Why A Mirror Carp?

[Newt]

Sorry Budgie but unless they have recently discovered new info, it can't quite work like that. Using the standard lettering for the genes in carp that have to do with scales (and a few other, less clear traits), and given that this is a case of incomplete dominance so that each allele (S, s, N, n) influences but does not absolutely control

 

S = strong push toward scaly

s = weaker push toward scaly

N = strong push toward nude (against scaly)

n - weak push toward nude

 

SSnn common

Ssnn common

ssnn mirror

ssNn leather

SsNn linear

SSNn linear

SSNN dies

SsNN dies

 

Any N allele results in leather, linear, or dead. Mix and match how you want but if all the fish in a pond carry the N allele, you will not get any commons or mirrors (although some of the linears may look like mirrors)

ssNN dies

[peter mccue]

Very interesting post Newt, just wish to hell I could understand it!

 

Just as a matter of interest mirror scaling occurs in most of the cyprinids, there's a photo in 'The history of Carp fishing' which shows a Rudd with mirror scaling, now that has to be a handsome devil.

 

I think the mirror scale mutation is called the Mendellian factor.

[poledark]

Always been my understanding that the mirror/leather varieties were simply selected and bred from because less scales made preparing them for the table easier. They were of course bred on the continent.

 

The old english carp were all common scaled, and a couple of fish farmers/importers (Don Leney) imported the mirror/leather varieties and sold them to estate owners to eat the weed in their lakes. That last statement was straight from the horses mouth, Don Leney told me that himself.

 

Left to their own devises the mirror/leathers offspring will revert to the common scaling in a few generations, as per Redmire pool.

 

Den

[Newt]

Sorry Peter. I never know when that sort of post is clear to people and when it is not and on re-reading, I posted some false info.

 

- Short version - a parent can only pass along genes it has.

- Paired genes (humans and carp both are built this way) give you one pair from each parent.

- Since both commons (fully scaled) and mirrors only have n, their offspring will only have nn.

- nn offspring will be either commons or mirrors.

 

As an added note, since NN is fatal, about 1/4 of the eggs from leathers and linears will die from genetic problems and about 1/4 of the eggs will become commons or mirrors.

 

Commons & mirrors cannot produce leather or linear offspring.

 

Leathers and linears can produce common or mirror offspring which is not what I wrote in #11. Sorry for that goof as well as the earlier one that Budgie caught.

 

That explanation is probably as clear as mud too but at least I think it is accurate.

[poledark]

Surely a "leather" is simply a "mirror" with fewer scales....I have never seen a pure leather, they always seem to have at least a tiny "imperfection" somewhere.

 

Back in the dark days me and a mate used to "shift" fish from one part of the country to another, and we always selected the nearest to leathers we could.....Don Leney topld us they had more potential for growth as they did not waste energy in producing scales

 

Den

[Newt]

Den - since the genes that control scale vs no scale in carp are not absolute, it is very possible that a genetic leather carp could have an odd scale or three.

 

S - selects strongly toward scales

s - selects less strongly toward scales

N - selects strongly toward nude

n - selects less strongly toward nude

 

SS will almost certainly be heavily scaled

Ss will be less so

ss will be even less so

 

NN will be dead

Nn will lean somewhat heavily toward nude

nn will lean less heavily toward nude

 

It requires expensive genetic testing to know if you are dealing with a leather carp with a scale or two or a mirror with only a scale or two and I'm not sure the difference is even worth knowing for an angler.

[Newt]

Posted on behalf of Tracy. Please add all replies to this thread:

 

Elton - have you heard anything back from Tracy? It's hard to tell if the info given here is what he/she was after.

[Dick Dastardly]

Surely a "leather" is simply a "mirror" with fewer scales....I have never seen a pure leather, they always seem to have at least a tiny "imperfection" somewhere.

 

Back in the dark days me and a mate used to "shift" fish from one part of the country to another, and we always selected the nearest to leathers we could.....Don Leney topld us they had more potential for growth as they did not waste energy in producing scales

 

Den

 

 

Exactly Den!

 

Ive also heard the same about leathers as well but never from a scientific point though.Im fairly sure it must just be a "bivvy legend".

 

I think the main reason that Mirrors and Leathers tend to be the biggest is once again down to the origonal selective breeding of the "KIng Carp" strains for the table.

[Vagabond]

Any N allele results in leather, linear, or dead.

 

 

That's true enough Newt, but its more complicated than that.

 

if Nn breeds with Nn then you get offspring that is

 

25% NN(dead)

50% Nn and nN (mirrors or linears)

25% nn (which will be susceptible to reverting to commons if the other pair of alleles contains SS)

 

That is why a population of mirrors will gradually revert to common - death selects against the N gene when its doubled.

 

(Although even the above is a simplification and ignores random mutations)

 

What I am interested in is the various strains of carp and their origins.

 

eg, the classic "Galician"

the humpbacked "Aischgrund" strain

the long heavy "Dinklesbeule"

most of the carp that people catch are either the pot-bellied monstrosities of the AT front page, or else some sort of mongrel strain with bright yellow undercarriage and tail

 

Is there anything fairly erudite on that subject?

Edited June 27, 2007 by Vagabond

[Dick Dastardly]

Sorry Peter. I never know when that sort of post is clear to people and when it is not and on re-reading, I posted some false info.

 

No worries Newt you realised the mistake before I could take you to task!

 

Genetic coding is a confussing subject and as such one that I thought best just mentioned but not going into exact detail! As with a lot of stuff fish/fishing/fishery management related Ive studied/been taught I often find practical on the bank experiences/observations are the far simpler way to explain.More people can relate to these examples.