PROMOTE THE HOBBY THROUGH OPEN MINDED EXCHANGE OF KNOWLEDGE AND IDEAS - Share your experiences as a breeder or novice both good and bad. Pass on your experiences and share results with the next generation. A successful breeder will be remembered for such efforts...

Saturday, December 16, 2023



Why have Speartails dissappeared from the tanks of breeders in North America?  Think it's about time we make a change in that trend...

Multi-Colored Speartail, courtesy of Whitney, L 1952 - All About Guppies

© Alan S. Bias

Permission granted for nonprofit reproduction or duplication of photos and text with proper credit for learning purposes only.
December 16, 2023

For the past two years give or take I've started back working with Speartails.  Something I have not done since a teenager, and that was quite some time ago.  Over 45 years ago to be exact.  Foundation stocks for my current Speartail breedings were obtained from my good friend and fellow breeders Gary Lee of Taipei, Taiwan and Henrik Schneider of Großaltenstädten, Hessen, Germany.

Halfblack Snakeskin Speartail, photo courtesy Gary Lee
Over the last several years, starting with IKGH stocks, through outcross and consistent selection Gary has produced some wonderful results within his Speartail breeding program.  While working with varied genotypes, to date, he has concentrated primarily on showing Halfblack Snakeskin (NiII, SSb/t) phenotypes.  Periodically entering his best fish in IKGH shows and providing his stocks to breeders not only in many parts of Asia, but also Europe and North America.  His breedings and show results can be found and followed at The Guppy Master Project.

Schimmelpennig Platinum Speartail, photo courtesy Henrik Schneider

Henrik has also produced some wonderful results within his Speartail breeding program.  He has concentrated primarily on Schimmelpennig Platinum (Y-Sc) in Blond (b) & Purple Body (Pb) phenotypes.  Also entering his best fish in IKGH shows and providing stocks to breeders in Europe, and now Asia and North America.  His breedings and show results can be found and followed at Hessen Guppys.

At one time Speartails, and other small tail phenotypes, were quite common in North America and around the world.  Reasons for loss of interest and thier demise can only be based on speculation.  In part the rise of Broadtail phenotypes, to include delta and viel, in the 1950-70s played a played a roll in declining interest.

Photo courtesy Madsen 1974 - Aquarium Fishes in Color 
I suspect an often lessor considered culprit came to play for many breeders.  That being a rather complex genotype.  Color and pattern aside, Speartail body and finnage is derived from several combinations of X-link and autosomal genes that are needed to produce desired results in both heterozygous and homozygous conditions.  The latter producing long and thin elongations of the gonopodium referred to as "spirelli" in breeder circles. Resulting in a high cull rate.

Such extensions preclude use of many of the best Speartail males as potential sires without surgical alteration or at best use during a very brief period of time just after the onset of sexual maturity.  Well before mature finnage and other attributes can be thoroughly evaluated.

Speartail is also intrinsic with Opaque (Op) genotype.  Another autosomal incompletely dominant gene which alters angles of crystalline plateletes which reside under the violet-blue iridophore structureal color layer.  Producing "dull and muted" colors, i.e. translucent scale phenotypes.  In homozygous fashion this color inhibition can be quite dramatic, again resulting in a high cull rate.

Lacking a class to exhibit within the International Fancy Guppy Association (IFGA), Speartails are now rarely seen, if not absent, in the tanks of American and Canadian breeders.  Though, they have persisted in the hands of Europian breeders and within the confines of International Kuratorium Guppy High-breeding (IKGH) shows.

In Asia interest in breeding Speartails has seen a steady increase over the last several years.  Though, much of this interest has been commercially driven and not often in the hands of breeders dedicated to producing show quality stocks that adhere to established IKGH standards.  While resulting in many novel Speartail phenotypes, quality is often lacking and many fail to take hold and persist in breeder tanks.

On occasion, "spear-like" phenotypes are seen among breeder results with wild-type Guppies.  Most of these do not stem from defined Speartail breedings.  Rather, they derive from reciprocal Peocilia reticulata x P. r. wingei breedings.  While such individuals can be refined through selection and backcross into true Speartails, most are used in a fashion which continues to produce haphazard results. 

As with all complex phenotypes, selection for Speartails cannot be maintained indefinitaely without periodic outcross from compatible stocks existing within a breeders population or from infusion of unrelated stocks sourced from other breeders.  Attempting to linebred long-term or indiscriminately will result in severely reduced fecundity across all aspects, both visible and unseen.

