Murray cod
- Thread starter ashdavid
- Start date
Previously I'd never really seen many in private aquariums, I had seen a couple in large aquariums(Melbourne aquarium etc.) and they seemed reasonably responsive to 'spectators'. I had seen a few Sleepy Cod in LFS's and yeah all they seemed to do is lay in a corner and do nothing! Knowing their nature I thought I may have the same problem with the MC, but had always wanted one so got it anyway!Steve_89 said:
Mine does spend a bit of time lazing under a log or hiding in a hole, but is still very responsive to people outside the tank. He will come up the glass when I approach the tank, and move around searching under the wood for yabbies and things, he digs burrows in the sand(this is funny to watch). Maybe not as active as a mid water fish but just as active as any other bottom dweller I've had(besides some catfish). The big one at Boronia aquarium(pictured above) was very responsive too(he didnt really have anywhere to hide though), it came straight up to the glass when I approached and I ran my hand across the top of the tank and he followed it across. But I've also had a few guys contact me and say that all theirs does is hide and the only time they get to see it is if they disturb its hiding position? Maybe its just luck of the draw?
This is all part of the same problem. What problem? A lot of Murray cod can be quite timid for the first few months of life. Be patient! Most Murray cod, upon reaching a certain size (20-30cm, which can be achieved in less than a year) suddenly realise there's nothing to fear, and that they're the boss of their tank, and suddenly become very confident and outgoing.
Most of the 30cm+ Murray cod I've seen in tanks have been stunningly alert and interactive fish - always in mid water, always turning to face you when you walk up to the tank, and always begging to be fed. Mine smashes goldfish (when I give them to him) in 3 seconds flat and he also takes grasshoppers off the surface in big surface strikes. Awesome fun. My Cod is about a year old now and is 30cm - I could have easily grown him even larger in that time but I'm trying not to, so that he'll last in my 5 foot tank for another year.
Murray cod are NOT to be confused with Sleepy Cod (Oxyeleotris lineolatus). Sleepy cod are unrelated and are in a completely different genus and family. Sleepy cod WILL simply sit there and not do much.
RE temperatures, Murray cod would be OK in a 27 degree tank with tropicals. I would be cautious of taking the temp much higher though. I noticed somebody said their cod tank got into the low 30s. In my opinion this is too high - it is pushing the upper temperature limits of Murray cod - and should be reduced somehow. So, in short 27 degrees would be OK if you wanted to keep a Murray cod with tropicals. By itself, 24 degrees is a good temperature for Murray cod, and there's no need to go higher.
Actually, the largest crayfish in the world is the Tasmanian Giant Freshwater Crayfish (Astacopsis gouldi). Reliably recorded over 80cm in length and up to 6kg in weight in the early days. Such giants would have been many decades old however and due to many years of overfishing (now banned thankfully) no longer exist today. The Murray River Crayfish (Euastacus armatus) is the 2nd biggest crayfish in Australia after the Tasmanian Giant Freshwater Crayfish. Murray River Crayfish are probably the 2nd biggest crayfish in the world too, but I can't confirm that.
And yes, big Murray cod are probably the only predators of big Murray River crayfish. Big crays are still vulnerable after moulting when their shells are soft. Smaller native fish would get stuck into juvenile Murray River Crayfish .
Wow, I'd never actually heard of a Tasmanian Freshwater Giant Crayfish! you've got me intrigued, I wonder if its possible to get hold of one for an aquarium?Goodoo said:
Thanks for posting the MC info too
Tasmanian Department of Primary Industries Fisheries Site should have info on them.
They are protected now so they are probably VERY difficult to get hold of, and would almost certainly require a permit.
The Giant Tasmanian Freshwater Crayfish is an awesome creature, and is severely threatened by massive siltation caued by $#@#%$%^$ clear-felling logging by good old Gunns we-own-Tassie-and-have-bribed-the-politicians-and-can-do-what-the-f***-we-like Limited.
Simon
They are protected now so they are probably VERY difficult to get hold of, and would almost certainly require a permit.
The Giant Tasmanian Freshwater Crayfish is an awesome creature, and is severely threatened by massive siltation caued by $#@#%$%^$ clear-felling logging by good old Gunns we-own-Tassie-and-have-bribed-the-politicians-and-can-do-what-the-f***-we-like Limited.
Simon
I hear you thereGoodoo said:
Here is some info I just dug up on the Giant Tassie Feshwater Cray(look at those claws!
) :
Taken from: http://www.arkive.org/species/GES/i...d_freshwater/Astacopsis_gouldi/more_info.html
An interesting thing I just read - the humble yabby (Cherax destructor) is an introduced pest in Tassie!
Sorry! I found this beauty and couldnt help adding it to this thread!
This is from Fish Base and the stats say he's 110cm and >20kg
This is from Fish Base and the stats say he's 110cm and >20kg
So you can just imagine what clear-felling does for them.... :-(
And you can imagine what those nasty introduced Trout do to this vulnerable life stage.
