Fry Experiment

[Angry_Platy]

I have guppy fry...LOTS of guppy fry....unknown to me I was doing an experiment. I had 10 I kept in the breeding trap and the rest I let swim free with the 2 mother guppies. They looked the same size.....till I released the ones from the breeding trap. They are tiny in comparison to the other babies. Like nearly 1/2 their size. I had been feeding the same..in fact, the ones in the trap probably got more food (though they didn't hasve the added advantage of scouring the gravel for food)....

Even more interesting is that 1/2 of the babies in the main tank were born 2 days after the ones in the breeding trap and are still LARGER.....

 

[Talisman]

The ones in the full tank are in a larger space, the ones in the breeding net are enclosed in a much smaller space.

Are they not just growing to match their enviroment?

 

[vidiots]

I have always heard that fish tend to grow at a rate relative to the size of their enviornment with all other things being equal. I dunno if that is just a rumor, or if it has any basis in fact, because I've never actually tried. But now that you mention it, it does seem that the platy fry in my 55gal tank are growing faster than those in my 10gal tank. The problem is that I haven't been keeping track of when which fry were born or even seperating the different batches so I'm not entirely sure which are older. It would be interesting to do a controled experiment to find out exactly what the effect of the size of the tank is.