Speartails, like many unique finnage modifications, require a rigid selection criteria requiring high rate of culling to produce a rather small percentage of desired result.  Upon outcross, initial F1 and F2 offspring will produce a varied result in dorsal and caudal expressions.  Most of which will be culled from a breeding program.  A select few may be used to recombine desired genotype.  

F1 Lowersword x Spear outcross

At the moment I'm working with two specific phenotypes and outcrossings with my various Lowersword phenotypes, as seen in the following photos.  Will see where this journey takes me and if they will continue to hold my long-term interests?  Only time will tell...

Blond Schim Plat Purple Body Spear

Blond Schim Plat Purple Body Spear

F1 Lowersword x Blond Schim Plat Purple Body Spear

F1 Lowersword x Blond Schim Plat Purple Body Spear

Red Snakeskin Saddleback Spear

Red Snakeskin Saddleback Spear

Red Snakeskin Saddleback Spear

Red Snakeskin Saddleback Spear


Find you're spending less time in your fishroom?  Maybe it's time to refocus and reaffirm your goals and interests in breeding.  Show season is just around the corner!


Thursday, March 16, 2023


Working With Vienna Emerald Swords

Do Breeders excessively concentrate their efforts on production of singular phenotypes at the expense of overall genotype?

Grey Vienna Emerald Doublesword male

© Alan S. Bias
Permission granted for nonprofit reproduction or duplication of photos and text with proper credit for learning purposes only.
March 16, 2023

When it comes to breeding Vienna Emerald Swords, I find the biggest issues are often created by the breeders themselves.  Most breeders try to maintain complex strains with far too few breeding’s in too small of a population.   Especially, when compatible breeding schemes are not utilized across multiple phenotypes comprised of similar genotypes.  Such as Blue – Green – Purple in solid or halfblack.  Compatible breeding schemes allow for creation of a much larger “combined breeding population” within an individual fish room or shared among breeders who regularly exchange their stocks.

Several breeding’s made yearly and maintained in a dozen tanks is a requiem for failure when maintaining complex phenotypes in isolation. In my experience a minimum of 40-60 tanks are required to maintain a strain long-term.  Keeping in mind, a breeding strain is not necessarily comprised of a single phenotype.  Rather many phenotypes as a collective group.   At times I run 80-100 tanks of Lowerswords, saving 50-100 drops per year.  A large population allows for needed beneficial mutations to accrue through various genetic principles and mechanisms.  This same concept also allows for identification and culling of deleterious alleles, without need for drastically reducing numbers at any given point in time.

Grey Vienna Emerald Lowersword male

Far too many breeders are focused on linear breeding’s and routinely turning a generation with each breeding result. When your fish are at a point that is satisfactory to you as a breeder it is OK to maintain a "status quo" and utilize the same generation via lateral breeding’s for 2-3 years. Backcrosses can further alleviate the perceived need to turn a generation to improve results.

Think of your breeding program in terms of an isolated wild-type or feral population.  Poecilia reticulata (Guppies) are not like seasonal breeding Salmonid populations.  Healthy Guppy populations are maintained through multiple breeding's throughout the year, and comprised of multiple age groups at any given time.  Why should we as breeders not maintain our domestic breeding programs along a similar parallel as found in healthy wild-type?  I have done so for decades.

In addition to multiple sex-links both X and Y, sum total genotype of "Vienna Emeralds" includes multiple autosomal genes. Both recessive and incompletely dominant.  Autosomal variation, the random nature of recombination among autosomal genes, precludes production of a single "fixed phenotype" in high numbers for extended periods of time.

Mother Nature imposes this principle for a reason.  That being, autosomal genes confer positive benefit only in heterozygous fashion. Attempting to maintain autosomal genes in homozygous fashion long-term confers negative benefit across multiple areas of fecundity within and beyond color-pattern, size and shape. An easy example to visualize is Sickle Cell Disease. The sickle cell anemia gene confers positive benefit to individuals and populations in heterozygous fashion, i.e., immunity from malaria. Yet, in homozygous fashion is lethal.

Grey Purple Body Lowersword male

Another example in Guppies is autosomal incompletely dominant Purple Body (Pb).  Pb mode of inheritance allows for populations to be comprised of three phenotypes:  pbpb - Pbpb - PbPb in a 1:2:1 ratio.  Each construes positive or negative benefit in open or closed canopy environments under a multitude of predation regimes.  In breeder tanks each is used as a "tool" for propagation and maintenance of specific phenotypes.  When Pb selection is narrowed wild-type, feral and domestic populations suffer in the long-term.

