Jump to content
Sign in to follow this  
Disciple

We are having a debate about the term Pure. Please have your say.

Recommended Posts

Disciple

Ok people time to make history we will start with a simple one for this we just need a yes or no answer we will define the term pure as it will relate to shrimp this is only single gene line shrimp no hybrids ie tibee, pinto, misch etc. Going forward in our hobby pure in reference to shrimp will mean the following any shrimp that produces and has produce all offspring of the same genetic make up as the parents for 3 or more generations shall be deemed pure.

These are some interesting responses that we have had.

1. Yes! But I'm not okay with just 3 generations to call it pure. As I told earlier in another discussion, I've been getting only crs offspring in my crs only tank for the past 2 years until now(2 golden bees after more than 10+ generations approx, meantime no new shrimps were added in the past 1.5 years)

2. Perhaps the term "true-breeding" (or pure-breeding) is more useful than pure, most if not all these things are hybrids after all. There are no wild species that correspond to a Taiwan/Shadow bee, for example. The true breeding stability comes from dilligent selection and line breeding for a given trait until no other traits occur. That's the hard part of the work and down to the quality of the breeder.

3. Well pure means pure, not 80<90 %.

Share this post


Link to post
Share on other sites
fishmosy

Yes from me.

Share this post


Link to post
Share on other sites
OzShrimp

confused about what you are asking for a yes or no answer and 3 options ? 

Share this post


Link to post
Share on other sites
jayc

I think the question is ...

"any shrimp that produces and has produce all offspring of the same genetic make up as the parents for 3 or more generations shall be deemed pure."

 

3 generations is not enough to deem any shrimp as pure if it has any mixed gene.

Take this article I wrote about genes for example. http://shrimpkeepersforum.com/forum/topic/7637-tibee-taitibee-pinto-mischling-f1-f2-terms-explained/?do=findComment&comment=93580

All it takes is for 2 shrimps carrying the recessive gene in the F2 or F3 generation to produce an unwanted gene.

The fact that you might not see it for several generations (or years) is just down to odds/chance of the shrimps carrying recessive genes mating.

Once a pure shrimp is mixed and carries genes of another type of shrimp( eg PRL with golden bee genes), then it will take many, many generations of breeding, and culling golden genes out before you would even consider it pure again. 

The fact that it might breed True for many generations, just means that the odds are high for the dominant gene.

The fact that it might breed True for many generations, also does not mean it is Pure. Cause, as I mentioned, it just takes that slim chance of two PRL recessive carriers of golden genes to spit out a Golden bee. And a Golden bee is not a PRL.

 

Edited by jayc

Share this post


Link to post
Share on other sites
OzShrimp

ohwell i agree 3 generations is not enough !

Share this post


Link to post
Share on other sites
fishmosy

I think the question is ...

"any shrimp that produces and has produce all offspring of the same genetic make up as the parents for 3 or more generations shall be deemed pure."

 

3 generations is not enough to deem any shrimp as pure if it has any mixed gene.

Take this article I wrote about genes for example. http://shrimpkeepersforum.com/forum/topic/7637-tibee-taitibee-pinto-mischling-f1-f2-terms-explained/?do=findComment&comment=93580

All it takes is for 2 shrimps carrying the recessive gene in the F2 or F3 generation to produce an unwanted gene.

The fact that you might not see it for several generations (or years) is just down to odds/chance of the shrimps carrying recessive genes mating.

Once a pure shrimp is mixed and carries genes of another type of shrimp( eg PRL with golden bee genes), then it will take many, many generations of breeding, and culling golden genes out before you would even consider it pure again. 

The fact that it might breed True for many generations, just means that the odds are high for the dominant gene.

The fact that it might breed True for many generations, also does not mean it is Pure. Cause, as I mentioned, it just takes that slim chance of two PRL recessive carriers of golden genes to spit out a Golden bee. And a Golden bee is not a PRL.

