggressive with each other….? I used to see different kinds of circling/“dancing” kind of behavior but since losing a couple I don’t see that anymore. I’m thinking maybe the ones I lost were the females hence the increased aggression? I don’t know, just a theory. This is the best photo I could get…

 

[gwand]

That is interesting. My male CPDs will circle each other but don’t get physical.

 

[lilsd]

That is interesting. My male CPDs will circle each other but don’t get physical.

Okay yes so maybe I’m off then, but mine used to do this quite a bit, and would also chase each other around, but not nearly as aggressively as they seem to be doing now. Just wondering if the male to female ratio might be the reason for it.

 

[gwand]

There is too much testosterone in the tank!

 

[seangee]

Okay yes so maybe I’m off then, but mine used to do this quite a bit, and would also chase each other around, but not nearly as aggressively as they seem to be doing now. Just wondering if the male to female ratio might be the reason for it.

Most likely #2 in the hierarchy has decided its time to challenge for the #1 spot.
Sometimes this happens when you re-arrange the tank, new plants, decorations etc - or even just moving them around or trimming the plants