Reptile & Amphibian Forums

Good to hear from you again. I checked with Shaun at the Milwaukee County Zoo and their male is definitely quite large. They acquired him from the Bronx Zoo years ago when he was about 5 to 6 feet. Unfortunately his records did not show an acquisition date, so he is not sure of the age. He said their male is right at 12 feet and 76 pounds. Not quite as long as Jud's male, but is 8 pounds heavier. Their male is definitely the second longest one I know of.

As far as maturity and producing sperm, I have seen one male I have produce sperm plugs at 2.5 years of age. He was 7.5 feet at the time, and size plays a part in this as well. You would probably not see this in a 2.5 year old male if he was only 5 feet for example. Unless while actually in a breeding situation with a female, he would probably not be depositing actual semen, but would be depositing sperm plugs that look like inch long strips of light brown rubber-like material. At the size and age of your male, I would think that he would probably be sexually mature.

Aside from this, it does sound like from your description that you have a male. When less than a couple of years of age, while the female and male spurs are of similar size, they do have a different shape. As greens get beyond three years or so and larger, the male spurs start becoming more prominent, longer and darker. The female spurs actually recess further as she gets older and become more difficult to see unless you push the skin aside and dig for them. I posted some photos below for comparison. The first photo shows the spurs of the female, currently being bred, taken several years ago when she was 9 to 10 feet. The spurs are fairly small and beginning to recess. The second photo is of the young male I spoke of above when he was about 8 feet. The spurs are completely external and light in color, still relatively short, but show the distinctive male hook shape. The last photo I took today and is of Jud's 17 year old male. The spurs are totally external, and have grown darker and quite long with age. They have actually grown so long over time that the classic hook shape has become elongated. Hope this helps some. Thanks,

Kelly

Thank you for confirming the size of that male. Craig (their head reptile keeper) gave us a tour of the facility a few months back and I thought he was full of it when he said their snake was a male.

My snake does not seem to be producing plugs, rather actual sperm. At least this was the opinion of a vet recently, but it has not been taken under a scope. Im actually getting concerned it is some kind of infection and is a mucus secretion. I was having things checked out later this month, but I might just speed up the date on that.

As for the spurs, 2 months ago, they were recessed into the scales. You had to dig hard to find any hint of spur and they were way down there. Then all of a sudden, they "popped out" in early March. I will get a photo to see what you think, but I'm pretty sure we have a nice hook at the end now. My thoughts on why they just popped out now is that it correlated with maturity and the season.

Thanks for the photos to compare. I have seen yours before and this was how I was making the connection that it was female for so long. Now we have a new snake : ) I knew what I was seeing the second I saw them. Now I just hope he gets as big as Jud's and the MCZ male. This snake is worth his weight in gold for educational programs having such a docile green anaconda.

Lets just hope he is in good health

I had the mysterious discharge checked out today. Apparently it looks like skin under a microscope, so it is not sperm. Since we know it is not skin from the surface of the snake, I do not know what is going on.

Is it possible this snake has been shedding a lining of its sex organs fairly consistantly for about 2 or more months?

Sounds like a normal hemipenile skin cast. These are a often found when probing male snakes and assumed to be sperm plugs. I'm not sure if any boa or python species actually produces sperm plugs.

Ernie Eison

with your comment on the sperm plugs. Every mature male boa or python I have owned has always produced seminal plugs when reproductively active, either while being cooled in preparation for breeding, or during courting of the female and periods between copulations. I have never see them being produced by mature males at any other time or under any other circumstances. Mengden has a paper in The Reproductive Biology and Diseases of Captive Reptiles, by Murphy and Collins, where he found that sperm counts were highly elevated in male pythons only when seminal plugs were present as well. It appears that these seminal plugs are composed mostly of dried semen. However, from the description given by E4, it does sound like the particular objects he is seeing could be what you are referring to, and not seminal plugs in this case.

Kelly

" If you sexed this snake with a probe and did it correctly and there was some of what is (incorrectly) referred to as a "sperm plug" on the probe when you withdrew it, then I would say there is a strong probability that this animal is a male. A python "sperm plug" is better referred to as a "hemipenial cast" and is comprised of shed hemipenial skin and dried mucus, with probably a dash of the reptilian equivalent to smegma. We've never seen it form in a female python.