Grey Vienna Emerald Doublesword males

These same principles apply to all autosomal genes, if you know where to look. What does this mean as a breeder of autosomal genes?  Rather than seeking to narrow your genotype in quest of a singular phenotype, focus your breeding program on maintenance of multiple autosomal genes, in various states of zygosity, to produce a multitude of phenotypes within your overall breeding scheme.  

In turn, this will strengthen your breeding population as a whole.  Yet, allow for production of a smaller percentage of desired results across multiple phenotypes…

Grey Vienna Emerald Lowersword male


The number of tanks you maintain as a breeder is not the point.  Because it will never be enough.  The point is whether you utilize your available tanks efficiently in quest of your desired result.  Set your goals realistically...


Wednesday, April 29, 2020

Skilled Vision Among Breeders

Historically, the best Pedigree Breeders always have and always will breed by eye. They are visual thinkers.  Such breeders are often very instinctive and gifted with “Skilled Vision.”

Golden Bunt Lowersword

© Alan S. Bias
Permission granted for nonprofit reproduction or duplication of photos and text with proper credit for learning purposes only.
April 29, 2020

Skilled Vision has been loosely defined as a learned practice that allows for recognition and productive results.  Based on powers of observation and acquired knowledge, with far less proficiency in the language of science. 

Successful breeders possess skilled vision to varying degrees, and are able to develop a needed understanding of selection from hands on experience.  Good practice results from recursive breedings made over time followed by evaluation of results.  Incorporating skilled vision and practice in attempt to control selection of genotype, while allowing for positive traits with reproducible results in future generations.  This is the nature of Domestic Pedigree breeding.

Skilled vision can be viewed as a discipline involving multiple sensory inputs.  It has a genetic basis, and is not simply the result of accrued knowledge &/or environmental conditioning (formal education & training).  Yet, skilled vision can be enhanced through breeder communications, exchange of ideas, formal competitions, farm visits, breed standards and scientific knowledge. 

Purple Body (Pb) Lowersword female
Taken as a whole, skilled vision allows a breeder to process and make sense of what is seen day to day.  Breeders often lack expansive terminology to express their accrued knowledge to others.  Rather than relying on anecdotal terminology, the language of science can allow for conciseness in conversation.

Is there a dichotomy between the art of breeding and science?  Yes. While science can help a breeder understand results and clearly communicate them to others, extensive reliance on science in breedings can result in a loss of “balance” in results.  This has been seen in many commercial breeds over the last several decades.

Is there dichotomy between a successful breeder and his lessor peers?  Yes.  Those with skilled vision can take breedings to optimum levels of achievement and maintain them long-term. 

Various Lowersword "Bunt" phenotypes.
Science allows me, as a breeder, to maintain a vast array of phenotypes, with truly little effort, in a related breeding program through understanding of the sum total genotype.  Knowledge of chromatophore interactions that determine color & pattern; what is possible and what is not.

While maintaining a reference collection of nearly 5,000 scientific research papers, this falls short of the visual aids I routinely rely on.  In the form or nearly 70,000 photos of guppies from personal breedings and that of others.   To this you can add another 25,000 microscopy images made over the last 10 years.

My breeding notes are embarrassingly minimal and rarely referenced in day to day practice.  Since childhood, sensory perception and visual analysis of the surrounding environment has always been my preference.  Visual images often convey far more meaning than printed words.  As a result, find little need to convert images to words in my mind.

Observation allows for a balance in results within my breeding program…

Grasseni, Cristina. "Skilled vision. An apprenticeship in breeding aesthetics." Social Anthropology 12.1 (2004): 41-55.

Grasseni, Cristina. "Designer cows: The practice of cattle breeding between skill and standardization." Society & animals 13.1 (2005): 33-50.

Grasseni, Cristina, ed. Skilled visions: Between apprenticeship and standards. Vol. 6. Berghahn Books, 2007.

Grasseni, Cristina. Developing skill, developing vision: practices of locality at the foot of the Alps. Vol. 3. Berghahn Books, 2009.

Tuesday, October 16, 2018

35 Years of Breeding Blond Lowerswords

Download link for complete publication:  English and Mandarin text.

Early Bias Blond (bb) Purple Body (PbPb) Translucent Scale (undescribed)
Lowersword (Y-Ls) circa 1985.

