Differences in size of same-aged growing up fry?

[hollyfish2000]

Just curiousa about this. I've had seven baby albino long-finned BN plecos for about six months now. All arrived nearly the same size. Now, several are quite large and some appear not to have grown at all. They are in two different tanks and all are still alive and apparently thriving. The largest are maybe twice or almost three times as large as the smallest. Can I chalk that up to gender? Are the bigger ones males?

I'm also seeing this in my rainbow cichlids. I've got two babies of the same age and one is twice as big as the other. Just curious . . .

 

[Tony]

Hey Holly,

It may be a male/female thing, but more likely, it' just genetic differences causing different growth rates. I see it a lot in my fry and generally cull the smallest/skinniest ones. Sometimes they catch up, but more often not.

Same goes for puppies (the runt part, not the culling part).... In every litter, you get a little guy.

 

[iamzrad]

I have a Ngara peacock that is probably 1.75-2yrs old and is still under 2.5" lol.

But yes, as Tony pointed out it could be a male/female thing. But also, depends how that certain fish eats and how much it eats plays a big factor.

 

[dogofwar]

With some fish it's more pronounces than others. I think early on it has a lot to do with access to food.

 

[hollyfish2000]

Interesting. Well, I'll keep an eye on it and see how it turns out when they get big enough to sex. As for the ABNs, when I got the seven (I actually only ordered six), I only needed two, including a female. I planned to sell off the rest, but they are so darn cute that so far, I'm unwilling to part with any of them. When they get big (and obviously boy), though, some will have to go. It's also interesting in that some are pink and some are variations of peach . . .

 

[mrkillie]

Some ABNs are also crosses of different species, and the difference in the genetic code could well account for the diiferent sizes and colors.

 

[gravel_digger]

Mother Nature only the strong shall and all other perish to ensure the survival of the species....