No species of python has or makes sperm plugs. A sperm plug is a waxy deposit that a male of some species of snakes (gartersnakes, for example) leaves in the gonadal openings of a female after copulation--the sperm plug blocks the sperm of other males from getting into the oviducts. " DGB

In most boas I would think that sperm plugs would be unnecessary. Anacondas could be a possible exception for the obvious reason that they form a breeding balls, many males on one female at the same time so the productions of a sperm plug would be useful. Other boas and pythons combat to determine which male breeds. Ernie Eison

semantics and definition. "Sperm plug" is essentially a loose term so to speak, and may not be the most accurate term for these objects. A true sperm plug is exactly what Dave described, and they have been noted in other Classes and Orders of animals, as well as some snake taxa as he said.

I would agree that hemipenial casting could possibly be a more accurate definition in that these castings are partly tissue and skin casting from the hemipenes, but other researchers have found them to have a significant percentage composed of dried semen as well. Both Dr. Richard Ross and Jesus Rivas both use the term “sperm plug” to indicate these objects in male pythons and boas. Additionally, and more interestingly, some other researchers feel that these “hemipenial castings” may actually perform the same function as true sperm plugs by blocking sperm penetration and fertilization by other males.

As far as male combat, greens in a breeding ball are combating analogous to other boids, they are just doing it on the female and at her cloacal opening. Richard Shine has commented on the fact that females of several other python taxa have actually been observed in the field being courted and copulated with by multiple males in succession. It is just that the combat did not occur on the female, and the aggressor didn’t totally deter all other males from copulating with the female. Great discussion topic.

Kelly

Sure I agree sperm plug as it applies to pythons and boas is really herpetolocultural semantics / slang. Sort of a nick name to describe a commonly seen event. The use of the term sperm plug in snakes might be a bad choice all together.

I gave the anaconda breeding ball analogy because the general methodology is the closest thing in boids that I can think of to what happens in garter snakes a snake known to produce plugs. If looking for a boid that produces "sperm plugs" as currently defined this would present a good scenario. Species known to produce these plugs tend to mate in large heavily male biased congregations.

In garter snakes the use of sperm / copulatory plugs isn't so a male can eliminate sperm competition it's so the females don't get badgered to death. Literarily. Once female garters have been mated and carry a plug they give off a post copulatory pheromone. During this time the males don't pursue them. The mated females have a chance to disperse to areas where the male population is significantly less while the males place their emphasis on unmated females. The advantages to this strategy are obvious. Once away the previously mated females plug dissipates.She no longer gives off the pheromone. Most females end up being bred by other males and giving birth to multiple paternity litters.The high incidence of multiple paternity strongly indicates that the primary purpose of the plug is not to secure the passing of genes via a singular male but to protect the females from being over taxed. The use of a plug in these animals is not for selectivity but to create a sense of order out of chaos. If you look at the Shine observation it's possible to conceive that the use of combating serves the same purpose.The males combated away from the female then bred her in secession.The female is protected from being over taxed by to many males attempting to breed her simultaneously with the likely end result being a multiple paternity clutch. Again it's not about selectivity in a mate it's about protecting the female.

Ross and Rivas use of the term sperm plug, biologist and academics are not above the use of improper or inaccurate generalized terminology.

Ernie Eison

post you made. After you included this quote in your May 9th post: “A sperm plug is a waxy deposit that a male of some species of snakes (gartersnakes, for example) leaves in the gonadal openings of a female after copulation--the sperm plug blocks the sperm of other males from getting into the oviducts.” You then seemed to contradict this statement in your May 11th post with the comment: “In garter snakes the use of sperm / copulatory plugs isn't so a male can eliminate sperm competition it's so the females don't get badgered to death”.

Actually, your first quote was correct, most studies have shown that these copulatory plugs do indeed act as a physical barrier to the semen penetration of other males, and do act to eliminate sperm competition. The post copulatory pheromones produced by the females that reduce her attractiveness have never been shown to have a direct relationship to the presence of the plug. They actually appear to be produced by skin secretions with a more direct correlation with the recent act of mating and not the concurrent deposition of the plug itself.

I would disagree with your assessment that the primary purpose of the plug is not to secure the passing of genes via a singular male. I believe that to be exactly the primary function of the plugs. I don’t believe a mating process would ever evolve that would effectively exclude the individual males advantage and ability to pass on its own genes to the exclusion of other males. The whole process of selection in the reproductive process is to allow an individual to pass on its own unique genetic material at the exclusion of competitors. This is the current theory behind the reason why true copulatory plugs never evolved in boids, and why they did evolve in gartersnakes.