 

So if I'm reading this right, and based on my limited knowledge of Mendelian genetics, recessive genes should definitely appear as a phenotype (i.e. affect the morphology or look of a shrimp) within three generations in at least 1/4,1/8 or 1/16 of the offspring depending on the number of generations, ect. Based on my interpretation of the definition of pure in the OP, the colony could no longer be called pure if ANY offspring showed up within three generations that were not the intended variant. If such offspring did show up, the count would need to start again. Hence any variant that has a hybrid lineage would take many, many generations to breed pure, if not ever. As suggested in another thread, a better name for these hybrid variants that breed true (or close to 100% true) would be "line bred".  

Hence I read the OP as CRS, CBS, cherry variants and other non-hybrid shrimp are the only shrimp that can ever be considered "pure" which is fair enough. That said, a hybrid variant that produces close to 100% offspring that are the same variant deserves recognition because this takes a lot of work on behalf of the shrimpkeeper - once again I think the term "line bred" is fitting.

 

Share this post


Link to post
Share on other sites
jayc

Top of the class on mendelian genetics.  

The likelihood of the recessive phenotype appearing is reduced after 3 but it's never completely eliminated. 

  • Like 1

Share this post


Link to post
Share on other sites
Baccus

From memory I think they deem 7 generations before a cross bred line becomes pure again. But I suspect that somewhere deep in the genetics there will be some residual of the original cross.

Share this post


Link to post
Share on other sites
fishmosy

Here is a can of worms - I've based my thoughts on Mendelian genetics. What if shrimp genetics dont conform to Mendelian genetics?

Share this post


Link to post
Share on other sites
Jo

I agree that 3 generations isn't enough to determine purity.

However, I also think that the term is of limited use anyway because when buying shrimp you're relying on un-observable information provided by a 3rd party.  

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Similar Content

    • shrimpAquatics
      By shrimpAquatics
      Hey everyone,
      I noticed this the other day on my RCS, a little white grain that was stuck on its head. 
      Does anybody know what this is?
      cheers! 
    • MaNieAk
      By MaNieAk
      Hello all
      I have a small setup ( for now :) , 2 x 60L both with internal filter system
      In one i keep PRL , benibachi x hakata , not the most beautifull ones in the beginning
      but it seems to be getting allot better lately
      The other tank is a ''mixed tank '' containing the following :
      MALE :
      2x Zebra pinto black
      1x crystal white
      2x Ebi Tengi Tangerine Tigers (golden)
      3x Spotted Head Red
      FEMALE:
      1x (shadow)Red Taitibee
      1x PRL SS
      1x PRL SSS
      In this mixed tank i now discovered the following fry / baby shrimp
      Soil is akadama 1-4 mm


       


       


       




       
       
      Can someone help me with naming these hybrids ?
      And what do you think , is it worth it to select these patterns for further breeding ?
      Thanks allot !
       
    • Disciple
      By Disciple
      I have been having some trouble with my water parameters after over dosing on a product a few months ago.
      I have slowly been working on my wp and have finally got them close to where I want them in my tanks, I just need some help to get it even closer to where I want it.
      Tank 1's Wp is ph 6.6 gh6 kh1 Ca40 and the TDS is 170~ Currently the MG:Ca ratio is 2.79 - This is my divided tank holding PRL BB and Pintos
      Tank 2's WP is Ph7.2 gh11 kh3 Ca60 and the TDS is 215~ Currently the MG:Ca ratio is 1.29 - This is my OEBT tank
      Ideally I want tank 1 to be gh5 kh1 and Mg:Ca ratio 3.5 - I was thinking to do this is to add pure RO water to lower the tds some more then add more GH until the ratio is where I want it. My question is there a better way to get this ratio and what do i use to raise gh?
      Ideally I want tank 2 to be gh 7-8 and kh 3-4 with the Mg:Ca around 3.5. This is the tank that  had the most issues and I lost quite a lot of OEBTs at one stage. I think I have got the WP at a stage where they are surviving and breeding again but I would like to get it a little better for them. I just need some help/instruction to get it there properly. 
      I know in both tanks I need to increase the Mg but I dont want the overall Gh to increase or the TDS. I am also not sure the correct product to buy to increase the mg safely. What I have been doing is add RO remineralised with Salty shrimp at a lower tds then what the tank was every water change to slowly bring my tds down. 
      Any advise or guidance will be much appreciated. I think Tank 1 would be ok where it is atm but I would really like to get tank 2 closer to ideal if possible.
      Thanks.
    • Disciple
      By Disciple
      We seem to be having trouble getting past defining or even using pure. The suggestion has been made to use a generational count the same as we use for mischling ie F1 equals first generation you have bred or can confirm true crossing of both parents from the same genetic line and then work up from there. F1 is unstable by F4 should be mostly stable with maybe the odd unusual outcome less than 1% and F5-10 totally true breeding all offspring are the same genetic variant as the parents. so lets see what everyone thinks of this direction give a yes or no response.
      Below is the interesting responses.
      1. Sorry, but does that mean juvies from a BB line that breeds 100% true and juvies from TBMM x TBMM would both be called F1 BB? If so, No. I don't think thats going to help anyone, especially beginners. Sorry if I have interpreted your definition incorrectly.
      2. What if we categorise pure into 2 categories, for those that breed 99% true for the past 2 generations at least, call it Pure. 
      And those that produce high % offspring of one variant (such as: MKK x MKK = 70% true MKK, rest tb,pinto,etc...), we call it line breed (selectively), which means you are selectively breeding one variant to increase % offspring of that variant. And it is necessary to included what are the offsprings from the batch, F number is recommended to included if the breeder is confident with their track record.
      3. the word pure needs to be dropped, as no one can guarantee 100% that they will never produce anything other than the shrimp that looks like the parents and grandparents. I like the notion of F numbers however Mischling origin stock should be clearly labeled versus Cleanly bred stock(does not have Mischling decendants) that are currently breeding true.
       
