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Tuesday, May 7, 2013

The IFGA Gold Body Class ...A Phenotype in Need of Genetic Clarification

The IFGA Gold Body Class   ...A Phenotype in Need of Genetic Clarification

© Alan S. Bias
Permission granted for nonprofit reproduction or duplication of photos and text with proper credit for learning purposes only.

Normally IFGA phenotypic classification of color and pattern does a pretty good job based on its primary intent.  A means to avoid confrontation during a show based on divergent interpretations of genetics while judging.  It is a way to separate genotype from phenotype and simply view things for how they appear at a particular moment.  A visual "snapshot in time" if you wish.  Inconsistent lighting issues at shows aside, in most cases this system works as well as any found in similar livestock judging venues, allowing for amicable results.  But not always.  Case in point the IFGA Gold Body Class.

1.  IFGA AOC color class is defined as any color not covered by another recognized show class as determined by body or caudal color.
2.  IFGA Gold color class is defined by basic body color with no regard to "color pigment" in either body or caudal. It is comprised of fish that are homozygous double recessive for  Blond (bb) and Metal (Mg).  In many instances they are also triple recessive for Purple Body Mutation (Pb).  

IFGA Gold Body Color Class Male w/Pb (Courtesy Bryan Chin and  RMGA) 
The following excerpts show current IFGA classifications for male Guppies as taken from the most recent Judging Booklet:

Photo text courtesy of  International Fancy Guppy Association (IFGA)
Photo text courtesy of  International Fancy Guppy Association (IFGA)

Requirements for "IFGA Gold" as a body class are simply stated as:  "A Minimum of 25% of a yellow gold color in the body".  In the Classification for Show Entries chart IFGA Gold breaks out after 1.  Swordtails, 2. Albinos and 3-4. Body Patterns for HalfBlack (HB) and Snakeskin (SSB).  It is followed by Caudal Color.  A further note indicates:  "Bronze and gold-bodied fish will be classified by the appropriate body color.  These body colors referring to autosomal recessives Golden (gg) - IFGA Bronze and Blond (bb) + Metal (Mg) - IFGA Gold.   Under Color Clarifications it is further stated: "Gold:  Will be defined by basic body color (25% yellow gold color)".  This "yellow gold color" in essence results from a metal overlay on a blond fish.

What follows is an excerpt from "Judging Guppies" by Stan Shubel under the section pertaining to Body Color.  As incorporated into to the IFGA Judging Booklet for the judging of Male Guppies.
Photo Text courtesy of  International Fancy Guppy Association (IFGA)

Genetically, I interpret this to mean not all homozygyous Blond (bb) fish will meet the requirements for IFGA Gold Color Class.  As they do not incorporate a 2nd autosomal recessive for Metal (Mg) in homozygous form.  Many such fish, while possibly heterozygous for Mg lack homozygous metal expression and are not considered "IFGA Gold".   Many authors in the past have simply stated, "The IFGA refers to blond as gold".  This is not necessarily true.  The IFGA does not recognize, or at least actively promote, the term "blond" as it is a "published genotype".   This has created a large void in phenotypical descriptors in North America.  It may be a better conclusion to state: "The IFGA has no terminology for blond".  As such Blond fish in the IFGA lacking Mg are normally shown by tail color classes (in theory with corresponding matching body color pigment) or in the AOC or Pastel classes when they fail to meet cutoffs in other class requirements.   AOC classed fish are more likely to be simple Blonds with or without Pb, and lacking solid colored finnage for entry into Red, Green, Blue, Black, Yellow, Pastel or Purple caudal color classes.  Blond males lacking Half-Black simply default to a color class based on caudal color.

IFGA AOC Color Class Male w/Pb (Courtesy Bryan Chin and  RMGA)

IFGA AOC Color Class Male w/PB (Courtesy Bryan Chin and  RMGA)
Each of the two above examples are basically homozygous Blond (bb) fish with at a minimum additional autosomes for Purple Body Mutation (Pb) and Zebrinus (Ze).  What each visibly lacks in genotype is autosomal Metal (Mg) in homozygous form needed to be phenotypically classed as IFGA Gold.  It is likely these males are part of a strain bred for competition in the IFGA Gold class.  In other parts of the world such fish would be referred to both by genotype and phenotype as blond.  In North America by those outside IFGA circles as blond both by genotype and phenotype.  As the IFGA has neither terminology or classes for "Blond" fish they are considered AOC's.