Current Bias Blond (bb) Lowersword (Y-Ls) 2018.

Download link for complete publication:  English and Mandarin text.

Friday, March 31, 2017

Purple Body (Pb) study in Poecilia reticulata, an Autosomal Dominant Gene

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

March 31, 2017

Homozygous Pb/Pb male

(A) Heterozygous male Pb/pb, (B) Non-Pb pb/pb male

The Purple Body gene is located on an autosome. Breeding tests, involving this modification of orange spotting, reveal this trait to have an incompletely dominant mode of inheritance. As such a formal name and nomenclature of Purple Body (Pb) has been suggested (Bias and Squire, 2017a). [Note: Hereafter Purple Gene, or Purple Body Gene used interchangeably in reference.]

Wild Poecilia reticulata, both in native populations and feral introductions, exist in a previously undocumented polymorphic state; Purple Body and non-Purple Body. In Domestic strains both polymorphisms persist as a direct result of intended breeder intervention and as an unintended result of outcrosses between fixed phenotypic strains. The co-existence of the two phenotypes suggests a selective advantage under predation (crypsis) and in sexual selection (conspicuous pattern) under diverse ambient lighting conditions.

A generally accepted definition of polymorphism states: “(1) Polymorphism is the occurrence together in the same habitat of two or more distinct forms of a species in such proportions that the rarest of them cannot be maintained by recurrent mutation. (2) If a genetically controlled form occurs in even a few percent of a population it must have been favored by selection. (3) Polymorphism may either be transient, in which a gene is in process of spreading through a population unopposed, or balanced, in which it is maintained at a fixed level by a balance of selective agencies. (4) Owing to the recurrent nature of mutation, transient polymorphism is generally due to changes in the environment, which make the effects of a previously disadvantageous gene beneficial (Ford 1945).”

The violet-blue chromatophore unit and removal of xanthophores by Pb modification is required to produce an all-purple phenotype. The Purple gene has the ability to modify extent genome-wide chromatophore populations in heterozygous and homozygous condition, with increased visibility in the UV spectrum. As a result, this demonstrates selection favoring short “private” wavelength signaling.

Pb is now identified as the first polymorphic autosomal gene to be described as existent in high frequencies in wild, feral and Domestic Guppy populations. It is capable of pleiotropic effect on all existing color and pattern elements at multiple loci. It should therefore be considered a strong candidate for further studies involving “relationships between spectral and ultra-structure characteristics” in orange ornamentation, and extending to color and/or pattern as a whole as suggested by Kottler (2014). A mechanism is identified by which Pb is capable of balancing overall color and pattern polymorphisms, in turn providing fitness through heterozygosity in diverse complex habitats.

(A) Homozygous Pb (Pb/Pb) modified ornaments, expressing removal of xanthophores and increased violet-blue iridophores. (B) Homozygous Pb (Pb/Pb) modified ornaments, expressing reduced xanthophores and increased violet-blue iridophores. (C-D) non-Pb ornaments (pb/pb) expressing no alteration of xantho-erythrophores.

The following four papers and five supplemental documents are the cumulative result of a 3 1/2 year study by Bias and Squire of the Purple Body (Pb) gene in wild, feral and Domestic strains of Poecilia reticulata. Paper No. 1 - Formal Description, No. 2 - Microscopy Tissue Study, No. 3 - Microscopy Ocular Study, No. 4 - Domestic Phenotype Expression.

Select the "Download Link" tabs below to access screened copies of documents from Cold Spring Harbor Laboratory's bioRXiv preprint server for Biology in .pdf format downloaded to After completion of peer review and publication links will be updated to Poeciliid Research Journal.

1. The Cellular Expression and Genetics of an Established Polymorphism in Poecilia reticulata; “Purple Body, (Pb)” is an Autosomal Dominant Gene (DownloadLink)

S1 TABLE – Condensed Breedings and Results (Download Link)
S2 TABLE – Expanded Breedings and Results (Download Link)
S3 Materials Full Description and Sources (Download Link)

Abstract. Modification of wild-type carotenoid orange and pteridine red coloration and spotting of male ornaments in both wild populations of Poecilia reticulata (Guppies) and modern Domestic Guppy strains by the Purple Body gene has long been overlooked in research articles and little understood in breeder publications. This modification is commonly found in wild-type Poecilia reticulata reticulata populations from numerous collection sites and has been photographed but not recognized in these collections. It is non-existent or near absent in collections taken from variant populations of Poecilia reticulata wingei. We identify and determine the mode of inheritance, cellular and phenotypic expression by the Purple gene in these stocks. The Purple Body color pigment modification is a distinct polymorphism in wild P. reticulata reticulata populations. Its existence suggests multiple benefits that satisfy female sexual selection preferences, and minimize or reduce potential predation risks. Photographic and microscopic evidence demonstrated that Purple Body is a normal polymorphism in wild and domestic guppies modifying color pigment regions. Purple Body is inherited as an autosomal incompletely dominant trait.

