Génétique Rhacodactylus cilliatus,questions:

Bonjour a tous,est ce quelqu'uns pourrait me conseiller un lien ou eclairer ma lanterne a propos de la génétique des rhacodactylus cilliatus?
Je vois qu'il y'a beaucoup de phases en captivités,est ce que ce sont des gènes recessifs?ou alors simplement un polymorphisme de l'espece?Si j'accouple 2 rhacodactylus "flame" aurais-je uniquement des jeunes de cette phase ou il peut y avoir un pannel élevé de colorations,dans ce cas les phases ne seraient pas définies par rapport a des genes mais plutot des criteres?
Si quelqu'un peut répondre a mes multiples questions!
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Simon

http://www.manitobaherp.com/forums/archive/index.php?t-448.html

Merci thor,sa répond en partie a mes questions,y'a eu des études scientifiques publiées la dessus?Donc comme je le pensait la genetique des rhacos est assez compliquée,apparement pas mal de polymorphisme aussi!Je compte en acquérir bientot donc je me renseigne un peu,on voit beaucoup de rhacos phasés chez les gens ,pas beaucoup de normaux,voila un peu le pourquoi de mes questions^^
Si vous avez encore des informations sur la genetique des rhacos je suis preneur!
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simon

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Home > Care > The Captive Care & Reproduction of the Crested Gecko (Rhacodactylus ciliatus)



MORPHS
The Crested Gecko's polymorphic nature, and the possibility that the species is temperature sex dependent (incubation temperature determines sex) make it an excellent candidate for breeding by the advanced hobbyist as well as research biologist. We will focus here on the advanced hobbyist, and what could possibly be challenging to him/her with such an easy to keep species.

Its all in the Genes! The Crested Gecko's natural tendency to produce offspring with highly variable colours and patterns is quite unique. If you have been in the hobby even a short period of time, you will no doubt be familiar with the many colour and pattern varieties of Leopard Geckos that are now sold in the trade.

Lets look at your average group of wild caught Leopard Geckos. If you took a sample of a thousand wild caught leopard geckos from a single location, you would notice that nearly all of them have similar and fairly drab colouration. If you take a similar sample of Crested Geckos, you will find an incredible variation in colour, pattern, and even shape. Natural Leopard Geckos look very little like the "Designer" Leopard Gecko that we see in today's hobby. It has taken many years of selective breeding to produce today's "high end" Leopard gecko. And many its popular variations are based on mutations, not variations. The Albino, Blizzard, and Leucistic traits are all genetic mutations, and not "natural" variations.

These mutations are produced by a combination of recessive genes that by the luck of the draw, are paired up to produce something new. These genetic mutations, are very rare, and a high dollar value is placed on them when they are introduced into the hobby. This value often reflects only the rarity of such mutations, and is usually not a reflection of beauty.
How many of you actually think a "blizzard lizard" is a beautiful gecko? It is (was) a rare mutation, which like the leucistic, and Albino, captured the hearts (and pocketbook) of many a collector.

Variations on the other hand, are more "natural" traits that, when selected for, can be developed and brought from a nearly insignificant hint of colour or pattern, to a prominent feature through generations of selective breeding. "High Yellow", and "Tangerine" are good examples of Leopard Gecko variations, and the "Sandfire®" bearded dragon is another example of line-bred traits.

Line breeding for both mutations and variations, are a challenging project for the advanced hobbyist, and are a good lesson in genetics. Care must be taken when selectively breeding for traits. Some traits are linked with others, and can produce deformities. Inbreeding can also often result in the appearance of health threatening mutations, and consistent out-breeding is necessary to introduce new genetics and insure the strength of future generations
Where am I going with all this, you might ask. What I am getting at, is that the Crested Gecko, in only a few generations, has shown us many interesting and beautiful variations. And early breeding results show that the offspring show an extremely high "response" to selective breeding.
On the other hand, genetic mutations (as described above) in Crested Geckos are yet to appear, and are a pure representative of "Lottery" like odds that will eventually appear as more numbers are reproduced in captivity.

While hatching out an albino specimen can be exciting, it is not the reward that is the result of challenging selective breeding that takes generations to produce. The Crested Gecko is a breeder's "lump of clay", and the opportunity to select and create "signature" geckos has never before been such an opportunity. Think of looking at a plain old Carp, and knowing that with hard work and a little luck, a Show Koi is just around the corner.

There are several interesting characteristics in the Crested Gecko that will lend themselves well to selective breeding. Base colour and pattern seem to be independent from each other at this point, but could prove to have specific links with future study. I will try in the following paragraphs, to define many of the traits that have been identified and selected for at this point, also attempt to remove some of the confusion in all of the different words breeders have been using to describe them, and attempt to simplify it by combining many of these names.

