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Has anyone ever seen blue rough green snakes alive? Recently I read an article in the DATZ (German Herpetological and Aquacultural Magazine) from 1996 and saw a nice pic of a blue Opheodrys aestivus. Is this a variant typically seen or is it a rather unique feature?
Regards,

Mathias

Many "green" herps have pigments that interact with UV and are actually Blue without exposure to sunlight, Like getting a tan. Waterdragons, Whites tree frogs, and probably rough green snakes are a few examples. The effect is most commonly seen with captive bred animals that have not had the same exposure to natural sunlight. Many dealer/breeders sell "blue" variants of these animals and some are genetically blue'er then others.. just as long as you keep them out of the sun. Since very few/none breed rough green snakes blue variants are rare only because captive bred are rare.

Hmmm...that´s new to me. As far as I know, blue colour in reptiles is a structural colour produced by interference on melanin layers in the iridiophores. Green should therefor be produced for the human eye by overlaying that blue colour by a rich layer of yellow pigment derived from some carotinoid derivates such as one of xanthins. Mixing these two colours should produce green. Lack of xanthin in green species such as Morelia viridis should produce blue colour, lack of black pigment should produce yellow specimen. The amelanistic M. viridis is indeed yellow. I´ve seen blue M. viridis females during gravidity which turned to green after having successfully laid and incubated eggs. Therefor I assume the hormonal situation of these animals must have had direct influence on the expremation or distribution of the yellow pigmentation. That there is a considerable amount of yellow pigment in M. viridis. You can see that in freshly preserved specimen, where the yellow pigment is washed out by the ethanol used for presevation. You can see it at a yellow sediment after some days and the befor green snake has turned to blue.
After having said this I assume, that the blue rough green snake is rather a mutation, i.e. an axanthic specimen than a mere UV light shortage variation. Moreover...shouldn´t all green reptiles become blue in captivity, if your theory is true, that should be the case, right?
Best regards,
Mathias

My understanding is that xanthin increase with exposure to sunlight and decreases in its absence. just as melonin does when you get a tan. I am not saying that there aren't genetic axanthic morphs that are blue, but that in some species of green herps it is easy to produce a "blue" specimen, by reducing exposure to sunlight or reducing carotene in the diet. Its not a theory, it has been, and can be demonstrated in waterdragons and whites tree frogs for example, were most captive bred babies are blue or tend to have a higher blue tint, unless exposed to sunlight. There is of course a genetic element, some babies being bluer then others, or returning to a blue color faster after being removed from the sunlight. Where I was speculating was with the rough green snake, since it is a basking snake rarely captive bred, the same may apply to it. In which case blue captive bred specimens would more common and less reliable as a distinct color phase, then wild caught.

Never heard of that before, but that does of course say nothing about your Statement not being true.
In Rough green snakes I suppose that it´s a genetic morph lacking xanthin. I´ve never seen green tree frogs or water dragons beeing blue
due to lacking UV exposure, but that could be lack of knowledge. That melanin increases with exposure to sunlight at least in mammals is common sense,
as far as I know reptiles are less prone to this, if so feeding carotinoids to reptiles does not always have an impact on colour expression (exceptions
are to my knowledge those reptiles depending very much on fruit, i.e. Rhacodactylus species, etc.)
However, my question aimed at experienced field herpers. I wondered if someone has seen those blue green snakes in their natural habitat.
Best regards,
Mathias Rath

In that case, no I have never seen a blue one in the wild. I would consider it quite a find. being a basking snake that depends on its cameoflage abilities, an axanthic specimen would be at a serious disadvantage. Naturally occuring blue in wild snakes is usually associated with markings intended to attract attention such as in the speckled racer, Drymobius margariterferus, or in unusual habitats such as that inhabited by the cave dwelling rat snake,Elaphe taeniura ridleyi. Axanthism is not an uncommon trait, however, in snakes in general, Axanthic corns, ball pythons, garters, and boas are commonly bred to name a few. So captive production would be probably be possible, if you could get by the problems with breeding this species, namely that they are short lived in captivity, and often difficult to aclimate.