Jump to content

Blue


kiwiraka

Recommended Posts

Wow. That is an amazing colour! Natural variant or ...?

Yes natural varient (See Adriennes links :) )

Apparently in some populations up to 25% of the koura carry the blue gene but it only appears occasionally due to heavy predation since they don't tend to blend in too well. Although they can be much more common in deep lakes due to the low light penetration.

I found it in the Akatarawa river, just after a flood. I'm guessing it got washed out of a smaller stream since it likely wouldn't last long with trout in the vicinity.

Pretty cool little character doesn't seem to like tank mates so he's currently in his very own 4 foot tank with a Sunsun 303B.

 

You didn't leave that in the stream did you boy or girl 

Haven't checked, although I definitely will in the near future. I would love to have a go at breeding it :D

I'm thinking best method for this would be to wait til it's bigger then get Koura that are smaller as I don't want to risk him/her getting injured or killed...

 

Link to comment
Share on other sites

Beautiful, hopefully you find another so you can breed them.

It sure is :)

Not quite sure on how genetics work but since it's a recessive gene (and if my 5th form genetic understanding is correct) if I breed the blue (bb) Koura with a normal coloured (No recessive blue gene) Koura (BB) all the offspring should carry the gene (They should all be Bb) but not show the blue colouration. Then if I breed those offspring with the blue cray hopefully 50% will be blue (50% should be bb 25% Bb and 25% BB). Or if I breed two carriers (Bb+Bb) 25% would hopefully be blue (bb). All offspring of two blue Koura should be blue.

Although finding another blue specimen would be so much easier :P

Someone else will have a better idea but one can hope ;) Now to get it to breed...............

Edited by kiwiraka
To clarify my explanation
Link to comment
Share on other sites

Not quite right let's say the blue gene is b and the normal is B the blue crayfish must have bb a non blue crayfish will have Bb or BB if you breed it with BB none will be blue if you breed it with Bb about one quarter will be blue 

I was assuming the normal coloured Koura was not a carrier and was BB. I think the way genetics are taught in school compared to uni is very different, in school you're taught one gene is responsible for colour, but I think it's actually a combination of genes (upward of 10?).

Maybe someone with a bit more experience with breeding and genetics can clarify this?

 

Link to comment
Share on other sites

Honestly - it could be anything, i suspect the blue colour isn't directly coded for by a gene, but instead by a lack of ability to break down certain proteins causing the expression of a blue pigment (see: http://kb.osu.edu/dspace/bitstream/handle/1811/5656/V71N06_363.pdf?sequence=1 ). It may also be an environmental thing, as i've mentioned before the blue colour morphs are more common in deep lakes due to the light penetration meaning that blue crayfish can camouflage better in deeper environments. If it moults and doesn't produce a new blue exoskeleton then it is like an environmental factor influencing, while if it continues to produce a blue exoskeleton it may be genetic. 

The australian freshwater crayfish has a blue morph which is autosomal recessive (recessive gene on a non-sex chromosome) - this follows a mendellian ratio (3:1) if we assume normal inheritance and ignore possibilities of incomplete or co-dominant genes. Yet some studies attribute the coluration to diet and environmental cues.

http://www.bioone.org/doi/full/10.1651/0278-0372(2000)020[0025%3AEFTIOA]2.0.CO%3B2

In other words, we don't know enough about it yet, so if someone can breed it successfully i'll be bloody impressed.

 

Link to comment
Share on other sites

In April Kirkendoll's "How to raise and train your peppermint shrimp" (the book I have mainly been following for my breeding attempt) she has about 3 pages at the back in regards to reef lobster. Obviously not the same as this but it could be helpful to get you on the right track with it anyway (if the time came and you got it breeding)

Link to comment
Share on other sites

In April Kirkendoll's "How to raise and train your peppermint shrimp" (the book I have mainly been following for my breeding attempt) she has about 3 pages at the back in regards to reef lobster. Obviously not the same as this but it could be helpful to get you on the right track with it anyway (if the time came and you got it breeding)

Thanks for that :)

What about painting the back of the tank blue or putting a blue background on the tank?

If it loses it's colour I'll probably do that, but I want to see whether it's genetics or habitat that's causing the colour.

Link to comment
Share on other sites

I was joking! :D Not a fan of the coloured gravel either! (especially fluoro pink, urrrghh, shudder)

But the experiment could be interesting, whichever way you try ('matching' or contrasting environments). I wonder if koura can even see in colour, or do they see in grey-scale or even in wavelengths we humans don't see? Anyone know?

Link to comment
Share on other sites

The good thing about breeding koura is they do all the work for you.

http://www.rodmorris.co.nz/keyword/freshwater/i-wR3zFzs/AA

Until they get released and the mum gets hungry ;)

I was joking! :D Not a fan of the coloured gravel either! (especially fluoro pink, urrrghh, shudder)

But the experiment could be interesting, whichever way you try ('matching' or contrasting environments). I wonder if koura can even see in colour, or do they see in grey-scale or even in wavelengths we humans don't see? Anyone know?

I was hoping you were ;) Although I could try turn the Koura pink :P

I'm assuming they would, isn't eyeshine a sign of what colours they see? Koura have orange/red eyeshine, red light is being reflected and they see the rest of the 'visible' light spectrum?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...