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COLOUR MORPHS
I will try and categorize the common colours the best I can. This is not an easy task because of a Crested Gecko's ability to change colours in an almost chameleon-like way. Each of these colours can appear in a unicolour morph, or bicolour morph, and can also be combined with a variety of patterns that will be described here.
The Brown Group:

Buckskin - A colour that is various shades of brown, yellow/brown, or tan. Many call this the "normal" phase because it is the prominent colour in nature. Buckskin paints a pretty good picture in most minds, and seems to be the popular description for these unspectacular specimens. These geckos can change from light to dark as influenced by their surroundings. Photo 1

Olive - This morph can vary from very dark to almost pastel, and to the untrained eye, could sometimes be described as green. The colour we know as olive in painting, is actually a combination of yellow and black, but contains no blue pigment as a true green (green is a combination of yellow and blue). That green tint you see in many other colour morphs seems to be this olive colour

Chocolate - These geckos are distinctly darker than the buckskin, and can appear almost black at times. They appear dark most of the time and do not seem to change colour as much as the buckskin variety.

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The Red Group:

Salmon - The salmon phase (often called peach and red) is a beautiful morph that is one of the more difficult colours to isolate. These geckos can appear absolutely stunning at times, but at others can become quite drab. There seems to be a lot of olive pigment in these specimens still, and only future breeding efforts will "clean up" and improve this trait.

Orange - This phase is distinct from the salmon phase. It has much more yellow pigment, and is usually brighter in general than the salmon. It tends to hold its colour better, and as it changes, leans in the direction of the sulfer phase rather than the buckskin, as does the salmon.

Red - The "true red" colouration is an intense colour that has evolved from selective breeding, and is quite an attractive morph. It tends to hold its colour better than the Salmon, but can still change from an almost pastel to a bright "blood red". Most of the red Crested Geckos fall into the Salmon or Orange category if looked at closely. All three of these varieties can be equally impressive, and attractive to the collector.

Rust - As the name describes, this dark phase appears as a mix of the orange and chocolate phase, and has been referred to as "burnt orange" occasionally by breeders. They can appear very dark and almost chocolate like at times, but they always have that hint of orange that makes them distinct. They can also, at times, appear quite light, but always obtain that hint of chocolate.


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The Yellow Group:

Yellow - These geckos appear quite bright in colour, and rarely become dark and drab. They have very little brown or red pigment. They can be quite light at times, and are sometimes mistakenly identified as "pastel." (With the high amount of colour changing ability, it is difficult to call any morphs of the crested gecko pastel).

Sulfur - This morph is what I would call a combination of yellow and rust. These geckos can be quite bright at times, and appear nearly orange in colour. They never get as dark as a rust, and can often be difficult to differentiate from the orange morph.

Cream - This spectacular colour is actually non-existent in a unicolour morph at this time, but in only a few generations will probably develop. This cream is the same bright creamy white that is part of the "fire" and "pinstripe" morphs. Selective breeding has shown this trait to show up more and more with each generation. This is an example of what can be created in the future.


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The Patterns:

The Brindle - Brindle is a term commonly used in mammals to describe a faint tiger stripe/marble pattern, and when we look at Crested Geckos today, this term is more appropriate. Maybe in the future we will see true tiger striping on a Crested Gecko, but for now, the term "brindle" seems the most descriptive and accurate. This pattern is typically most prominent in the flanks, but can be present in the legs and across the lateral rows of crests on top of the body.

The Dalmatian: This is exactly what it sounds like, a small black spots that can appear anywhere on the body. It would probably be more appropriate at this point to call them "pepper" phase, because we do not yet have a gecko that has as much black as a Dalmatian. But that time will soon come, and eventually, it will be possible to produce a solid black gecko from this small trait.

The Fire: This exciting pattern gives one the impression that the gecko has flickering flames on its back. It is usually prominent between the lateral rows on the geckos back, but now it is showing up on the feet and flank as well. The term fire is not descriptive of the actual colour it contains, (a bright creamy white), but rather a unique random placement of this colour that gives the appearance of a flickering flame. Many geckos also have this same colour covering the top of the whole tail, but the colour on the tail seems to be independent of the fire trait.

The Pinstripe: Also called "painted thigh" when present on the fringe of the hind legs, this is the same creamy white that is present on the Fire morph, this trait is independent of the fire trait, and the colour is found in association with the enlarge scales along the sides of the body that make up the lateral rows, the fringes of the limbs, and even the scales around the mouth.
The Bicolour: This morph is a combination of usually light and dark colours, where the light colour is restricted between the lateral crests, and the flanks are usually a dark colour that can contain some brindle patterning.

The Harlequin: This is another trait name that has been imported from the mammal world, and it is a popular and good description for Crested Geckos. It is a combination of light and dark colour morphs, that appear in a variety of blotches and patterns. Typically, the mid dorsal area (between the lateral crests) is primarily light in colour, and the sides are dark and patterned. This is independent of the fire morph, but they are commonly found in combination.

