Backyard Aquaponics
A place to discuss aquaponics

Right you are C1, but at the end of the day for the average APer I don't think they are worth the hassle and disappointment

Marron seem happy enough - well happy enough to have eaten half of one of the trout - our first death. Will see if they keep at it or it was a random death that they capitalised on, other wise they are big enough to get turned orange.

I never had a marrom eat a live trout
But eat a dead one, to clean the water yes...
Have you checked you water perametters?

Water is good, pH has started to move down and is now 7 but Ammonia is 0, ites 0.25 and ates 10. I think it either was a random death or it got caught sleeping, the remaining half was floating when I got it this morning so I am thinking it got caught sleeping.

Never heard of a marron taking a live anything that is bigger than it, have studied marron out of an AP environment and they don't even take the Pygmies, they will eat dead things, trout would have swam off at first bite, and we know how fun and lively trout (sorry stu) marron wouldn't of had a chance of hanging on, I think just a dead trout

Nocky, Ive seen Marron Grab hold of a 1kg Trout, the fish jumped out of the water with the marron hanging on behind!! They are actually quite good at catching fish and reguarly eat tadpoles in the ponds.
As for the growth rates, in a typical pond situation I have found that at 2 years of age 20% of them will be between 250 -300gms, 25% will be between 200 - 250gms and 40% will be between 100 - 200gms.
I dont have the fast growing strain of marron either but I feed virtually every day. I imagine that growth in tanks would be much slower though.

that amazes me TM, I have never had trout with them before though, they don't touch the goldies or the PP for that matter, nor do they seem to grab the silvers in the dam, the opposite is the case in dam

I am pretty sure this one was grabbed alive as I have had no trout showing any health issues. Bluewindfisher also had a problem with marron grabbing his koi and goldfish and had to separate them. No sleepy trout caught today anyway maybe they learnt their lesson

Fact is unless someone wants to set up a camera nd run it underwater we won't get to see what they get up to all night!

With Marron becoming more active at night and the trout less so it's possible that the marron grabbed the trout whilst its still alive. Anyone whos been bitten by a marron knows they dont let go easily either. Those trout have spent the last year swimming around without any predators in the tank so they wouldnt be used to keeping a lookout for a pair of big black claws! They will learn quick though.

I have had all of my fish stock wiped out by marron before when trying poly culture in tanks, I have seen marine crayfish catch fish by using there legs as a cage to trap them and i have seen them dig blue swimer crabs out of the sand and rip them to pecies.

like you Nocky i have been trying for some time now to grow good numbers of marron in a closed system (in tanks) with out success, but i am still trying, there must be a way!

Grunta it is very hard, a couple of mates are doing it without AP and have heaps of PVC hides, but they seem to know how many mates they want in tank, they don't kill each other like yabbies or koonacs, just seem to die when over stocked, I have given up with marron for now as the time frame for about 8 marron is ridiculous and if I want a feed I will get them from the dam I just hate being defeated, but Grunta your water has to be perfect all the time one small change and they cark it, *frack* knows how they live in the muddy dam, another drama is food, I gave them about 1 marron pellet a fortnight, any more and it floated back to the top after a couple of days, also not good for the water, will stick with the yabbies for now (thanks Rick) you can't over feed them and they grow quicker, had a couple of aggressive ones, they were delicious, taking them out has seen to settle the others and havent seen any fighting or floating limbs for a while now