Yabbies as Pets (Australian crayfish species)

Does anyone in this group own pet yabbies? I have had them for about
five or six years. Some tips for them a

* Let them get above the waterline regularly so their shell can harden
* Feed them veges such as potatoes, carrots from time to time, and
other 'goodies' such as meat/seafood, not solely a petfood diet
* Have them live with fish and other yabbies, but only from birth/date
of purchase

They are cute to watch, but don't try to pat or stroke them- they're
not quite like dogs or cats!