Koura Tank

[xstepheex]

Hi all,

Have done a read through the forums, so much info!
I have a Koura tank set up, running, ready, but i feel i am missing something.

Silk plants (I have heard they destroy real plants)
About 2 - 4cm of rough gravel and sand
Two small to medium rock caves
Heater set to 15 degrees (tank has been cycling for a couple of weeks already)

What else do i need before i pop the bad boys in?
Its a 100L with internal filter and hood, tank looks a little bare, i only have intention of keeping 2-3 in the tank.

Thanks in advance
Stephanie 

[Shilo]

Beware that more then one may lead to fighting especially if you have 3 in there and only a couple of hiding places.  Give them at least twice as many hides as you have Koura so they can pick and choose (my one has excavated 4 hides all of which he uses).  The more places they have to hide the safer they will feel and you will see them more often.

They will burrow under anything, in the case of rocks etc this means the rock will just keep settling deeper into the gravel as the koura digs underneath until the rock is buried or the koura's head is poking out of under it saying "Help me!" .  Best to have something under the rocks or decorations that will help support the item above the gravel.  For example 2 small rocks under the gravel supporting a each end of a larger one on top so the koura can safely burrow underneath.

Go with 4cm of fine gravel or sand.  They are burrowers and will be more comfortable if they can renovate their own homes to their liking.

They are escape artists.  If for any reason they dislike their home they will move and can climb any filter tubing etc.  Years ago I had one that used to go for a wander at night around the lounge but was able to find its way back into the tank before morning.  Make sure the tank is well covered with no gapes.

They are nocturnal so you may not see them out and about much.  After awhile they will come out at feeding time if you train them:  feed them at the same time every 2nd day or so by putting some food just outside their hole.  Eventually they learn that its safe to come out a bit further etc and after 6 months or so will be their to greet you at feeding time.  They will also recognise a hand as a good thing (food bringer) so never chase them or try to catch them by hand, let them think a net is the scary monster instead.

Add calcium to their diet or use a high calcium food. They will consume their own shell after a moult but of course each new shell is bigger then the last one and they need calcium to produce it.  I feed mine with Repashy Veggie Burger and add a small sprinkling of extra calcium when mixing it up (both I got for my Blue Tongue skink) , the meat portion of its diet it gets by scavenging left over food from the fish.

Lose the heater, 15C is their optimum temperature but they are quite happy from 5 to 18C.  Your main problem is going to be during the summer when you can't let the water get more then 20C, a chiller is the only practical way of doing this - floating frozen bottles etc is next to useless for more then a day because you will be swapping bottles out every few hours day and night.

Use dim lights as they are nocturnal and strong lighting will just send them into their hides.

 

[kiwiraka]

Hi there,

First off its good that you've done your research, always helps

A heater isnt necessary in a yours tank as they need coldwater. All heters do is heat, if you need to cool the water  you'll need a chiller. Where are you located? The further north you live the moe likely you are to need to look at cooling your tank.

Koura are much less demanding about water volume than fish, so 2-3 should ll be fine in a 100 litre. Although you may want to look at more caves and rock arrangements. Koura can be territorial and cannibalistic so they need plenty of hiding places. Wood is also good, for both cover and as food.

Shilo's beaten me to it  All good advice in post about

[xstepheex]

That is awesome thank you so much!
Guess i will be rescaping for them for the next week or so!
Is a chiller just as accessible as other aquarium things (from LPS?) Never thought i would need one of those as i have always kept tropical!

[kiwiraka]

Chillers are a lot more expensive than heaters and are more of a specialist item. Only seller of new chillers I'm aware of is HFF. But  if you want a more affordable chiller a secondhand one off trademe is a better option. What area are you in? 

[xstepheex]

 What area are you in? 

Wellington CBD, probably won't need to worry about one for the next few months, its pretty damn cold here!|
Gives me a bit of time to look into getting one which is good, but obviously i am not going to need a massively huge one for a 100L?
Whats the noise level like....? 

[kiwiraka]

Should be alright til summer  

The noise isnt too bad from my smaller chiller, definitely  not bedroom furniture though. I'm not looking forward to finding out how loud the 1HP chiller is 

[xstepheex]

bugger, i love having the tank in the room!
ah well, guess i'm in for a busy and expensive weekend! 

[kiwiraka]

bugger, i love having the tank in the room!
ah well, guess i'm in for a busy and expensive weekend! 

