Backyard Aquaponics
A place to discuss aquaponics

Is anyone having success with Murray Cod?

I bought 100 from Rupe in January from memory and the bloody things are eating each other. Went well to start with, but as soon as the dominant ones gained weight they started to snack on the smaller ones. I have 3 inch fish eating 2 inch fish!

I know the obvious thing is to keep them well fed (which I do) and to grade them. Does anyone have other ideas? I was thinking of throwing in a load of mosquito fish from the local creeks to keep them occupied but I'm concerned about introducing disease.

I've got Murray Cod and I think they may be eating each other as well. I'm not totally worried as I figure that I will end up with a few large ones swimming around.

I have introduced a heap of PVC hides Ito the tank which I thick helps.

I don't think my cod feed on the pellets too often. They just don't seem too be too excited by them. I guess the must at some stage though when they are hungry enough.

Hides, grading & crowding are the only things I know of Geoff....

As you can't really crowd them at the moment... and probably can't grade them either... (even if you could, they're likely to just do the same later)...unless you can get the bigger ones on their own..

So... I guess hides might help... let the smaller ones catch up...

Good chance they'll dash out of their hides to grab some food.... and become a snack anyway...

More live food. Compost worms, BSFL etc.

would a feeder fish help, like minnows?

If you feed them fish they get more used to eating fish.

I'm setting up a modular type tank system, could this be a good idea for cod as I could grade them easily?

I wont be starting with cod but I wouldn't mind experimenting when my system is aged.

Cod like eating other fish. I don't know if starting out with silvers and putting the cod in after the other fish are too big might slow them down, not being the biggest in the tank etc.

This is George.


This golden perch was in his tank for a few hrs and all george wanted to do was work out how to get it into his mouth.

Hides have to be small as the larger cod will just pick off any smaller one that swims past them.

Having a modular type tank setup will keep the fish seperate. I will have 4x 160l barrells with SLO setup between each tank like a teir setup meaning the water will cycle through each tank. Still working on ideas for my tank setup but that's the gist of it

While I can't be exactly sure due to my water colour, I don't think I am having trouble with cannibalism. There seems to be a balance with crowding the fish. Overcrowded = aggression/fighting which causes injuries and can lead to cannibalism. I also don't use feeder fish for the reason Duff suggested, they get used to fish snacks. I don't believe in hides as this creates an ambush point. The only hides I have in the large tank are a 25mm pipe about 1200mm long which they can get under but not in(joins the tanks), the backup pump and the airstones. I have found them quite tolerant of the cold IF you have the water volume. I lost my first lot by playing around too much trying to keep the water warm and in doing so the temps in the 600l tank would go from 18o(heated) to 6o on the first pass through the growbeds the next morning. With a 2000l and 600l set of tanks, setup pump from sump(2000l) to growbeds back to 600l tank which overflows to sump and left to pump all night the water has got down to 8o but it only varies approx 3-4o in 24 hours when air temps vary up to 25o. My small cod are still feeding well from the surface at 14o. I have cut feeding back but still usually manage three feeds a week. I hope you can sort them out, they taste fantastic.

cheers

cod fish

GOD ! - I want a cod !!

How long have they been down at 8c? Last year mine began getting fungus infections and dying once they spent about a week below 10c. When I kept them above 10c they were fine.

Just jumped on my PC as iv been using my Iphone all day and seen the photo of George properly!!! didnt really see it too well on tapatalk.

Geez thats a nice looking Fish!!!!!

GW Duff!!!

They grow really fast if you feed them fish.

We just sold 22 Murray Cod to a Fish Aquarium. I need to grade my trout and the Cod were just eating each other.