2. The Cellular Expression and Genetics of Purple Body (Pb) in Poecilia reticulata, and its Interactions with Asian Blau (Ab) and Blond (bb) under Reflected and Transmitted Light (Download Link)

S1 Materials; Slide Specimen Photos (Download Link)

Abstract. Mature Purple Body and Non-Purple Body male guppies differ from each other in several ways. Non-Purple males may have large numbers of xanthophores, erythrophores, and blue iridophores, in addition to the usual dendritic, corolla and punctate melanophores. Fewer violet iridophores are found. In contrast, homozygous Purple Body males lack collected and clustered xanthophores, although isolated single xanthophores remain. Violet iridophores and blue iridophores (violet-blue chromatophores units) abound. The dendrites of dendritic melanophores are finer and form chains with each other. Punctate and corolla melanophores in areas comprising orange ornaments are greatly reduced in number. The heterozygous Purple Body male has erythrophores similar to those of non-Purple males, but yellow pigment is reduced. The melanophores are not as greatly changed in orange ornaments. In Domestic Guppy strains, and at least in one suspected instance in wild-type, melanophore structure and populations may be further modified by one or more additional autosomal genes.

3. The Cellular Expression and Genetics of Purple Body (Pb) in the Ocular Media of the Guppy Poecilia reticulata (Download Link)

S1 Materials; Slide Specimen Photos (Download Link)

Abstract. Our study revealed the presence of all major classes of chromatophores (melanophores, xanthophores, erythrophores, violet-blue iridophores, xantho-erythrophores) and crystalline platelets in various combinations in the iris and ocular media (cornea, aqueous humor, vitreous humor, outer lens membrane) of Poecilia reticulata. This novel ocular media study of P. reticulata takes into account the distinct interactions of Purple Body (Pb) based on results of previous Bias and Squire Purple Body (Pb) publications. Taken in conjunction with other researcher’s published results (regarding UV reflected color and pattern, vision, mate choice, individual preferences, and opsin capabilities) this indicates that these ocular chromatophore populations together create a complex ocular filter mechanism. This mechanism in turn provides spectral capabilities into the UV and Near-UV wavelengths in both Pb and non-Pb individuals. The chromatophores in the cornea, aqueous humor, covering membranes of the lens, and the vitreous humor comprise an ocular filter system that could reduce UV damage to the internal structures of the eye. The guppy’s ability to use UVA as a visual component provides a “private signally system” that cannot be detected by some predators. While non-Pb guppies should derive benefit in the near-UV from violet-blue iridophore units, greater benefit will be derived by Pb individuals with more violet iridophores functioning in the lower UV and near-UV wavelengths. To our knowledge little has been published for P. reticulata concerning pigmentation within the guppy eye. Macroscopic and microscopic imagery is presented.

4. The Phenotypic Expression of Purple Body (Pb) in Domestic Guppy Strains of Poecilia reticulata (Download Link)

Abstract. Modification of wild-type carotenoid orange and pteridine red coloration and spotting of male ornaments in modern Domestic Guppy Strains (Poecilia reticulata reticulata) by the naturally occurring Purple Body gene (Pb) has been long incorporated into their strains by Pedigree Stock Breeders. It is inherited as an autosomal incompletely dominant trait. Its existence has allowed breeders to produce a vast array of Purple based phenotypes. Photographic evidence demonstrates that Purple Body is a normal polymorphism in domestic guppies modifying color pigmented regions. When combined with currently used mutant genes such as Albino, Blond, Golden, Asian Blau, Coral Red, Magenta, Grass, Moscow, Pink, Platinum, Red Mosaic, Multicolor, and Full Red, startling new phenotypes are created. The recently described Purple Body gene (Bias and Squire 2017a, 2017b, and 2017c) has long been overlooked in research articles and little understood in breeder publications.

IFGA Purple Delta, photo courtesy of Terry Aley

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Click on blog photos to enlarge