You did a fine job Tosha
For more detail on egg production, read this letter copied from the VPI website.
I tried to make a link, but it was too long to fit in the "Link URL" box.
Here's the URL that you can copy and paste if you want to view it at their website:

http://www.vpi.com/VPIMailBag/vsforum.asp?fid=282&ftid=&fvt=1&gid=&iaction=2506&lst=&mid=757&mvt=2&nAction=2506&tid=&uid=&forumview=1&frm=1&ftc=&fte=&mte=&st=&sb=&so=0&valuetosearch=&action=3250

Brian


Dear VPI,
.......question........ovulation……define.......please.....

I believe there is general confusion on the forums about the terms follicle, ova, and ovulation--can you explain this ?

Thanks....J


Dear J
In general and to summarize as best as I can, this is how it works. The ovary makes an oocyte, which is a single haploid cell, the female equivalent to a single sperm. At some point later the ovary begins to deposit yolk and albumin (they are mixed together in a snake egg) around the oocyte in a process called “vitellogenesis.” At this point the oocyte becomes a “follicle”. While still in the ovary, the follicle increases to full size to become “mature,” meaning that at this point, once ovulated, it has the potential to be fertilized.

Typically, in an ovary there are several follicles that are maturing, but this may be happening at different rates. So prior to ovulation both immature and mature follicles can be present in the ovary. When a follicle is mature, it is full size, pretty much the size it will be when laid as an egg. When a female snake carrying mature follicles is palpated, the large follicles feel pretty much the same as eggs.

“Ovulation” is the process of the follicles being released from the ovary. Once released, a follicle is correctly referred to as an “ovum” . In snakes both ovaries release their follicles simultaneously. In a perfect ovulation, all of the follicles are mature. In a premature ovulation, some of the follicles are immature and will become the infertile egg masses known as “slugs.”

Prior to ovulation the growth of the follicles can be reversed and the follicles can be resorbed by the ovary. After ovulation there is no mechanism in the body to resorb ova or eggs—once the follicles are ovulated, in one shape or another, something is going to be laid.

At ovulation, the follicles leave the ovary and the ova are taken into the oviduct. This usually takes 8-24 hours and during that time there is a noticeable lump in the body just posterior to the midpoint of the length of the snake. This lump is caused by all of the ova being squeezed forward from the ovary from where they came to the open end of the oviduct that is located in front of the ovary.

Female ball pythons have two oviducts. An oviduct is basically a long tube that is open on both ends. The posterior end of an oviduct opens into the anterior wall of the cloaca and the anterior end of the oviduct is located at midbody, passing and just in front of the ovary on that side of the body.

The ova from the right ovary must go into the right oviduct and the ova from the left ovary go into the left oviduct. The anterior end of an oviduct is a bell-shaped opening called the “ostium.” An ovum is taken into the ostium, and then passes through the “infundibulum” where the sperm are already present and waiting. The infundibulum is a short length of the anterior oviduct that has microscopic folds in which the sperm are stored and nourished. It takes a snake sperm several days to swim from the cloaca, up an oviduct and to the infundibulum.

An ovum goes into the ostium, passes through the infundibulum where is it fertilized, and then passes on back to some point where it stays until egg deposition. All of that takes place at ovulation. Then during the ensuing time before egg laying, usually 40-60 days, the ovum is shelled. A shelled ovum is termed an “egg.”

And that is how it works. DGB





Dear VPI,
Okay...I am glad you made it simple.....LOL

I knew most of that (not all of the terms for certain body parts) but most of it.....

I hear other keepers say that female snakes actually use BOTH ovaries and oviducts every year. They then theorized that small clutches were perhaps due to one ovary or oviduct that was not working for some reason or other.

Is it possible that when a snake (a colubrid at least) becomes egg bound, that the cause is that she has 2 eggs trying to leave the two oviducts at the same time...and there is not enough room in the cloaca or the female doesn’t have the strength to push them both out?

Anyway, I have to admit that I thought that "ovulation" was when the ovaries created the follicles. I did not realize that mature follicles are big enough to actually feel. I thought single cells dropped into the oviducts at ovulation. Thanks for the info, J



Dear J,
I think you’ve got the concept down except for one misunderstanding—I may not have been clear on this, but I meant to say that in ball pythons and most other snakes, both ovaries grow follicles during the same period of time and the ovaries simultaneously ovulate. If a ball python lays 10 eggs, then some came from one ovary and some of those eggs came from the other ovary (it’s not necessarily 5 and 5).

When I said that the follicles from the right ovary go into the right oviduct (and from the left into the left,) I did not mean to imply that those two things were independent of each other. I was just talking about how things are organized in there. If the left oviduct is damaged, the ova from the left ovary cannot go over into the right oviduct.

You are correct that a female uses BOTH ovaries and oviducts every time she lays eggs. It’s possible that one ovary does not function and that is one possible reason why a female might lay a small number of eggs. However, if an oviduct doesn’t function for any reason, then the female will be unable to eliminate the egg masses (ova) produced by its ovary and the result will be the eventual demise of the female.

I’ve witnessed a lot of surgeries on egg-bound snakes over the years and I’ve never seen the cause of the problem to be that the eggs in one oviduct jam the eggs in the other oviduct. I can’t say that’s impossible, but I think it is very improbable.

In ball pythons, when a female ovulates, the mature follicles/ova at that time are full sized. It’s only in the ovary that follicles grow. Ova do not grow in the oviduct; there they are fertilized and the shell is added, I guess that they might increase in size a little bit, because of the shell and perhaps some fluids, but in the oviduct there is no more albumin and yolk added to the ova. DGB

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