Backyard Aquaponics
A place to discuss aquaponics

So you have to fish them out of the tank and put them on their backs to figure out gender?! Dang :/

Nah Abdul... you can see a "berried" female fanning the water past her back tendrils...

And you can hold a yabbie up to sex them.... just easier to photograph them on their backs...

Hi Abdul
A pic of a yabbie in berry, a bit fuzzy but will give you the idea
Not sure how to load a video but will post more when I discover how

Over the past 18 months I have had up to 18 mature Yabbies contained in a 250 litre "Fingerling" tank. Even though they breed - with hundreds of baby Yabbies coming from many broods - I seem to always end up with six mature Yabbies. I think many of the young Yabbies died when I increased the salinity levels up to 3ppt for an extended period - believing I was helping my fish. Some of the mature Yabbies died a "horrible" death when I added a little PowerFeed - believing I was helping my vegies. As stated throughout this thread - Yabbies are very territorial - and kill each other at earliest opportunity - especially when moulting. I have also lost some with no apparent cause. I have found keeping Yabbies a fascinating experience - and I am determined to maintain a healthy breeding population in my AP System. Cheers - Colin

Hi Colin
I too think yabbies are great
I'm leaning towards keeping them in a separate system, you may have read other members who have had fish deaths due to long deceased yabbies found in pipework etc.
Originally started with 12 and some must have been in berry because within 3 weeks the population had exploded to about 300 over the last 6 weeks that number has halved due to cannibalism and some that have gone walkabout (I have found dried yabbies 300m from the pond) I should have culled a few for eating when the population was at its peak rather than let them eat each other.
I have a few ideas/theories about how yabbies keeping/breeding can be improved which I will be keen to implement when I set up a separate system
I see your from Mitcham! I lived there as a teenager in Dawe Rd, still know a few people in the area.

but even if they do eat each other wouldn't you just wind up with a few really big yabbies in the end?

Hi Abdul
In one of my FT (1500lt) I had about 60 yabbies, down to about 10 now and that consists of 9 medium sized ones and 1 large, I anticipate that soon it will be down to 1 extra large
Could be a big argument as to who eats that?

You may as well cook 'em now DR !!

Have to keep this post active... here's some more pics!!!

Note circled Yabby in my Half Wine Barrel System... 19 months old... born in 40+oC heat wave... only survivor of 70 rescued newborn. (This Yabby grew 10 times quicker than all his siblings... he ate ALL of them).

More Yabbies Pics:

Was going to post these on my thread but My love affair with yabbies started years ago especially raiding farmers dams out the back blocks (midnight shopping ) and getting heaps for a feed with the boys. So on the weekend I visited a mate and the opportunity presented itself again .
The last post is of a Marron from the tank I set up 2yrs ago with just a bio-filter, they were only 5cm (2inch) long when they went in and the filter is only a 20 liter bucket with sand and shade cloth.

Would love to have Marron over here in Vic!!!

tasty looking that!

Big claws for a Marron Gnash !