IFGA Gold Body Color Class Female w/HB (Courtesy Bryan Chin and  RMGA) 

The following excerpts show current IFGA classifications for female Guppies as taken from the most recent Judging Booklet:
Photo text courtesy of  International Fancy Guppy Association (IFGA)

Photo text courtesy of  International Fancy Guppy Association (IFGA)
IFGA Gold females often express X-linked Half-Black (NiII) and are allowable in the Gold Female Color class.  While their sibling males are more likely entered in the Yellow or AOC Color classes.  Again, it must be remembered the IFGA color classes are determined solely by phenotype and not genotype.  As a result Half-Black (NiII) is "visibly recognized" only in grey bodied fish based on phenotypical expression.  It should be conceded that blond fish do visibly express a "weakened" version of NiII.  For comparison, in the following photo is presented a grey bodied female w/Mg.  While expressing "Gold Pigment" in finnage, she lacks both blond and NiII to enhance expression in body.

Grey Mg Vienna LS female (Bred by Alan S. Bias)
Discussion:  Body color and pattern in guppies is controlled by regulation within segmented regions in both body and finnage.   Often in "combination" from both sex-link and autosomal traits or in "complex"  from linked gene(s).  Additionally regulation is often distinct in body and finnage under separate controlling mechanisms.  Metal is regularly expressed in:  1.  Body, 2.  Body and finnage, or 3. Just finnage.  The two following blond IFGA delta males visibly express Mg in the caudal, but appear to lack it in the body.   IFGA Gold  only takes into consideration "body color" and not in finnage.   While blond, as a result of lacking Mg in the body they can only be classed as AOC or Pastel.  

IFGA AOC Pastel Males (Courtesy Bryan Chin and  RMGA)
Metal is present in many guppgies, including IFGA strains, not classified as IFGA Gold.  The "yellow sheen" visible in IFGA Apple Green Delta are a direct result of Mg.   Mg can be found in both grey and blond bodied fish.  It is found in several different segmented regions as "standalone" patches, overlaying color pigment or as part of larger regions such as the shoulders in Schimmelpennig Platinums.  Metal is expressed in the following grey bodied Green Male in both the peduncle and at the juncture of the caudal base.  It is also evident in the shoulder if you look closely.
IFGA Green Delta (Courtesy Bryan Chin and  RMGA)
Initial misconceptions about the IFGA Gold class may have resulted from limited visual representation.  When contemplated in the 1960's it is doubtful a true representative photo would have been possible by anyone less than a professional photographer.  Only within the last decade or two have photographers begun to capture the true essence of an IFGA Gold as something much more complex than a simple blond guppy.
Photo text courtesy of  International Fancy Guppy Association (IFGA)
While specific to IFGA Bronze, the above criteria is also reflective of IFGA Gold.  No consideration in "pointing" is given within IFGA standards for additional "color pigment" in the body or finnage.  This is further compounded by a "Bias" of Judges towards color pigment in IFGA Golds, especially in the form of yellow.  In most instances iridophore differentiation is readily distinguished from yellow color pigment.  Reflective qualities are the result of guanine or purine crystals, and not flat color pigment.  So many IFGA Gold's are disqualified for additional yellow pigment it is nearly shunned by breeders.  Improvements upon the "Golimowski Type" IFGA Gold with pastel / white finnage have been nearly non-existent, resulting in a stagnation of the color class.

Blond Lower Sword w/Mg (bred by Alan S. Bias)
In the above example are two sibling males.  The upper is a Grey Lower Sword w/Mg and yellow pigment.  The lower is a Blond Lower Sword w/Mg and yellow pigment.  The latter would meet IFGA criteria for IFGA Gold class if he possessed a delta tail.  I photographed these two males with deflected flash after a period of nearly two hours in total darkness, sometime after midnight.  The purpose was two fold;  1.  First to show motility of yellow color pigment, in that the fish are able to "turn it off", 2.  Second to show that yellow metal iridophores are not (or at least very minimally) reactive to reduced light and motility.