The length of time that male gartersnakes are actually engaged in copulation with a given female can be measured in minutes. Copulation in boids is usually measured in hours, and sometimes days. Male gartersnakes have a very short window during each year in which to pass on their genetic material. With large numbers of females in one place, it is a very definite genetic advantage for them to be able to successfully reproduce with as many females as possible in a short amount time. For males with the greatest fitness to have the ability to rapidly mate, deposit a physical barrier to a competitors sperm, and then move on to another female, has great advantages for any given male to pass on his genes to as many females as possible. Male boids produce the same effect as a copulatory plug by their process of prolonged copulation, which effectively acts as another type of physical barrier to competitors sperm. This is especially true when breeding in a male congregation as with anacondas. Greens are probably less likely to produce plugs based on what I have read in field studies and what I have seen personally. It is not unusual for them to remain connected for over a day, and these extended periods would have a definite barrier effect in a breeding ball.

I believe it is all about selection and genetic fitness within a given population.

Kelly

"The post copulatory pheromones produced by the females that reduce her attractiveness has never been shown to have a direct relationship to the presence of the plug. "

A study published in 2004 involving garter snakes determined a very strong relationship between pheromones and the presence of the copulatory plug.

After being bred and the plug inserted females give off pheromones that discourage males from perusing them .The length of time these pheromones are present coincides directly with the presents of the copulatory plug. During this time the females disperse . Once away from the pack the plug is displaced and the females stop giving off the pheromones. In most cases she is successfully mated by other males. A high occurrence of multiple paternity litters is seen .

As a block against sperm competition copulatory plugs are ineffective .The high incidence of multiple paternity is evidence. They do effectively work in preventing the females from being over taxed .

Like I said from the start I think anacondas would be a likely candidate to employ a similar system. I haven't read all the research but I would really be surprised if no one has noted the presents of implanted "sperm plugs" in females of this species during mating. I would also expect the same initial conclusion of it's purpose as a way of defending against sperm competition to be drawn . I think the production of a copulatory plug in green anacondas would also prove ineffective in the prevention sperm competition for several reasons. One being the strength of the animal. Rival males that out muscle the previous male could dislodge the plug. Also if the presents of these plugs were effective as a block to other males why would the successful male continue to expend energy in the ball ? It's plausible that these snakes could benefit from the production of a copulatory plug in a similar manor as seen in the garter snake.

Using their body as a physical barrier is the way males try to prevent other males from mating . The green anacondas version of physically enforced selectivity. The production of a copulatory plug would be secondary in nature. Unlike other boas that use ritualize combat away from the female , green anacondas all pile up on the female simultaneously. As you noted the length of time can be substantial and unlike combat in other boas this has direct physical implications on the female. Like with garter snakes the plug would serve a greater use if it could somehow alleviate pressure on the female.

I don't see where I contradicted myself in anyway . You paraphrased a portion of a quote from Dave Barker that I included in a post entitled ( Heres what Dave Barker had to say ) and compared that to a direct quote from me that disagreed with only that segment of Dave Barkers quote and nothing that I directly said. Ernie Eison

I could only assume that you included that particular section of Barker’s comment because you were using it to support your assertion. Otherwise you would not have needed to include it in the full quote to provide evidence for your position. That was my mistake if I misinterpreted your intent.

There is an event correlation between the plug and post-copulatory pheromone production, but it is not a causal correlation. Studies have shown that unmated females smeared with copulatory plugs remained reproductively attractive to males, whereas females smeared with copulatory fluids not associated with plugs rendered the females unattractive to males. The lack of male interest in the females even when their plugs had been removed after a recent mating provides further evidence for this assertion. The plug itself is not the source of the pheromones, and this was the point I was making in the previous post, and what I meant by no direct relationship.

I think we both agree on the lack of need for plugs in the reproductive process of boids. Additionally, male combat is not a guarantee that the victor will be successful at mating, as other males are at times more successful. Male combat in boids could just as easily be an evolutionary artifact that no longer has the importance in these species that it once had millions of years ago in ancestral species. The physical barrier produced by prolonged copulation in boids probably negates the necessity for the evolution of plugs in these taxa. The extremely low metabolic rate of greens would also preclude any issues associated with detrimental effects on the female from the attention of large numbers of males at one time, and for a prolonged period.

This copulatory plug system is rare in snakes, in fact, they are not even produced by all gartersnake species. Their production appears to have evolved only in the few species that have a very narrow window of breeding opportunity each year.

Kelly

The 2004 Shine, Mason, Ford and O'Donnell study on Red Sided garter snakes showed the presents of copulatory pheromones along with the presents of the copulatory plug go hand and hand. The two things are tied together.

Both the production and the decay of the signal produced by the copulatory pheromones directly coincides with the presents of the copulatory plugs .While the plug itself may or may not be the pheromones source it presents is necessary.

