Reptile & Amphibian Forums

When looking at pictures of green anacondas, I've noticed there are 2 basic color themes - a very green background or a very brownish background. Could this be locality specific?

my green female is only a couple months old and about 4 feet long. some days she looks green somedays she looks brown.

I agree, sometimes my anaconda appears very green, other times a bit brownish. Perhaps its the light. Perhaps its his mood. I know, for example, that boa constrictors can change color significantly from one day to the next. Still, some anacondas sure appear very brown.

` I once saw a color plate, in an expensive book, of a large Green Anaconda that was bright lime green, with much orange and yellow. You never can tell if it's just the picture that makes the color, or it's really a correct rendition. All I know for sure is that if I ever see one colored like that, it's going to cost me.

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The color differences could possibly be locality specific in some cases, however they have also found both colors in the same localized area. It is more than likely just the typical color variation seen within an average population. This is also seen with the huge color variations that are seen within a given population of boa constrictor from the same area. Brown is also indicative of age in many cases, as the majority of newborn greens have a mix of green and brown in their background color. A few newborns have a background color that is all green or completely brown. All green anacondas have a juvenile color phase that changes as they grow to adults. This is sometimes referred to as the ontogenetic color change. The vast majority of these young will change to the adult green or olive color within a year or so. The final adult coloration is obviously genetically based and probably reflects the coloration of the parents to a great degree.

Kelly

When I first got my Green it was a blue/green color. REALLY PRETTY! Then very shortly after I got it it turned brown. I tehn thought about it and noticed that I was using brown as most the color in its tank. So I changed the whole thing and everything I could possibly change is green in its encloser. I even put up green paper around teh sides of the tank. Bright Green Piet moss inside as well. And sure enough, now she is a beautiful green. It only took a few months for her to make this change. This pic shows her when I got her, the blue/green..though its kinda small and hard to see in this pic, but its the one on the hardwood floor. Then the two pics on teh right are the brown color she turned into when I put her in her brown encloser. Then the rest are pics of her now that she has had the green for a few months.
Now she has amazing bright green/yellow/and orange colors. But mostly just the beautiful bright green.

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http://photos.yahoo.com/gwas79
"The Critters"

That's an interesting observation. Green anacondas typically go through color shade changes periodically over hours, days or weeks at a time for no apparent reason. All of mine have always been kept on newspaper, and with no change in temperature or substrate color, they will exhibit extreme color changes from dark green to light green within a few hours that may last for days. But I have not seen full color changes (ie: brown to green ) as you have seen; it has always been a shade change of the same color. Actually many boids will show this same behavior, but not to the degree I have seen with most greens. During our 2001 breeding, when my female ovulated, she became so dark green for a few weeks that she looked almost black.

Kelly

And starting to wonder what other colors or shades they can trun. For instance.....what would happen if the enitre backround were red, yellow or blue, etc.? Like I said, when I got her she was a blue/green color. It was more a pretty dark blue with a tinge of green mixed in. I wonder if the newspaper makes it hard for them to blend themselves in which is why they keep changing shades? Mine has also been almost black in color as well. This happened while I was remodling her home. I kept her in "her" bag.
It's the only bag she will willingly go into. She will bite if I try to put her in any other bag! Really funny. But I had her in HER bag for a few days and she was pretty dark. So heres a pic of that too. heheh..I love taking pics of Siren. She's so pretty. BTW...what is a "BOID"?

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http://photos.yahoo.com/gwas79
"The Critters"

A boid is a python or boa.
Peace

I don't really think the background color alone has a lot to do with the color changes they exhibit, as in most captive situations they are exposed to a consistant background. I feel it has more to do with thermoregulation or possibly presence/absence of stress. Both of which could explain why yours showed a darker coloration when it was held in the transfer bag. Just my thoughts on it.

Kelly

I agree with what Kelly said in her 2nd to last post. Snakes have evolved for in favor of phenotypic plasticity, simply put, variations in color within species, and although we know genetics is of course involved in perpetuating this, what is less known are the specific patterns - where existent - caused by genetic drift, gene flow, sexual selection, etc., in anacondas and other snakes world-wide.

The colors of snake skin are determined by chromatophores hemoglobin, carotenoids, and the structure of the skin itself; depending on the species (keeled scales or no, colorful corn snakes vs black rat snakes, etc.) Patterns are determined by the arrangements of the different colors, and the aspect of the spectrum of incident light reflected to the observer - i.e., what our mammalian eyes see - is based on both pigmentary and structural patterns. As the many breeders of albinos and so-called albinos know, genetic and embryonic environmental factors, especially genetic, are known to cause anomalous color, pattern, or both.

Anacondas of course aren't like chameleons, octopus, or halibut, they can't change to fade in with the background colors when the colors change (they don't habve the right chromatophores), but certainly age, health, and thermoregulation can add variety to the green-gray-yellow-brown hues seen in one individual, we saw this among the populations in Venezuela. Also, their skin is sensitive to light just like many of us - it was obvious that a (larger) snake had recentlly eaten, if not by the big lump, then by the broad patch of black skin, where the anaconda had been sunburned where her skin ~mid-body, covering her gut full of digestive gases, had floated to the top of the water and been exposed for many hours to sunlight.

I've never read this book on the subject, but the review was good:

Reptile and Amphibian Variants: Colors, Patterns, and Scales, by H. Bernard Bechtel

It sounds like a good read, anyone ever read it?

Renee

Sounds like a fairly major change in color. I may try the same thing myself.