Welcome to the wonderful world of NZ native fish keeping 

[xstepheex]

thanks for the noisy welcome 

will update once everything is good and going and have sourced some koura!
thanks for all of your help @kiwiraka and @Shilo!! 

[Shilo]

_{Budget up to $500 for a second hand chiller & keep a weekly eye out on Trademe so you don't miss out.  1/10  up will do for a 100ltr tank.  They should go beside the stand and not underneath it unless the stand is open ended and has a lot of air movement.   The chiller will pump out quite a bit of heat into the room during summer so leave a window or 2 open. You could get away without a chiller if you have an air conditioned room & don't mind room temps being down to 20C during the summer - but it will probably work out cheaper running a chiller.}

 _{Koura are easy to find - just go to any small stream in native bush at night and shine a touch in the water.  Use 2 nets (warehouse long handled butterfly nets are good & cheap), one sat behind the koura and the other one in front slowly sweeping up to it.  Chances are the Koura will flick itself backwards & into the rear net.  When collecting just remember that its illegal to take any wildlife from DOC & regional park land.  Lastly don't go for the biggest meanest one you can find as the smaller they are the faster they will get used to a tank and the better chance of survival.  Any size below 3" is good - they grow fast.  Also if they are missing a limb or claws etc, don't worry about it as they grow back.  My current one had no claws when I found it last year but now has a couple of mean munchers that I'm starting to be wary off!}

[xstepheex]

Awesome! Thanks @Shilo!

Have had a wee look online, will hold off on a chiller for winter i think, house gets pretty bloody cold already!
There are hundreds of them up at my partners farm over the Wairarapa, we have caught them before with ease with just our hands  a net is probably a safer option though!
Such cool little creatures, I am really looking forward to keeping them.

Didn't want to jump ahead of myself and get a couple home to realize the tank hadn't been set up how they would like it the most.
Is there anything that would make an ideal tank mate (fish or shrimp) that could be put in there with them?
The tank is obviously quite small at 100L and wouldn't want to overstock or upset the precious.

[Shilo]

Shrimp are good - just make sure you have a sponge or fine netting over the filter inlet (my shrimp are always going for hydro-slide rides into the sump).  A few Inanga's will suit the tank well and since they live in the upper water column will keep out of the way of the koura & their pincers.  A couple of Redfin or common bullies are another option, they are real characters and although share the same area as the koura, have evolved alongside them and will keep out of the way.  Native NZ mud snails (those tiny ones) will also be good and help keep the tank clean.

Don't put gold fish or white cloud minnows in the tank with koura since they don't know to keep away and will get damaged from the claws.

[xstepheex]

Don't put gold fish or white cloud minnows in the tank with koura since they don't know to keep away and will get damaged from the claws.

Glad you said that as mountain minnows would have been my first go to... 

Are these also all accessible in the same place as Koura? 

[Shilo]

Yes there should be native fish where the Koura are.  Again best way to check is to go at night (1hr after dark or later) and do some spot lighting with a torch.  The best streams are ones which have access to the sea somewhere down their waterway (even 100+km away) & no huge waterfalls or inaccessible culverts downstream which fish can't pass.  This is because most natives have a marine stage (think whitebait)  If its in a native bush area it would also have a lot more life.

Here's some info on the types of natives and where they live:

http://aquariumworld.nz/databases/2-new-zealand-native/

https://www.niwa.co.nz/freshwater-and-estuaries/nzffd/NIWA-fish-atlas/fish-finder

https://www.facebook.com/nznativefish/  

 

[xstepheex]

Thanks @Shilo, have just spent all morning reading up on those links.
The information in my head right now is overwhelming haha!

[Silverdollarboy2]

There is a Native Fish Database, with information on koura aswell.

EDIT, I see Shilo has already posted it.

 

Edited June 9, 2016 by Silverdollarboy2

[xstepheex]

Got him home, in all of his glory!
Also managed to catch a couple of whitebait and a cockabully.

Seeing them up close is so crazy! Such cool little creatures!

I would like to formally introduce MR KRABS

Edited June 12, 2016 by xstepheex

[Pennyleigh17]

They make such unique and interesting pets with great personalities! 

How does he do with the fake plants?

I can't have any plants at the bottom of my aquarium, real or fake without my guys destroying them. Yes plastic and silk plants included get shredded into tiny pieces!

I like to add oxygen weed occasionally for them to destroy and munch on if they feel the need and I find they don't tend to touch the plants the float.