Reptile & Amphibian Forums

Shane,
I haven't been around lately or I would have posted a comment sooner. For a weight of 144 pounds at 13 feet, that female green of yours must have some pretty good bulk to her. I would really like to see a photo of her. During the study Rivas conducted in Venezuela, he and his group collected data on almost 700 individuals. The females that they measured around 13 feet typically weighed between 90 and 135 pounds. So your female may be a little heavy but not too bad. The lighter females in this range probably had recently given birth, were compromised for some reason, or were not feeding as successfully. The largest I have at my place is the female below. My daughter is not a fan of large snakes, but I did get her to take this photo. This female is right at 14 feet and 126 pounds. She is solid for her length but definitely not overweight. I would like to put a little more weight on her before we put Jud's male in with her in a few months. I have another 3 year old female green at 11 feet and probably about 75 pounds, so that would give you another for comparison. If you doubt your scale, you might check it with something weighed on another calibrated scale. Thanks for sharing your information.

Kelly

Actually, Kelly, your numbers for the weights of the snakes we caught in Venezuela are a bit high over all. Also, where did Peter publish those data for the weights you quoted, for wild caught murinus? thanks -

The problem in comparing wild caught to captive is that obviously captive snakes simply eat way more than their counterparts in the wild, and they move a hell of a lot less.
Every time I go to any zoo and check out the snake collections, I am really stunned by how obese many of the snakes are.

Regardless, here are a few numbers, Shane, to give you a rough idea of the typical weights to length ratios we found - (females)

16.0 ft, 114 lbs (very thin)
14.3 ft, 126 lbs, breeding (this was "Godzilla", now a starlet thanks to the Nat Geo film)
13.3 ft, 75 lbs, breeding
11.4 ft, 58 lbs, breeding
13.8 ft, 81 lbs (had recently eaten a capybara)
13.7, 108 lbs, gravid - after giving birth weighed 66 lbs.

One of our heaviest (> 16 ft.) weighed 210 lbs (breeding condition).

So, compared to wild E. murinus of the llanos, your snake is very fat, particularly due to the likelihood that (and I could be wrong) your length measurement is a bit high, simply b/ most people's are, even those of zoo snakes (be sure and do the string measurement along the mid-line, at least 3 times, and take the average of your results). But compared to other captive couch potatos of relative length, it's probably just chubby. I can't say what the potential risks are for "obesity" in these snakes, but no doubt they exist as much as they do for mammals.

To answer the other Q about the world's largest snake, it's safe to say the green anaconda could win, since it is aquatic and thus weight and gravity are less of a problem to overcome (hence the incredible girth they can achieve), as opposed to the retics, who typically are tied with anacondas for extreme length potential, but do have longer heads than Eunectes, relatively speaking.

Renee

Renee,
I acquired the weight and measurement ranges from the 2000 Rivas dissertation. After your post, I checked again and found out why the ranges I posted were a little high. I posted the ranges for 14 foot greens to Shane as if they were for 13 foot females. I was not only looking for ranges on Shane’s snake, but also for the 14 foot green I have here and accidentally transposed them. The correct ranges for typical wild caught female murinus from his study are about 70 to 120 lbs for females around 13 feet, and about 90 to 135 lbs. for females around 14 feet. Sorry for the confusion. It does looks as though most of the specimen data you posted falls fairly well within these ranges, except for the very thin 16 foot specimen. I totally agree on the excessive weight issue with captive Eunectes. They are probably one of the most obesity prone snakes in captivity due to their lower metabolic rate. You have to really watch their food intake. I don’t know how Shane measures his female, but I have had excellent results by allowing them to stretch out straight along a wall with just a little help. I am fortunate they are calm enough for this procedure, as it obviously would never work with any wild caught anaconda or an aggressive, or nervous captive snake.

It looks like Shane acquired the two measurements and weights from an article Peter published in Reptiles Magazine in November of ’97. The 16’ 5”, 232 lb. specimen was from R.R. Mole (1914) and the 16’, 118 lb. specimen was caught by Peter and his group on the Macanillal River in Venezuela. There is a photo of the 118 lb. female and she looks fairly thin, possibly post-parturition. Other records I have seen for larger specimens include 19’ and 236 lbs. from Pope (1955), 18’, 180 lbs. from Strimple (1993), and 16’ 6”, 108 lbs. from Barton & Allen (1961). This 108 lb. female must have also been quite thin for her length. I think the 14 foot female I have here is pretty close to breeding weight going by all of the data that you posted. Thanks again for your information as it does give an excellent picture of anaconda metrics in their natural state.

Kelly