Backyard Aquaponics
A place to discuss aquaponics

Do you know what's going on here? Looks like rust or holes in the shell of the yabbies. I think I saw a 3-4mm long work crawl out of one hole. Have isolated and salted to 5ppt, and system to 5ppt while there ain't no fish in there
Any ideas /recommendations?

I believe it may be temnos - http://www.fish.wa.gov.au/docs/aq/aq001 ... 5.php?0309

Simo posted something similar recently but concerning Marron. See viewtopic.php?f=2&t=10756

The rust spots are shell rot and there is not real cure for it. You can salt dip them in 50% sea water for an hour and put them back in the tank and repeat every 2 days. Generally, they will die from it. Alternatively, increase the water temp to 25C and increase the calcium hardness to 300mg/L and form the crayfish to molt. By now it will have a few secondary bacterial infections which any stress may kill it.

The worms are opportunistic, more than likely Annelid Branchiobdellida or hydras. They have a low tolerance to salt so the bathing will kill them but you will need to repeat every 7 days as new eggs hatch.

Whats the pH?

Really? Bugger. Ph is low, lower than 6.5. I was gonna chuck them uni a pond, but maybe I'll just put them into a freezer. Will the worm pose a threat to fish if they are healthy?

Add some cuttlefish bone for it to chew on.

Can help speed up the process to shed the shell

Hey FB,

Your pH is way too low for yabbies, I had yabbies for years and they didn't like it if the PH got below 7.0

They were always healthy and bred like rabbits when the pH was up in the high 7's, even in the middle of winter.

P.S. Mine had Temnos (brown spots/eggs on the underside) when I first got them, I tried salting a few times, but they always came back, even when the pH was higher. The Temnos never affected them, it's just unsightly, but that's only a concern if you were a commercial grower trying to market them.

Cheers.

That's a very handy tip Earthan Group...

I've just read the Fisheries Dept' link you posted FB,



I had the yabbies in a couple of 600L aquariums with crystal clear water and I was told by both a Marine biologist from Fisheries, and an old farmer, that the reason my yabbies kept getting Temnos was because my water was too clear, must be some truth in it.

But I'm dribbling, Temnos aren't your problem anyway... so, what the others said about calcium etc!

Thanks guys, I've put 2 worst in the freezer, the last will go into a pond tomorrow, after a little bit of a salt bath

A PH of 6-9 is acceptable for yabbies although the optimum range is 7-8.5.

Extreme low or high PH will damage their delicate gill membranes, thus reducing respiration and affecting health.

Amino acids contained in high protein foods are the building blocks to assist in growth and enlarge the body so to malt. Although malting will not get rid of the problem you have. It will eventually attack the eyes and they will become blind and eventually be eaten by others.

What filtration do you have FB?

Get rid of them anyway sorry.

I have 600l gbs with 2 x2000lph pumps going thru, also has 3 abfs over winter. They were all grouped in a 'dead' corner with a bit of poo etc. never had a ammo reading all winter

Shouldnt be a water quality issue then.

I had one about 10 years ago do a similar thing cant remember what I did or what I decided the cause was thou.