Keeping Freshwater Crayfish (Yabbies, Koonac, Crawdad) Using WWM   1/23/07
I live in Australia, in Australia we call freshwater crayfish "Yabbies" or "Koonac".
In America I think they call them "Crawdads", I wanted to find out some info on keeping them.
Thanks
Dylan
<Mmm, yes... See WetWebMedia.com re... the indices, search tool... with these terms... We have articles, FAQs files re these crayfishes. Bob Fenner>

Differences between lobsters/crayfish/species....?   1/26/06
I recently purchased an "electric blue lobster" from a trusted pet store, but when I search the internet for
information, I find many different names/species/varieties.
<Yes... you start to understand the value in scientific names... many organisms have more than one common moniker, and these are often applied to more than one species>
I called the pet store to see if they knew the Latin name
of the species they sold me, but to no avail.  I have searched for hours for a way of determining what it is that I have
actually purchased.  Could you enlighten me as to what the physical differences are between lobsters versus crayfish,
species of crayfish,
and how to identify what variation I have?
<Can... a beginning... both common names are applied to a few groups of crustaceans... marine and fresh... that is, the terms crayfish and lobster are often used for different taxonomic groups... They are not definitive as to their systematic classification>
I also wanted to commend you on the fantastic website you have here.  I am extremely impressed (almost a little
overwhelmed) by the enormous amount of information you supply.  Thank you!!
Tammy
<A photograph will be useful here. Have you read through the freshwater and marine articles on crayfish and lobsters posted on WWM? There are some pix, systematic information, identifications there. Bob Fenner>

Shrimp/Crayfish
As a Valentine's Day gift for my two sons, my husband purchased two African Clawed Frogs, while the man at the pet store was trying to catch the albino frog, he came across a little guy my oldest son likes to call "Pincher."  He gave him to us for free since he wasn't sure what he was.  I think he's either a shrimp or crayfish of some kind.  How do you tell the difference between the two?  He's about 1 inch long with two pinchers and a grayish/brown color and a flat fan like tail.  I would greatly appreciate your answer.  Thank you.
Susan
<Hi Susan, generally crayfish are larger than shrimp.  It's hard to say without a picture.  Does it look like any of these:
http://www.thekrib.com/Fish/Shrimp/
Regards, Gage>

Shrimp/Crayfish
I am going to try and get a picture sent to you of "Pincher".
<Awesome>
I looked at the site you sent and couldn't find any one shrimp that looked enough like him, they all resembled him but not enough for me to say he's a shrimp.  The only other way I can describe him is he likes to hoard food, he at first didn't mind the African Clawed Frogs but then suddenly started to chase them around and even pinched off some of the little albino frogs toes.
<Maybe a crayfish, they are pretty aggressive.>
He has dug himself a little home in the gravel under a decoration in the tank.  I know this probably doesn't help you much more, so like I said I'm going to try to get a picture sent to you.
Thanks for all your help.
<In my experience freshwater shrimp will usually do their best to hide and avoid confrontation with anything and everything.  This sounds like a crayfish to me, I named mine "fish pinchin' crawdad" I'm working on a country song about him. A picture would be great. Regards, Gage>
Susan

Blue Water Lobster
Dear Bob
<Hey there - I'm not Bob, but I am the freshwater invert-obsessed Sabrina - hope I can shed some light on your new critter.>
We have a Blue fresh water Lobster but are having a few tiny problems with him/her and wonder if you may have any answers?
<Hmm....  I've seen a few different animals that fall under this name, any of which might be the critter you've got.  It could be any of a handful of Procambarus species (crayfish) that is blue or has a blue form; or could be either of two blue Macrobrachium shrimp species - M. rosenbergii from Thailand or another species from Mexico.  A picture would go a long way to identifying it, if you've got one.>
He is attacking the big Plec and ripping the Pleco's fins.  He has also started recently to kill the smaller fish by grabbing them with his claws.  
<For any of the species above, this is quite normal....  they don't play well with fish.>
Is there any way we can stop this?  
<No, not really.  Separating him from the fish is pretty much the only way to end the carnage.>
We have now put in a ceramic pot and cave entrance to give him a safe cover, will this help combat the problem?
<No, unfortunately.  Regardless of which of the above critters it is - they're aggressive, and fish-hungry.>
We feed him on prawns
<Excellent food for 'em>
and specially bought crab cuisine which states is ok for Lobsters.  Should we be feeding him anything else?
<Ocean Nutrition's frozen Formula One is a good food choice.>
We have looked everywhere for a book on Lobsters but have had no luck.  
<Do some google searches on 'blue crayfish' and 'blue prawn', as well as the above Latin names.>
He is now about 4 inches long without counting the claws.  
<And will grow about twice that>
He is shedding about every three to four months and eats his shell afterwards.  We have had him now for ten months and has shed three times.  He is showing signs of being due for another shed as he is constantly laying on his side and acting as though he is dead, which we have noticed he does this just prior to shedding in the past.
<I don't think that's a good sign....  perhaps try adding iodine to the tank (use Kent's marine Iodine supplement); one drop per ten gallons every week.>
He is constantly shoveling the stones about, we have had to change from a sand bottom as he kept blocking the filter with the constant moving of the sand.  We now have an undergravel filter.  If you have any information that will help our Lobster Rocky to have a good life, would you please be so kind and inform us?  
<I am sorry for the news that he'll be always incompatible with most fish; he may warrant a tank of his own.  There are a few fish compatible with these animals; do some google searches to try to find out exactly what you've got, and hopefully that'll help you out some.  Wishing you well,  -Sabrina>
Thank you in anticipation.  Yours sincerely  Mr. John Edwards