Someone here posted a thread a while back showing wild differences in fry size from the same spawn after a few months. They wondered why some were so tiny and some so large.

I'm having the same phenomenon with my Lab. Hongi fry, and I have a theory on the "why" in this case.

In the 6G Eclipse self-contained system I use as my isolation/fry tank, the in-hood filter drips a steady stream of water into one side of the tank, oxygenating it as it returns water from the filter. Food dropped on the calm side stays at the surface much longer. Food dropped on the "rapids" side gets splashed down into the water column (OK, that's exaggerating on a 6G...).

Initially all my fry don't know to go to the surface for food and they wait for it to come down to them. After a few days, they gradually learn how to cut into the lunch line and go to the surface. Of my 14 Hongi fry, two in particular staked out territories where they stayed behind after everyone else went up top, and enough food came down to them that they did OK, though they were a little smaller than their brothers and sisters.

Once they got to about 1/4"-1/2" and were moved to the 12G Eclipse as the next grow-out tank, the Hongi started feeding voraciously from the surface the moment I dropped in food, in typical cichlid fashion. But those two never changed their strategy of waiting for the food to come to them, and staked out similar positions in the larger tank.

As they near 3 months old, the largest fry are over 1" long, but the "wait for it" guys are still under 1/2", less than 25% the body mass of their brethren.

So there you have it: one theory on the size disparity issue.

Don

kimmy DON, DO YOU HAVE ANY PICS OF YOUR YELLOW LABS,(FRY & PARENTS).I'D LIKE A COUPLE.I DON'T KNOW IF YOU ARE LETTING SOME GO...

They're in my work tank, so I don't, I'm afraid.

Because I was dumb and left them in with the mother too long, I had only one survivor from my first and only spawn with them.

When I have more I'd love to swap.

That's as good of reasoning as any, Don. I always have vast size differences in all my fry groups growing out. It's a little frustrating...I like to take larger groups to the LFS, and when I wait on the smaller ones to get big enough, the larger ones wind up getting territorial and force me to move them to a larger tank.

I've gotten to the point where I take the larger ones and move them in with the adults, leaving the smaller ones in a grow out tank for a longer period of time. This allows the little ones to be more competitive for food, and forces the larger ones to slow down on their growth a bit when competing with the adults.

Of course, it's a pain to tear down the main tanks to remove them when it's time to go to the LFS!

Kim

I did post these pictures a while back about the differences in fry growth. They were all from the same batch and there was a huge size disparity.






And I have noticed the same thing that you have about the smaller ones not coming to the surface or being as aggressive in their eating habits. I do all I can to get the food down to them, but by that time the others have gobbled up everything on top and are competing down lower. dumb dumb

I used to move them to other tanks or put them in breeder boxes to insure they got their fair share, but now I just let it go as survival of the fittest.

I agree with you, Aura -- I drop food for them on the "rapids" side at the same time as I drop it on the calm side, but after that it's up to them.

Kim, this batch of Acei are the first ones big enough for me to consider taking as a group. I can alreadys ee that at best I'll be able to take them in two waves.

My Lab. Hongi fry are mostly going to build my community, though extra males will get swapped. I only wish that Canada, Kentucky etc. were an hour away so I could trade with people from here!