Aquaponics - Selective yabby breeding

I still have my yabby brood in a small aquarium sitting on my desk. As I type I'm watching them going all crazy for some fish food flakes.

Some are much, much bigger than others. Originally the difference was only 10% or so, but now some are three times the size or more than the smallest.

I get the feeling that people would always selectively breed from the fastest growing yabbies so that they might get a more productive farm over a few generations, but studying their behaviour up close like I am, I'm starting to wonder if that might be a bad idea.

The big ones are always the aggressive ones.

No doubt they got that way because they are getting more than their fair share of the food supply, and perhaps by eating one or two of their brothers and sisters along the way.

Perhaps that's not a good way to run a farm. Where some of your cows are eating the others, or at least stealing all their food.

One of my batch of yabbies seems to not be part of any of this. It's on the large side of medium in size, and seems to spend most of it's time grazing algae from the surface of a sheet of gutter guard (plastic mesh to keep leaves out of your house gutters). Mostly it's left alone, and more often than not leaves others alone when they occasionally venture onto it's bit of turf.

I think this kind of beast might be a better candidate to breed from.

Not quite as big, but a lot more sociable and a bit less cannibalism.

And who knows, perhaps without the aggressive ones, this type would be just as big.

I'm going to try to find out.



120 Things in 20 years went to a lousy seafood restaurant, but now wants to eat more crustaceans.