Reptile & Amphibian Forums

I have a woma that seems to be gravid, I have been weighing her to check for weight gain and see none but instead actually loss.
My question is do woma's or pythons in general gain, lose, or remain the same weight during egg production? Anyone ever checked into this one? Thanks, B

This is typically what you will see with any gravid python. The mass gain in a gravid python is a perceived one due to the posterior girth increase caused by the developing eggs. It is actually a redistribution of body mass into the developing eggs, and not an actual gain in weight, and they will show a corresponding decrease in anterior girth.

Kelly

Ok great thanks! So would this mean a weight loss or just stay the same within about 200 grams or so? Thanks, Bradley.

Well, if you think about it . . .

They're often not eating, or eating only fairly lightly, but they're still metabolizing, pooping, and just living in general, along with producing eggs.

I'd expect an animal in that situation to be losing weight.

~Bruce

>>Ok great thanks! So would this mean a weight loss or just stay the same within about 200 grams or so? Thanks, Bradley.

I have collected a fair amount of data on the weight loss of female boas and pythons during reproduction. The best subjects are live-bearing boids because it is easier to control, and subsequently measure, the different aspects of the process. My best data comes from several successful reproductive efforts with green anacondas. I take initial weights shortly before ovulation. At the time of birth, I weigh all of the young and any slugs, weigh the newspaper substrate and all the accompanying fluids and subtract from the initial newspaper weight, and take the final weight of the female. I cannot account for any evaporative fluid losses immediately following birth, but I have calculated that these are not that significant.

There is always a net loss in weight of the female that cannot be accounted for. I usually see a total weight loss of 25 to 35% but there is typically about a 5% loss that does not include the combined weight of the fluid, slug, and egg mass. This 5% is the metabolic energy loss by the female with regards to maintenance of standard biological processes and the conversion of body mass into the production of the egg mass. So there is always going to be a slight net metabolic weight loss by the female throughout the period that she is gravid.

Kelly