Size variations

[L777]

Has anyone else noticed size or growth rate variation? My only other breeding experiences before CPDs were guppies and bushynose plecos, so I don’t have a great deal of “statistical” experience, and none with egg-layers.

I’ve noticed that for CPD fry hatching out at the same time, there are not many that jump ahead quickly in size, but there are a few stragglers who lag behind in growth by a week or two equivalent. Is it best to cull these out before they catch up and are hard to identify as runts? Do they tend to die off on their own? If they do get routinely culled, does this increase the average tank-bred CPD size over time?

On a similar note, I hand-counted over 75 fry reaching the free-swimming stage over a few weeks, while transferring them to other tanks. The oldest are 7 1/2 weeks old now, and the total is down to 58 survivors. All but one tiny runt seem to be doing very well. I never found any dead fish, and many may have been lost in the first few days to hydra or older sibs, although none of the 75 I counted out were subject to predation by adult fish. Does this seem like a typical survival rate, or should it be closer to 100%?

[aquaholic85]

I guess depends on what you plan on doing with the fry and your breeding hobby…try and seperate the ‘runts’ and put them in a small tank or even a breeder net..let them ‘catch up’ with some undivided attention.

maybe you can breed a even dwarf speices…not that these fish aren’t small enough..but hey if you have the time and supplies to do so then why not.

or if you don’t cull or seperate them then jus let them be…survival of the fittest..if they should survive and thrive with the rest of the group then why worry about their genetics if they live…

[L777]

Have to admit I was leaning toward the natural selection process, for the health of the strain.

Does my loss rate seem high to any who have bred lots of clutches (CPDs or other)?

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