The combination of factors that go's into the production of copulatory pheromones is not known. What was determined was these pheromones are produced as long as the copulatory plug is present and that the females benefit from the production of the pheromones because they allow them to avoid further courtship and to escape to summer feeding grounds where most were once again mated. The use of copulatory plugs did not prove effective in providing exclusivity to the male.

"The lack of male interest in the females even when their plugs had been removed after a recent mating provides further evidence for this assertion. "

The study I cited addresses this point and showed that summation to be incorrect. The interest males showed in females that had lost their plugs was exactly same as unmated females.

I'm not ready to buy into the notion male combat in boids is an evolutionary artifact that no longer has importance in these species. I think in nature it plays an important role . Ritualized combat is wide spread in the animal kingdom and can be found in advanced snakes.

"The physical barrier produced by prolonged copulation in boids probably negates the necessity for the evolution of plugs in these taxa."

I think it negates the necessity to produce copulatory plugs as a primary means of mate selection but not if they serve another purpose as seen in the red sided garter snake. For reasons already outlined I feel green anacondas are prime candidates for the production of copulatory plugs in this respect . Ernie Eison

I believe we have been in agreement on some points all along.

“Both the production and the decay of the signal produced by the copulatory pheromones directly coincides with the presents of the copulatory plugs .While the plug itself may or may not be the pheromones source it presents is necessary.”

I was in line with this statement previously. I agreed the correlation was there, just that the source was not synonymous.

“The interest males showed in females that had lost their plugs was exactly the same as unmated females.”

I agree with you and this is correct as applied in the referenced study. However, this statement from the 2004 study was in reference to females that had lost their plugs through natural disintegration approximately 2 days after mating when the pheromones were naturally declining as well. I was referring to plugs manually removed shortly after mating when the pheromones were still elevated. The 2004 study did not address this specifically as was done in the previous studies.

I obviously agree that ritualized male combat is wide spread in the animal kingdom and can be found in advanced snakes. However, it is very inefficient when applied to even advanced ophidians, and is not anywhere near as efficient in their reproductive strategies as is seen in higher vertebrate Classes. Due to this inefficiency, it would be difficult to ascertain whether this behavior was in a state of evolutionary decline or advancement, especially since it is seen in only some of the species within this Order. It was strictly a possibility on my account, and not meant to be an accurate assessment of their current reproductive behavior.

I am not ready to accept the idea of the evolutionary need of copulatory plugs in boids. Their reproductive behavior is completely different than that of T. sirtalis. Large numbers of male boids never have access to large numbers of reproductively active females simultaneously over an extremely short period of time. Less than a dozen species of snakes under these unusual conditions are currently known to have evolved this plug strategy and can benefit from it. Not all, but most boid species, as well as green anacondas, have a relatively low population density as compared to most other snake taxa. Due to climate, habitat, and lack of true denning behavior, the chances of large numbers of males encountering receptive females simultaneously are not great. The selective pressure to evolve copulatory plugs in these species does not exist.

Green anacondas are unusual for boids in that males do reproduce in mass on single females. This is mainly due to the scarcity of reproductively active females of this species in any given year. In its natural environment, an average mature female green typically is reproductively active only every third year. They are also quite spatially dispersed. With active females this scarce, it has been shown that once a male encounters a reproductively active female, he stays with her the entire season, and does not move on to look for other females. This is why the breeding ball is so prevalent in anaconda reproduction. Additionally, once engaged with a female, the male usually remains connected with her for many hours, and sometimes days. This effective barrier has seemed to cancel the selective pressure for the evolution of copulatory plugs in this species.

Kelly

This actually appears to be like a discharge of sperm into water. It is able to be picked up, but is hardly solid. It actually seems more like a thick mucus discharge. However, if it looks like skin under a microscope, and doesn't have sperm swimming around...its not sperm.

I am sort of unclear what you are describing. If you are suggesting it is a cast similar to the paired casts we see discharged from pythons during breeding (commonly called sperm plugs), it certainly isn't that.

These are long and thin discharges. If I had to describe it in another way than what I said before, it would look like what you might imagine it would looks like after an anaconda took a really thin condom off each hemipene and left it in the water.

What is the size in millimeters of these objects?

Kelly

Kelly, I have not measured them, and they would stretch. Also, they are long enough to estimate in inches. I would say they "float" in their relaxed state at an average of about 3-5 inches.

Interesting, I have never seen anything of that size produced by any of my greens. All of what I refer to as sperm plugs that I have seen are about half that size at best.

Kelly

Hello Kelley:
What is the status of this years project?
I am interested in a light green male if any are for sale this year.
Thanks!
Tom Dobrov