    • GotCrabs
      By GotCrabs
      Mum bought some plants for her Guppy tank and one of them I'm unsure of what it is, it was sold as Blyxa but I am certain it isn't, it's too upright and some what hard, unlike the soft, lightly bent leaf of a Blyxa, any ideas of what it is anyone? It's growing quite well and I actually don't mind it either.
       




  • Must Read SKF Articles

  • Register today, ask questions and share your shrimp and fish tank experiences with us!

    Join Our Community!

  • Posts

    • jayc
      It must have been an aluminium heatsink. The Indium in Liquid metal will eat through aluminium. Only copper or nickel plated heatsinks can be used with liquid metal. It says so on the packet, at least my pack of Thermal Grizzly Conductonaut does.
    • jayc
    • kms
      I will try to add all the old tank's shrimps at the end of August to the new tank, had a problem with my chiller this morning, try to make it more efficient by adding a better heat sink grease, I added a liquid metal grease, apparently you can't add liquid metal, when heating up, the heat sink turning to dust, along with part of the cooler inlet and outlet. So far the shrimps are ok.    
    • sdlTBfanUK
      I have had the new shrimps a week and have ordered some new ones(10) for delivery friday. There are probably at least 6 of the 8 alive (they may even all be alive still) but as the tank is so densely planted it is difficult to tell, but I saw 2 black and 2 red this morning, as yesterday, but I'm sure 1 red and  1 black weren't the same as the ones I saw yesterday so there are probably at least 6, if that makes any sense??? Anyway that will be it for now and I will just let the tank and shrimps do there thing once this batch are in there in a couple of days, and I can get back to the usual routine as was, before this unfortunate event wiped out the last lot. All parameters are good, including the nitrates now, but there are a lot of brown patches on the plants and moss balls still......... It all looks a bit drab and uninspiring and brown!!! I probably just need to be a bit more patient? I will do some maintenance tomorrow and a small 2L water change, then the new shrimps will go in on friday after acclimatising. The shrimps were totally uninterested in the spinach or shrimp lolly I put in at the weekend but I am assuming they have so much biofilm at this stage that that is keeping them busy and well fed and they are staying under cover until they get used to their new environment and this strange ugly monster that keeps peering in at them through the glass from time to time? I guess if some 100ft tall bloke kept peering through my window a few times a day I would be a bit nervous/reserved shall we say? I removed the spinach and the shrimp lolly and put the shrimp lolly in the betta tank and within minutes there were 10 shrimp on it so there was definitely nothing wrong with that shrimp lolly! Simon
    • jayc
      Traps don't work on hydra. Even with planaria, it is slow and it doesn't catch them all.
×