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I have made an attempt to describe the most common varieties here, and tried to set some kind of a standard, so that we are all on the same page when discussing these traits. These are my opinions only, but I have tried to take all that is out there and simplify it for future discussions. Some will disagree, but hopefully most will find these descriptions useful, and adopt them in discussion, of Crested Gecko morphs. We can, there by, eliminate confusion, and be on the same page.

Other Morphs: There are several physical traits such as head size, and crest size that will undoubtedly come into play in the future, and I am sure that I have forgotten some here.

The point is that the "Sky is the Limit" when you think about the possible combinations of all these different traits that can challenge the selective breeder, and make your gecko an individual standout. Working with Crested Geckos can provide a keeper with an interesting and unique challenge, and be the platform for learning about genetics, business, and planning."



http://www.geckoworld.net/care_r.ciliatus.htm

Nickel,c'est exactement ce que je voulais savoir,en fait la genetique des geckos c'est comme les carpes Koï(d'ailleur le type en parle),c'est en partie de la chance.Je voudrais commencer avec des spécimens qui n'ont pas vraiment de mutation,je trouve plus interessant de commencer avec des spécimens naturels,et si en plus on peut obtenir des couleurs différentes avec des sujets normaux sa doit etre assez sympa!
Faudrais que j'ouvre un topic ou les gens mettraient les différentes variations qu'ils ont obtenu en repro,et les parents etc...Sa pourrait etre interessant,qu'en pensez vous?
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Simon

Pourquoi pas,mais réfléchis bien avant,que ça ne soit pas une incitation pour plein d'apprentis-Frankenstein des phases...

Ouai je vais y reflechir.Toi thor,tu as des rhaco,ce sont des normaux me semble t'il?T'as deja eu des jeunes?Si oui etaient ils tous normaux?
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SImon

Non,le mâle est normal,par contre l'une des femelles est chocolat foncé avec des points noirs ("dalmatian") et l'autre orange "flame" bien pétante...au passage on n'est pas sur MSN,gardons les pseudos merci
Pour les petiots ils sont tous nés marron-rouge très riche,et les petits de la femelle orange avaient la tête et l'espace entre les deux crêtes du dos bien orange avec le temps.

Excuse moi,je ne pensais pas que tu voulais passer incognito sur ton forum,désolé,c'est rectifié

Non c'est pas la question,c'est pour ma...tranquilité

... avec tout ça on pourrait se demander s'il est vraiment raisonnable de vendre un R. ciliatus avec un morph "spécial" 2X plus cher qu'un morph "normal" (parce qu'en somme chez cette espèce tous les morphs actuels sont normaux/naturels)...

La réelle "innovation" chez cette espèce serait l'apparition d'une mutation, induisant un albinisme, leucistisme ou mélanisme...

tout a fais d accord Pouf a partir du moment ou les probabilités sont les memes je penses que certains eleveurs le savent tres bien mais jouent la dessus pour vendre plus cher ce qui n est pas tres honnete c est une logique de marché comme on en vois pour des mutations rares chez d autres especes mais qui ne tiens pas compte de la rareté

C'est aussi a cela que je pensais en posant la question,il semble tout de meme que le fait d'avoir des geniteurs ayant certains criteres favorisent l'apparition de ces criteres sur les jeunes,cela pourrait eventuellement justifier le prix,souvent quand on prend un reptile par rapport a sa genetique c'est dans un but de repro,on peut voir les rhaco uniquement pour leur beauté sans penser a la projeniture!C'est le cas pour les carpes koï aussi,y'en a qui coutent des fortunes,mais ce n'est pas parce qu'elles coutent des fortunes qu'elles rapporteront une fortune a l'avenir,puisque les couleurs qu'auront les jeunes sont assez hazardeuses!Le pire avec les carpes c'est qu'au fil de la croissance les couleurs evoluent,j'avais acheter des magnifiques carpes koi argentées,elles sont desormais adultes et elles sont oranges et blanches,comme quoi!
Je ne sais pas si j'ai été clair mais en gros,je pense que si on paye un rhaco cher c'est pour lui meme et non pas ce qu'il peut donner,apparement le ratio de spécimen joliment colorés est relativement faible,ce qui pourrait expliquer le prix plus élevé,c'est le cas chez les carpes aussi,le couple adulte peut etre hyper moche mais donner une descendance qui vaudrait plusieurs milliers d'euros!
C'est encore la meme chose pour les poissons rouges,un pote en avait 2 rouges dans le bassin ,ils se sont reproduits et y'a eu des blancs,des noirs,des rouges et blancs,rouges,oranges!
Je trouve que c'est plus sympa avec ce genre de phases qu'avec celles des gutt par exemple,on ne peut pas prévoir ce qui va sortir ,comme a la lotterie,tandis qu'avec les gutt et co,on sait déjà et si on veut voir apparaitre quelque chose d'inedit ,il faut y mettre 10000 euros et 10ans de patience!
C'est pour cela que je pense que je vais me mettre au rhacos avec des specimens se rapprochant de la couleur naturelle!C'est plus marrant!