Attempts by breeders, such as Luke Roebuck and others, to show "improved" delta strains within the IFGA Gold class have, to date, met with resistance.  While I visualize and breed my guppies based on phenotype, for understanding I often interpret results as an expression of genotype.  Unfortunately, this is in direct contradiction to IFGA phenotypical judging.  Breeder successes in improved "Golds" resulting from combinations of Metal (Mg) + Asian Blau (Ab) + Blond (bb) can result in near full body expression.  This form of amplification of expression via combination is similar to Asian bred Full Platinum's that result from Metal (Mg) + Half-Black (NiII) + Blond (bb) .  Yet, in combination with yellow pigment such fish are only regularly "downgraded" to Yellow Delta classes when not disqualified.  Despite IFGA Gold body color being determined prior to (Yellow) Caudal Color on IFGA classification charts.  There continues to be a lack of willingness to accept "Full Golds" on equal terms to traditional IFGA Golds with patches of metal and translucent regions of color.   All that is required is a minimum of 25% gold body color, in the form of Metal (Mg) in combination with Blond (bb) with or without Purple Body Mutation (Pb).
Asian Blau Schimmelpennig Platinum (bred by Alan S. Bias)

Herman Magoshitz Full Yellow w/Mg (photo courtesy Luke Roebuck)

Summary:  During the past 15 years I have primarily concentrated my breeding's heavily on both gold  iridophore pigment and yellow color pigment in Lower and Double Swords.  Both in grey and blond body fish.   I have found each to be extremely "moody" in nature.  The yellow color pigment by direct influence of the mood of fish as individuals or stress related events, and the gold iridophore pigment by autosomal influence.  Otherwise, the latter is fairly static.  Over the last three years I have additionally focused on the addition of Asian Blau (Ab) to this equation.  In general, in the mornings my entire fishroom can appear as tank after tank of white finned fish with gold striping in the fins and body.  By early afternoon in natural or handheld incandescent lighting it is just the opposite.  Tank after tank of yellow finned fish.  The following photographs exemplify the effects of metal in both grey and blond fish.  Some of which would meet criteria for IFGA Gold if in delta form.

Grey Vienna w/Mg (bred by Alan S. Bias)
Asian Blau Grey Vienna w/Mg (bred by Alan S. Bias)
Blond Vienna w/Mg (bred by Alan S. Bias)
Asian Blau Blond Vienna w/Mg (bred by Alan S. Bias)
Grey Vienna Pb w/Mg (bred by Alan S. Bias)
Asian Blau Grey Vienna Pb w/Mg (bred by Alan S. Bias)
Blond Vienna Pb w/Mg (bred by Alan S. Bias)
Asian Blau Blond Vienna Pb w/Mg (bred by Alan S. Bias)


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  1. This was a very good read. I am one who knows basically nothing concerning guppy genetics, but I want to learn. There isn't many places to find information that is this thorough, yet easy to follow. Thanks!

  2. also thanks from germany... nice to know that similar problems between judgement/standard classes and pheno/genotypecical traits are also known from IFGA.
    We have got "blond" as competion class in our IHS but we have got problems to devide or summarise cover pattern/colors in some cases.
    For example "pink" als competion-color-class for only "pingu" ( Ni² with basecolor pink)...but Moscow Pinks (Pandas) are genetically also pink, but will be named and judged as greys.

  3. great read, thanks Alan. judging from the declining number of contest entries in Poland it seems the whole system needs a big refresh. I can assume it's no different around the world.

    reading the Russian works - and looking at my fish after that - I can easily recognize more than 5 base body colours. the blonds may be more yellow or white, the greys come in different types, too.
    albino and bronze are a different story. you may have a gold (blond) albino or a grey one - easy to check by outcross to a blond fish - the F1 will be blond or grey. same with bronze. from genetic standpoint the two are not base body colours. but contests are not done by geneticists...

  4. Greg - Yes. Many breeders fail to recognize differences in phenotypic expression of double recessives. There is often a noticeable difference in expression between "blond albino" and "grey albino" within the same strain. Same for "blond / bronze" and "grey / bronze". Very noticeable in melanophore collection, reduction or amplification. A triple recessive for albino / bronze / blond is much different from it double recessive albino / bronze / grey counterpart. Tks for reading. ~asb.