Reptile & Amphibian Forums

I have a green anaconda that is 3 feet 7 inches. It was sold to me as a female but look at its spurs I am not too sure it is a female. Its spurs are definitely visible. I have seen the postings on here comparing the mail spurs to female spurs but those looked to be on snakes that were quite a bit bigger. I’ve also read posts saying that is possible to sex a younger snake buy looking at the spurs, but that the size is not the determining factor but rather the shape. I was wondering if anyone cold show me or describe some of the subtle differences in their spurs. Also I was wondering how effective the palpation method of sexing a snake is with green anacondas.
Thank.

Kevin,
Very young greens can be accurately sexed by the spurs if you have seen a lot of them for comparison and know what to look for. As in boa constrictors, it is not the presence, absence or size of the spurs that is important in very young greens, but the structure and shape of the spur that distinguishes the difference between male and female. Any green over 5 or 6 feet is fairly easy to spur sex because the structure of the spurs have developed and diverged between the two sexes to the point that it is easier to distinguish between the two. However, with greens smaller than this, it will take quite a bit of practice, especially with neonates as the differences between the sexes at this age are extremely slight. I use a binocular scope at 10 power to sex newborn anacondas and boa constrictors, but other magnifiers will work just as well.

Young females under 6 feet have external spurs similar to the males, and the only way to differentiate the two is by structure alone. As the males age, the spur stays external and they retain the hooked shape similar to a wide based cats claw. The male spur is also connected at the end of a significant appendage which you will never see in females over 5 or 6 feet. The females spur has less of a hook shape and is relatively smaller and wider with a more conical, bud type shape. As the females age and their length gets into the 6 to 8 foot range, their spurs become recessed into a cavity, and they can not be easily seen without pushing the surrounding scales back away from it. In larger females, you can usually only see the very tip of the spur at best without pushing back some of the surrounding scales.

If you can post close-up photos of your greens spurs, I might possibly be able to tell which sex it is. Thanks,

Kelly

Hello Kelly,
I tried to get a pic, but the quality of the photo was pretty bad and not worth putting up. The spurs look like a tiny cat claw attached to a easily visible appendage. I tried to probe the snake and it went about 1cm deep, it was about 3 to 4 scales. I am not sure it this indicates a female or if it is just a male tensing up. Thanks for your input.

Kevin,
Your description sounds like a male, except for the depth, but very young females can sometimes be deceptive. Probing is a little difficult with young greens, and does take some practice. Greens have a different structure within the cloaca than other boids and require a different probing procedure than most other snakes. The probe first needs to be inserted into one side of the cloaca opening perpendicular to the body, and in about one-third of the way through the tail base or just slightly more. Holding it steady, and without allowing it to move back out any, rotate it parallel to the body and move it back into the tail as you would probe any other boid. All of this needs to be done very slowly and easily to avoid injury. If you are not familiar with probing boids, I would find someone who is that could do this for you. If you do have a fair amount of experience, it shouldn’t be a big problem for you at all. It may take a few tries, but if you take it slowly, there won’t be any problems. If done incorrectly, most of the greens you probe will appear as females. The true females will only probe two or three subcaudal’s, males considerably more. Good luck, and let me know how it goes.

Kelly