NZ Koura - Freshwater Crayfish

[newaqua]

Hey All.

Just curious if anyone has held any of these in tanks inside before. Would be interested to know, and if so, what sort of temperatures/water quality do you have them in?

I ask this, as I was talking with a friend who believes that they would be fine in a tank of up to 22-23 degrees, which is a good 5 degrees above their summer time peak of water temperature.

Any comments/suggestions would be appreciated.

Thanks

Mike

[newaqua]

Oh, and if anyone knows of Tropical creatures like Crayfish that are available in NZ, I would love to know about them.

[twinkles]

I've got 3 and there's alot of other people here who've got or had them, have a browse through the native forum category.

I keep mine under 20deg, but they're in a tank with smelt who are really temperature sensitive. We often find them in the warm parts of the river, still sunny rock pools on the edges, so they can probably deal with a little more heat if the water quality is good enough. It might lower their lifespan though. What are you wanting to keep them with?

The two i've had for a while are really friendly, out and about most of the day and run out as soon as you drop food in the tank, but our newest one is very shy still and doesn't come out when we're around much. They've all got their own little houses where they've moved gravel and stones around under the driftwood and big rocks to make nice hidey holes. They come in heaps of different shades and patterns, so we've got one dark one, one pale one with geometric patterns, and one with tiny spots all over it, easy to tell apart at a glance. They will eat each other if they haven't got enough space each and places to hide, ours are in a 4ft and i'm planning on getting something bigger before they grow too much bigger. Grow to about 16cm I think, and they shed their shells frequently to grow bigger - always makes me panic and think ones been eaten lol.

Mine like fish flakes, sinking shrimp pellets, tiny chunks of dog roll, bloodworms, any live food and bits of the plants in their tank, both the brown old leaves and fresher bits, and they will climb up out of the water in the evening to search around the plants above the waterline. Some koura eat fish but we haven't had any problems yet with the bullies who share their tank.

[twinkles]

Here's my pale girl with shapes down her back, under blue tank lighting -

And here's a wild one in his home -

That's in a little forest stream where there are billions of them, one every foot or so. They seem far more numerous in clear, cold shallow forest streams, with shaded water and lots of leaf litter and debris, than in the sunny, warm, bare rock river edges, but Stella is the expert and could tell you more about what habitat suits them best and how adapatable they are.

[newaqua]

Thanks, Im looking at getting one to keep with a mixture of other fish, Albino corys, Sterboi Corys, Jurupari eartheaters, bristlenose, and an angel. Do you think that would work?

[zuri08]

No not a good mix. Completely different set ups and temps ph etc the koura wouldnt like anything over 22 and the angels wouldnt like anything under 26

[twinkles]

I couldn't say for sure. They're meant to be happiest between 10-20deg, but I have heard of other people keeping them in tropical tanks up to 24. You could set up a tank for one with low temp tropicals though, guppies and the like? Putting them with that mix of fish they'd be likely to eat the corys

[blueether]

Paranephrops zealandicus, southern koura:

16 deg looks to optimum, and it looks like the L50 temp is about 21 deg over 12weeks, that is 70% died within 12 weeks at a temp of 22 deg

Emphases mine

http://www.sciencedirect.com/science/article/pii/S0044848605003716":1ewrbaz4]Abstract

Two 3-month experiments were conducted to investigate the effects of temperature and water calcium concentrations on growth, survival and moulting of freshwater crayfish (Paranephrops zealandicus). Both experiments were conducted using three replicates of five treatments (water temperatures of 14, 16, 18, 20 and 22 °C for Experiment 1 and water calcium concentrations of 0, 5, 10, 30 and 80 mg/L for Experiment 2). Growth rates increased with water temperature (maximum specific growth rate = 0.57) but were unchanged with increased water calcium concentration. Variability in growth rates decreased with increased water calcium concentrations. Survival decreased as water temperatures exceeded 16 °C and increased with water calcium concentrations above 10 mg/L. Inter-moult period decreased from > 90 ± 20 days at water temperatures of 14 °C to ∼ 40 ± 10 days at water temperatures > 20 °C. Moult increment of the crayfish was unaltered by either water temperature or water calcium concentrations. The optimum water temperature for productivity under conditions employed was 16 °C.

[twinkles]

Brilliant info blueether

So not even with guppies. Mountain minnows are happy at those low temps I think? Ours are with smelt and bullies.

[blueether]

What, your WCMM are with your smelt and bullies? :digH:

[twinkles]

Lol, minnows wouldn't last long with the bullies

[zuri08]

I knew most natives wouldnt handle higher temps shrimp dont tolertae warm water either very knowledgeable blueether :smln:

[blueether]

... shrimp dont tolertae warm water either

I believe that they can cope with ~25 deg if there is high O2, they will die at 27 deg

very knowledgeable blueether :smln:

:oops: just know how to use google

[Sophia]

hello... everybody hold on to your drinks, I'm just moving the thread to the natives section..... :cofn: