Tetrapod Zoology

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Popular culture would have it that turtles are weak, flaccid, crappy organisms with dull social lives, stunted and barely functional internal organs and – it goes without saying – undersized sex organs. Right? WRONG…

Warning: the following blog post may be considered unsuitable for viewing by minors.


Believe it or don’t, turtles are horrifically well-endowed, and if the thought of learning more about the genitals of these oh-so-surprising reptiles doesn’t appeal to you, look away now. Last warning. Ok, here we go. To begin with, I have to confess that I actually know very little about the subject I’m writing on, and this is despite a reasonable amount of literature-based research. I have also never dissected a turtle, nor manipulated a live turtle’s genitals, so if you know more about the subject than I do, and/or have any amusing anecdotes or personal adventures you’d like to relate, please do feel free to chip in.

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Hydraulic intromittent male sexual organs – or dicks – are not unique to mammals among tetrapods, but are also present in squamates, archosaurs and turtles, and this phylogenetic distribution has led some authors to conclude that these organs were present in amniote common ancestors. However, in their details, the organs of these groups are all quite different and actually formed from non-homologous tissues. As shown by Kelly (2002) [and covered by Pharyngula last year], male intromittent organs therefore arose independently among tetrapods on more than one occasion. The turtle organ, for example, contains only one vascular erectile body and develops on the ventral surface of the cloaca, whereas the mammal organ contains two erectile bodies and is derived from non-cloacal tissue [in the diagram above - borrowed from Kelly (2002) - intromittent organs of turtles, birds, mammals and snakes are compared in transverse cross-section. VS = vascular space; TM = tensile membrane. Note how different the organs are in their cross-sectional structure].

Before going any further, what is it with my use of the term ‘organ': why aren’t I using the familiar term ‘penis’? The reason is that this might not be the right word to use, though this does depend on who you ask. According to one school of thought, ‘penis’ should be restricted to the organ present in mammals, and the non-homologous but convergently similar organs of turtles and archosaurs should be termed a phallus instead (T. Isles, pers. comm.). Not everyone goes along with this: some biologists who have published on intromittent organs consistently term all of these organs penises (e.g., Kelly 2002, 2004, McCracken 2000). For what it’s worth, I personally prefer to restrict ‘penis’ to mammals.

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Like the mammalian penis, the turtle phallus is a hydraulic cylinder that becomes engorged by fluid and is relatively resistant to bending when erect. The single erectile body of the turtle phallus is divided into a collagenous corpus fibrosum and a highly vascularized, expandable corpus spongiosum. As a turtle’s phallus inflates, its length may increase by nearly 50%, its width by 75%, and its depth by 10%. A 50% increase in length doesn’t sound too impressive, so I assume that even an uninflated phallus – tucked away inside the cloaca – is large. However, the corpus fibrosum increases in length somewhat as well, and hence may contribute to the total length of the erect organ. More on the issue of size in a moment.

A pair of long retractor muscles extend for most of the length of the phallus’ dorsal surface, and attach within the body cavity to the lumbar vertebrae. When at rest, the phallus is actually doubled up on itself within the cloaca, and it is the contraction of the retractor muscles that causes the phallus to un-double and protrude (Gadow 1887). Bishop & Kendall (1929) found that turtle phallus retractor muscles were ‘physiologically rugged’ and of ‘extreme endurance’.

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Collagen fibres reinforce the phallus wall and are arranged either along, or perpendicular to, the phallus’ long axis, and in this respect the turtle phallus is superficially similar to the mammalian penis. However, while the mammal penis only has one layer of long-axis fibres, and one layer of perpendicular fibres, the walls of the turtle phallus exhibit multiple layers of these fibres. This array of stiffening collagenous fibres is still, however, highly similar in turtles and mammals: a fact which led Diane A. Kelly to title her 2004 paper ‘Turtle and mammal penis designs are anatomically convergent’ (Kelly 2004). The strong similarity observed in the erectile organs of these phylogenetically disparate groups indicates that there are few functional solutions permitting the evolution of cylindrical, inflatable intromittent organs (Kelly 2002, 2004). Kelly is well known for her previous work, widely reported in the media, on penis anatomy in armadillos (Kelly 1997) collected as roadkills near Tallahassee, Florida. Note that the title of Kelly’s 2004 paper includes that most evil of words in biology: design. It is to be avoided at all costs, for reasons that I don’t need to elaborate on, I’m sure. Anyway, her publications can be obtained, free, from her homepage here.

As interesting as it is from the point of view of embryology, phylogeny and microanatomy, what is particularly eye-opening (no pun intended) about the turtle phallus is how frighteningly large and formidable it is in some species. Again, I can’t pretend to have much useful experience in this area, so do help out if you know more. From the images I’ve seen, it seems perfectly normal for some tortoise species to have a phallus that is half the length, or more, of their plastron. I would guess that in a tortoise with a total length of 20 cm, the phallus might be 8 cm long. Look at the images accompanying this article, some of which show better-endowed species/individuals than others. The organ is always dark – grey, purple or blackish – with an expanded head and a sharp spine at its tip. To date I’ve only seen the organs of testudinids and emydids, and would like to know if other turtles are the same in these respects.

While it might seem like a bloody stupid question, one has to wonder exactly what it is that turtles do with these sometimes enormous organs. As in other tetrapods that sport proportionally large sexual organs (including certain ducks, cetaceans and, yes, some primates), observational data suggests that turtles might employ their members in display or aggression. Honda (2001) had this to say about captive specimens of the box turtle Terrapene carolina

Sometimes males will distend their organ neither while mating, nor while in the presence of females. Usually while bathing or drinking, the turtle will submerge the front half of his body, rise up on his back legs, and drop his organ through the cloaca. It is a sight to behold, and one that can startle both novice and experienced herpetoculturalists alike. The organ itself is large in proportion to the turtle, and dark purple in color. After several seconds, the turtle will retract the organ back through the cloaca. It may repeat this process once or twice.

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I also note the title of a very interesting paper by de Solla et al. (2001): ‘Penis displays of common snapping turtles (Chelydra serpentina) in response to handling: defensive or displacement behaviour?’ [adjacent image shows mating snapper pair]. Unfortunately I have yet to see this paper (a pdf doesn’t seem to be available), so I don’t know if they concluded whether defensive or displacement behaviour better explained the phallus displays they reported. Please let me know if you know the answer (or, even better, can send me the paper). Without information to the contrary, I cannot help but imagine that some turtles might be in the habit of intimidating enemies with their erect 20-cm long, black, spike-tipped phalluses.

Now there’s a thought. You might never look at a turtle the same way again.

For previous posts of mine on turtles see the series on snappers and alligator snappers here and Tortoises that drink with their noses. More on turtles in the near future, including stuff on Gilbert White’s pet tortoise, J-Lo the araripemydid and pleurodire diversity, and meiolaniids.

So, tomorrow (Monday) is the big day…

Refs – –

Bishop, G. H. & Kendall, A. I. 1929. Action of formalin and histamine on tension and potential curves of a striated muscle, the retractor penis of the turtle. American Journal of Physiology 88, 77-86.

de Solla, S. R., Portelli, M., Spiro, H. & Brooks, R. J. 2001. Penis displays of common snapping turtles (Chelydra serpentina) in response to handling: defensive or displacement behaviour? Chelonian Conservation and Biology 4, 187-189.

Gadow, H. 1887. Remarks on the cloaca and on the copulatory organs of the Amniota. Philosophical Transactions of the Royal Society of London B 178, 5-37.

Honda, M. 2001. Chelonian notes. Art Journal 60 (2), 96-100.

Kelly, D. A. 1997. Axial orthogonal fiber reinforcement in the penis of the nine banded armadillo (Dasypus novemcinctus). Journal of Morphology 233, 249-255

– . 2002. The functional morphology of penile erection: tissue designs for increasing and maintaining stiffness. Integrative and Comparative Biology 42, 216-221.

– . 2004. Turtle and mammal penis designs are anatomically convergent. Proceedings of the Royal Society of London B 271 (Suppl 5), S293-S295.

McCracken, K. G. 2000. The 20-cm spiny penis of the Argentine lake duck (Oxyura vittata). The Auk 820-825.

Comments

  1. #1 Baratos
    April 30, 2007

    OH GOD IT BURNS!

  2. #2 chezjake
    April 30, 2007

    I’m afraid I can’t add anything in the way of definitive knowledge, but your post is definitely enlightening. It also sheds new light on the old Ogden Nash verse:

    The turtle lives ‘twixt plated decks
    That practically conceal its sex.
    I think it clever of the turtle
    In such a fix to be so fertile.

  3. #3 Zach Miller
    April 30, 2007

    You know what they say: once you go terrapin, you never go back.

  4. #4 Monado
    April 30, 2007

    Some mating turtles, at least, are more or less at right angles, i.e. female horizontal, male vertical, and it seems to be strenuous for the male, who is generally gasping with effort.

  5. #5 Dave Hone
    April 30, 2007

    Personally I don’t have a problem with the word ‘design’ in biology, in the context of “something especially well adapted for a given function”, in much the same way I don’t have a problem with ‘belief’, in the context of “I have weighed up the evidence and my conclusion (belief) is that….”.

    *However*, I do accept that in the current climate you are asking for trouble if you use either word in a paper (especially in the title) and that it should be avoided if possible. Sad really, English is a wonderful language with huge numbers of words having multiple meanings, and it does scientisits a great disservice that we can be forced away from clear and useful language by the weasel-like activities of others.

  6. #6 Stewart Macdonald
    April 30, 2007

    I’ve got a male Brisbane river turtle (Emydura macquarii) who displays his organ if I hold him vertically. It freaked me out the first time he did it. I’ve got a photo here:

    http://www.flickr.com/photos/smacdonald/478106923/

    Stewart

  7. #7 Hai~Ren
    April 30, 2007

    Live uncensored turtle on turtle action! Oh my eyes how they burn.

    What gets me is the funny vocalisations the male turtles make while in the act. I never knew turtles could be so vocal until I entered the right search terms in YouTube, which is a testament to the number of people who happened to have a video camera at hand when the turtles were at it.

    So… who wins as a symbol of fertility and virility? The hare or the tortoise? =D

  8. #8 Michael P. Taylor
    April 30, 2007

    For what it’s worth, I personally prefer to restrict ‘penis’ to mammals.

    Is that a terminological preference, or a lifestyle choice?

    *rim-shot*

    (Sorry, but someone was going to make that rather obvious joke sooner or later, and I never have been able to pass up an inviting setup line.)

  9. #9 Bruce Mohn
    April 30, 2007

    Hi Darren:

    I’ve kept a variety of turtles, but have only seen penile/phallic displays in a leopard tortoise and Pelomedusa subrufa. The first time I saw the leopard tortoise presenting I thought he had prolapsed his cloaca. When he ejaculated, the mystery was cleared up. He displayed often the first year I had him and I suspect that may have been due to the antibiotic I was administering for a nasal infection.

    On the size issue, I think the explanation that makes sense to me is that they need an organ that large so that they can reach around the female’s shell and enter her. I’ve only seen box turtles (Terrapene carolina) mating (or trying as in that case the female had closed her shell up tight and was having none of it). But in that case, it definitely looked like the male needed sufficiently large equipment to consumate the act.

    As long as we’re talking about terrifying reptilian reproductive equipment, how about those of snakes? I found a roadkilled male milk snake once that had presented at death. I wasn’t aware that they actually have hooks on their phalluses, apparently modified scales. They work really well as while I was carrying it off the road, the hooks managed to snag on my pants and were a real pain to detach.

    Bruce

  10. #10 Dave Hone
    April 30, 2007

    Mike,

    I was going to make that joke, damn you. Still, at least someone did it….

  11. #11 Dr Vector
    April 30, 2007

    A few years ago I raised a snapping turtle (Chelydra serpentina) hatchling to adulthood. When he became sexually mature, he would extend his penis and hiss and snap when handled.

    The poor guy was pretty lonely. One night I came into the living room and caught him humping a rock. No kidding.

    And I once had a tennis shoe that was deflowered by a male three-toed box turtle (Terrapene carolina triunguis).

    From what I’ve read, this sort of thing is not that rare (in turtles, or just about anything else). Does anyone else have any tales of weird chelonian sex?

  12. #12 Chas S. Clifton
    April 30, 2007

    To the obvious comment list, will “hung like a turtle” ever enter popular discourse? It might be appropriate for certain political pundits, combining combative masculinity with a “hide from the contemporary world” outlook.

  13. #13 John H
    April 30, 2007

    Design isn’t an evil word. Intelligent designers and good old Rev Paley have just given it an evil taint. I say, don’t placidly hand over this word to them as “theirs” and hence anathema to good honest scientists.

    I refuse to surrender functional parts of the English language to IDiots or creationishts.

    Design is a perfectly useful (and short/parsimonious) term to use for “evolved architectural pattern,” “form-function complex,” or similar. Evolution, if viewed as a tinkering pattern and process, still produces designs (small ‘d’). Nothing wrong with saying that. There’s just no intelligent design/foresight/teleological-whizbang-magic-fairy-dust involved.

  14. #14 Darren Naish
    April 30, 2007

    Ok John, well said. However, I’m still not entirely happy, as inherent to most definitions of the word ‘design’ are notions of planning, preconception or intent… and is that how evolution works?

    For those of you who might not appreciate who ‘John H’ is, check out his publications here.

  15. #15 Zach Miller
    May 1, 2007

    Dr. Vector, your comment makes me both chuckle and whince.

  16. #16 Nick Pharris
    May 1, 2007

    Eesh, speaking of frightening reptile genitalia:

    http://www.livescience.com/animalworld/070430_duckgenital_evolution.html

    Also, regarding design, to me, used as a noun, it can just mean ‘layout’ or ‘pattern’, without any necessary implication of conscious planning having gone into it.

  17. #17 Alan Kellogg
    May 1, 2007

    A male turtle’s equipment ’tis schlong indeed.

  18. #18 Hootee McNee
    May 1, 2007

    *rim-shot*

    Whoah! Enough with the gay jokes already…

  19. #19 DianeAKelly
    May 1, 2007

    Obviously, I agree with John H. on the “use-of-the-word-design” controversy here. If we give up “design” just because the IDiots misuse it, we might as well give up the word “theory” too.

    >I’m still not entirely happy, as inherent to most definitions of the word ‘design’ are >notions of planning, preconception or intent… and is that how evolution works?

    I actually thought about this a great deal when I was writing the paper and finally settled on using the word because it implies that the anatomical arrangement of tissues in these animals didn’t appear randomly. The structures weren’t pre-planned by any intelligent entity, of course. But they did evolve, and evolution does work as a non-random filter of anatomical variation. And there just isn’t *room* for long, circuitous, lawyerlike language in a Biology Letters paper!

    As for restricting the word “penis” to mammals, I just don’t see why mammals deserve any special treatment here. If it’s a male copulatory organ that puts sperm into a female, it’s a penis in my book.

  20. #20 Matt Mullenix
    May 1, 2007

    “The turtles cannot sing, and yet they love;”

    John Dowlande

  21. #21 KAT
    May 2, 2007

    Here’s one of my California Desert Tortoises enjoying the favors of a chunk of concrete. http://www.flickr.com/photos/talleyjones/267354553/

  22. #22 Henry
    May 2, 2007

    Pardon my gall, but I’m pretty sure the following passage is in error:

    A pair of long retractor muscles extend for most of the length of the phallus’ dorsal surface, and attach within the body cavity to the lumbar vertebrae. When at rest, the phallus is actually doubled up on itself within the cloaca, and it is the contraction of the retractor muscles that causes the phallus to un-double and protrude (Gadow 1887).

    Since the retractor muscle’s origin is in the body and insertion is in the penis, shouldn’t muscle contraction result in retraction, rather than protrusion? It would also make sense, given the name.

  23. #23 John H
    May 2, 2007

    Duck genitalia! (free registration required) and here (w/ impressive pic of duck dangle-age)

  24. #24 Neil
    May 2, 2007

    Was looking a what palaeontology stories were on the net on Topix – paleontology news and you’ve been linked:
    see http://www.topix.net/science/paleontology

    just thought you’d wana know

  25. #25 Tribadaia
    May 3, 2007

    male intromittent organs therefore arose independently among tetrapods on more than one occasion

    I’ll just BET they did!

  26. #26 Simon Tonge
    May 3, 2007

    In another life I worked in the Herpetology Dept at the Durrell Wildlife Conservation Trust in Jersey and for many years worked with Geochelone radiata and Testudo marginata. Both these species are spectacularly endowed with large (c50% of plastron length), purple organs distended at the business end and with a spiky tip. Young adult male G.radiata regularly used to extrude their old chap and gave every appearance of enjoying rubbing it on clumps of grass, rocks etc. In my simple minded way I always assumed that the thing was so big because it had a long way to go and a couple of ‘U’ bends to pass before it could penetrate the lucky recipient. Several times I noticed male T. marginata being dragged around on their backs, and held in place only by their willies, by females that had obviously got bored with the whole process and unkindly moved off at a crucial moment. Eventually the organ would deflate and the spurned toroise would then flip himself over and rush round to the front of the female and give her a few bites on her forelegs to immobilise her before climbing on the back and resuming play. Incidentally, once or twice I had cause to lift recently mated female G.radiata and noticed a small purple organ with a short spiky tip protruding from the cloaca. My, admittedly inexpert, eye thought that these looked suspiciously like a clitoris, which begs a few questions as to just what a female tortoise might be getting from an encounter with a large purple organ. [You will no doubt have noticed that I have avoided using the terms penis or phallus in this post].

  27. #27 jurek
    May 4, 2007

    Phew!

    My male red-eared slider turtle had *it* length of half carapace and umbrella shaped – with thin stalk and broad, flat cap with serrated edge.

    It always puzzled me, why male turtle doesn’t faint when this organ (much larger than it’s head and presumably filled with blood) was extended?

    Might be a subject of research for you!

  28. #28 David Marjanovi?
    May 4, 2007

    [You will no doubt have noticed that I have avoided using the terms penis or phallus in this post.]

    Then why did you use “clitoris”? :-)

  29. #29 Eloise Mason
    May 5, 2007

    Honestly, ‘long and purple’ doesn’t really qualify for terrifying, in my book. Rattlesnake hemipenes, now THOSE are terrifying — they look like medieval weapons of war. :->

  30. #30 Darren Naish
    May 5, 2007

    Well, ok. It’s the ‘in a tortoise with a total length of 20 cm, the phallus might be 8 cm long’ thing that I most had in mind I suppose.

  31. #31 Marie
    May 8, 2007

    So, uh, if a Ninja Turtle had a penis proportional to their body size… I guess getting it on with a human may not be as plausible as I originally imagined it to be. Good to know.

  32. #32 Tommy Tyrberg
    May 8, 2007

    Well, the mammalian clitoris is homologous with the mammalian penis, so it seems reasonable that female turtles should have *something* homologous too.

    As for duck genitalia, they mean that ducks are the only birds for which rape is physically possible. Male ducks do tend to use the opportunity too.

  33. #33 Christopher Taylor
    May 15, 2007

    Harvestmen (Arachnida: Opiliones) (which are what I work on) have also developed an intromittent organ independently of mammals, as have many other invertebrates. In the case of harvestmen, the somewhat verbose “spermatopositor” has been suggested as an appropriate term, but the vast majority of workers (including myself) stick to using the term “penis”.
    Oh yes, and the plural of penis is “penes”.

  34. #34 katie
    May 26, 2007

    I spent some time working with Blanding’s turtles up here in Nova Scotia (they’re species at risk). All I can say is that they were even more well-endowed than those pictures, and they tended to let it all “hang out” every time you picked them up. I highly doubt it was an aggression thing–those were some of the most relaxed turtles I’ve ever seen.

  35. #35 Luna_the_cat
    June 5, 2007

    Marie, the fact that this was an issue for you disturbs me more than the original subject matter, by far.

    Now, if you’ll pardon me, I need to go scrub my brain with lye……

  36. #36 MR
    June 6, 2007

    “California Desert Tortoises enjoying the favors of a chunk of concrete.”

    … there are some things you never expect to hear and this thread is overflowing with them.

  37. #37 Organic Chemistry Help
    June 21, 2007

    Most impressed with the duck genetalia. I did not see in the post above what the evolutionary reasoning was for an “organ” that big.

  38. #38 Fishead
    July 24, 2007

    OK, just first hand, recent observation from a freaked-out, non-scientist tortoise care giver.
    I found this board while searching for an explaination to the horrific ‘display’ my desert tortoise performed yesterday.
    “He” is a captive bread and well loved/cared for tortoise btw…about 6-y/o, with a shell close to 8″ long.
    Yesterday, I looked out on the patio to see him basking…I noticed a large ‘flower like’ (the only way I can describe) shape behind him aiming toward the sky…approx 2.5″ diameter, with a central orafice, again it looked like a fleshy dark purple flower at first glance… I feed him lots of mixed leafy greens/fruit, and sometimes there is purplish lettuce mixed in, so at first I assumed it was a piece he had dragged along under his shell, and that my eyes where playing tricks on me…
    To my horror, as I stepped out on patio…being a social critter, he picked up and started toward me dragging it along behind him and I could see the full length/size of it…!!!

    Growing up we had another tortoise for close to 20 years, and I had never witnessed ANYTHING like this! Nor had I heard of anything like it, so naturally I freaked-out, and assumed he had somehow gotten his insides on the outside of his body!!! I was horrified and alarmed that this was very bad for our young “Gamera”!!! Then I recalled that I HAD read something of tortoises ‘absorbing’ or somehow taking up water/moisture via their anus? Not sure if there is any truth to this but I remembered reading it when researching hybernation once and remembered the recommendation to place in their water-dish once in a while during hybernation…anyway…
    He moved about a little and it sort of retracted a bit he pointed it down and ‘dabbed’ it a bit on the concrete, dripping a little clear fluid… I had about all I could stand, so I picked him up and placed him in his water dish. He sat a second and walked out and pulled all his equipment back inside where it belongs! LOL
    So…after my innitial horror and total lack of understanding of what I had witnessed (actually I am still a little skeeved by the experience) see him retract it back into himself I was (relatively) he was OK and this was a normal, if not completely disturbing bodily function for him, although I until now could not make heads-or-tails of the ‘apperatus’…to me this flower-like ‘thing’ with central opening (approx .75″) looked very much like ‘Female Equipment’ to me, all opened up and flattened out and yawning like that…(gag, cough, cough). If that wasn’t enough it was all attached to a very long stem/shaft, easily 4″ or more, definately half his body length or better!!
    Again, I had never seen/heard of anything like this, and by the perportions, also unknown to me I naturally assumed poor tortoise had shat his guts out to put it bluntly…Yikes!
    Okay, kinda got carried away here…It was traumatic only for a minute or two, then pure bewilderment set in for a while, of course “I gotta know” is my current focus…now if it wasn’t for the completely bizzare configuration of young Gamera’s junk, I might phase into a level amazement…even a little jealousy, but oh hell-no! What in the world!?!?!
    Some day when I heal from this, I may come arround to a morbid curiosity and see if I can locate a mate for him to see…what in Gods green earth this tortoise does with that thing!!!

  39. #39 Fishead
    July 26, 2007

    P.S.
    My formost regret (trust I have many from this ordeal), is that I did not have the where-with-all to take a picture when I had the chance…not understanding what I was seeing and all… Just as many of us do not have graphic images on hand of grizzly injuries our family or loved ones may have incurred. In the moment, you just don’t think to reach for the camera when someone you know is in midst of a medical emergency.
    However, now that I know…(although I hope to never see again no matter how wonderful our Gamera may be feeling) I will snap a shot or two and send them here. I’ll add that there are some ‘impressive’ displays of turtle endowment here, but my tortoise has a whole lot more going on that I’m not seeing depections of here, or have been able to find anywhere else on the Net.
    And no, thanks, but I’m not interested in any ideas on how to encourage him…sickos, LOL. Trust me when/if that day comes, you will all regret any harborings of curiosity.
    The horror, the horror…

  40. #40 RPManni
    August 28, 2007

    >RE: So, uh, if a Ninja Turtle had a penis proportional to their body size… I guess getting it on with a human may not be as plausible as I originally imagined it to be. Good to know.
    <<<<

    They’re mutants, they are probably fit for humans if they chose to mate with one. Almost too sad they don’t really exist. That’s be an interesting experience.

    My pair of Rhinoclemmys P. Manni are interesting. Their breeding behaviors are fun to watch. My male, Donatello…(hey he’s a wood turtle, they’re smart)..would approach, do his head swing bobbing thing, and act like he’s begging for nookie. He nips and will stand on her shell, on all fours and reach over and try to nip her face!
    I havent seen his penis (if it engorges, thats what it is! fooey on fancy scientific terms..) completely out but I’ve seen enough to tell how big it is. In all honestly, it’s impressive. Funny looking, but impressive. He wont expose himself with me just holding him; but my younger male Raph seems to not mind hanging low. The bum. I think turtles & torts are typical males who like to let it hang sometimes. Those boxies in the water, that’s nothing more than them relaxing a bit and cleaning themselves.

  41. #41 John
    February 3, 2008

    My 2 pound red eared slider has a significant problem when his organ comes out as what appears to be a large part of his intestine larger than a golf ball comes out as well. And he has a really tough time getting it back inside again. I’ve used really cold water, and bactraban when it became dried out and appearing to be infected. Any suggestions to provide him with some assistance would be appreciated.

  42. #42 Kathleen
    March 24, 2008

    I have a three-toed box turtle (Terrapene Carolina Triunguis) who is approximately 50 years old and he seems to display his organ while bathing at times. However one of his more annoying habits as he is allowed to walk about the house is sitting on one’s foot and displaying his organs. As he is quite light (approx. 300 grams) if you are wearing shoes you may not notice his presence and then when he is removed from your foot it takes him a fair amount of time to retract his organ…

    For John with the RES I would suggest placing the turtle in lukewarm water- we always try to have the water for these turtles at near room temperature… so about 20 degrees. The slightly warmer water may help the turtle relax, also leave the room for 20-30 minutes as at times turtles will get stressed out by human presence- I know the three-toed doesn’t like having an audience while bathing or eating but will actively seek out feet to sit on for warmth or otherwise…

  43. #43 diane
    April 29, 2008

    i came upon this sight while doing a google search about something i had seen in my turltes tank the other night. i was sure my turtle was just Grossly constipated until i realized what i was actually seeing and was very glad i didnt try to use a q-tip to wipe his poop away. anyhow my guy who is maybe 3″ in shell size across has a “friend” who is well over a ft in shell size. this monster “apparatus” appeared when he was being amorous towards his friend.

  44. #44 samantha
    May 5, 2008

    well we have a pet turtle now we found on the side of the road…. so how can we tell whether its male or female???

  45. #45 Sandra
    May 16, 2008

    My boyfriend was freaked out a couple of minutes ago. We thought our turtle pooka was a female but tonight he just saw a black big thing hanging out of Pooka’s tail. The turtle put its “thing” back in and its tail looked swollen. We thought it was going to lay eggs until i read all of this…. He is freaked out.

  46. #46 John & Darlene
    August 22, 2008

    My girlfriend kept noticing her sons turtle ‘Daisy Belle’ had this enormous black thing coming from her tail I thought ‘she’ might have been trying to lay eggs my girlfriend insisted it was a penis so we googled ‘sexual reproduction organs of the red eared slider turtle’ and there it was needless to say the turtle has been renamed and we no longer are looking for eggs.

  47. #47 natalie
    September 26, 2008

    i just saw the long black think coming out of my map turtle ( malcolms ) tail it was wierd … kind of like another leg but black and comeing out of the tail at first i thought he was having a humungous poop but then i found this forum and know its his penis :) he must be so proud … but how come hes doing it if hes alone in his tank? is it because we have another turtle thats in a seperate tank within his site . i wouldnt mind having baby turtles but if we ever put them in together they malcolm bites and mingnum hisses back at him …….. maybe mingnums a boy too?? how can i tell?
    natalie x

  48. #48 Alex
    October 2, 2008

    Hi i have a turtle the one with diamond shape shell. well he has a habit of climbing small things.i cant fing a female for him. the big question is what should i give him to eat. i have been given him cucmber though

  49. #49 Kim
    November 8, 2008

    I teach 4th grade science & have a whole mess of reptiles in the room. When our box turtle exposed himself for the first time, it was the students who noticed it. “Mrs. Harvey, Pumpkin is making a giant purple poop!” I had never seen this before, but I am a farm kid, so I told the kids I thought the turtle was flashing them his boy parts kind of like boy dogs do sometimes. Later that day, the turtle was burying himself in his substrate. One of my quiet little girls observed that obviously, Pumpkin was embarrassed that we had seen him naked, so he was hiding! The kids & the animals never cease to amaze me!

  50. #50 Matashiki
    January 3, 2009

    Just the other day I was freaked out by my terrapin with this black “thingy” hanging out from under it’s tail, I’ve never really end up having a name for it, due to the fact that I could never tell if it’s a male or a female. Makes us come to the point where the freaking out and black “thingy” confirms his gender….

    what comes to a surprise to me was that I also have another terrapin kept alongside the first……. and it decided that it’s meal wasn’t enough and chomped down on the first’s sexual organ…. causing much discomfort for me and the first…. it wasn’t a pretty sight but good thing the second decided to let go, with a small chunk of the organ in it’s mouth, just waiting to bite something else…. freaky….

    and for your information, i decided that they are not going to be together for a loooooong time, seperated them so that it doesn’t happen again….

    oh yes, the first terrapin doesn’t seem to want to retract his member….. always exposing it each and everytime…. WEIRD! anyone with a remedy? it still freaks me out when i clean up his tank…

  51. #51 David Wiegand
    January 24, 2009

    We have a young leopard tortoise, named leo, aproximately two and a half years old (6 inches long) and we recently noticed that a fleshy, pinkish, protrusion a couple inches long resembling a small tail with a quarter-sized “mexican sombrero” at the end. We looked up pictures of male leopard tortoise sex organs on the internet and we found that all were much more purple and none had the “sombrero.” Is our leopard tortoise a leo or a lea? We would apreciate if you could send us your official e-mail address so that we could send you a short video or photos of him so that you could help us identify le(o,a)’s origin.

  52. #52 ed
    February 27, 2009

    what does head bobbing mean when gently handling my red eared slider turtles, I have two of them and they both exhibit this reaction. My guess is that it is either sexual or a sign of contentment.

  53. #53 ummerzzzzz
    March 8, 2009

    awkward situation!

  54. #54 Laura
    March 20, 2009

    Hi! I have two captive bred ornate wood turtles each w/ carapaces about 6 inches long. I’ve had them since they were approx. 6-8 wks old (about 1.5 years now). They recently have been “displaying” what looks like a big purple flower when in the water. They don’t appear in distress, eat lettuce, carrot, strawberries every day. Right now they get egg whites,grouund lean chicken, turkey, beef every other day or so. The “flower” is easily retracted upon my approach, but looks all the world like an organ designed for absorbtion rather than secretion…I took one to the vet when it first happened, she (the vet0 was unable to sex the turtle, but recommended a diet w/ more leaves, carrot, and a vitamin e (basically) oil. Then the other turtle did it and my freind the turtle expert suggested the flower may actually be a penis. The turtles don’t “display” when the other is around. I’m worried and don’t have accessto a vet specializing in exotics…HELP!!

  55. #55 Yella Rose of Texas
    April 30, 2009

    Wooooah! I’m glad I found this site! I was ready to chuck TurtleTurtle aka Mr.T over the balcony… One too many sci-fi movies… at least now I know his “stuff” isnt a parasite or alien… LOL!

  56. #56 Stacey
    May 3, 2009

    Hi–Laura (message 54), I would betcha the ‘flower’ is actually your turtle’s sex organs. I recently had the same thing happen to me. I have had “Ellie”, a 3 toed box, for 12 years! A very effeminate, 14 year-old turtle who has had prolapse issues in the past freaked me out when this huge purple/plum/black thing came out of her backend! We have a great reptile vet who suggested we get pictures of the thing and bring them in with “Ellie” to get checked out. Turns out “Ellie” is actually “Elliot”. Also turns out that “Ellie” is turned on by lukewarm water and tends to regularly display his organ in his water dish.

  57. #57 Arella
    May 6, 2009

    I have a really short question, (that I hope someone to answer) What is average for the size of a painted sliders erect phallus?

  58. #58 SERERNITY
    June 3, 2009

    THATS NASTY BUT I NEED ALL INFORMATION ON TURTLES PLEASE!

  59. #59 amanda
    June 9, 2009

    that is discusting… you people are so mean to those poor turtles… grose…… but it kinda makes me horny

  60. #60 Greg
    June 25, 2009

    I have had several turtles over the years and never seen anything like that. Weird, but thanks for sharing.

  61. #61 Shelby
    July 11, 2009

    I just saw my male turtle’s.. you know.. yesterday! It’s called ‘fanning’ when he takes it out for display, and man, it freaked me out! But thanks for this article!

  62. #62 shirona
    July 31, 2009

    hey thanks for this i have had my turtle for nearly 3 years, he is about ten years old, (previously owned by friends of ours) in the last month or so i started noticing a long grey thing coming out from below his tail the first time i also thought it was a poo as others have said and my husband thought maybee a phantom egg laying, then when i t happened again n it went back in i thought it might be a penis after hours of googleing turtles i found this, thanks it was very helpful n confirmed “eltrut” is a male as my friends never really knew, i still dont know what kind he is just that he is a side-necked.

  63. #63 Karen Carcamo
    August 24, 2009

    Hi my name is karen and my floating turtle (male) takes out some black wiggly stuff out and im scared cuz i dont know wat it is and it doesnt look like any of the pics above…can u help me???

  64. #64 maryam
    September 1, 2009

    hi i think i juz got scared by the same thing…. juz needed to know when will this organ go back in!!!! coz its been like this for one full day ?????

  65. #65 Karen Carcamo
    September 8, 2009

    yes, sometimes it stays out for a while, my ale turtle seems to concentrate when he does this, its on and off, its really weaird becauseits allblack n wiggly, doesnt look like anything above can someone please help me???

  66. #66 Nancy Valladares
    January 5, 2010

    What if it doesnt look “like a Penis”, I just viewed all the photos and read your article. My Turtles “organ” or “penis” is a little thicker and it does look like an organ when coming out of the tale. I’m concerned that perhaps it is his inside oragans and not a penis. I dont know and I havent been able to snap a picture. My turtles name is Simon, and i am concerned. I have been viewing other sites, but yours seems more informed. If i manage to snap a shot I would love to show it to you.
    Thank you so much,
    Nancy

  67. #67 David Marjanović
    January 6, 2010

    I’m concerned that perhaps it is his inside oragans and not a penis.

    Right next to impossible.

  68. #68 ian
    January 17, 2010

    i think biologists should use the word “design”, but only in papers about animals with fantastic genitalia and/or sex lives. let the IDers know what kind of god they’re promoting.

  69. #69 Dean Robins
    February 1, 2010

    I was delighted to hear that it could not be my turtle internal organs as my fella has his “black web looking thing” hanging out and also what looks like internal organs also.
    I have seen the web shapped thing before but never the organ sack at the back. I will add a photo and hopefully people will tell me that this is normal enough. I am just worried that he might be in pain as out local vet doesn’t have a clue about such things.

    Thanks in advance.

    http://djdrobins.fileave.com/DSCF1026.JPG

  70. #70 Michael O. Erickson
    February 1, 2010

    Sure doesn’t look like a penis to me… Ouch. I hope someone can help you (and your turtle) out – I would, but I unfortunately don’t have any experience with such things.

  71. #71 Sven DiMilo
    February 3, 2010

    gah!!! ew!!!
    I’ve handled lots of red-eared sliders in my time and I’ve never seen anything like that.
    Please try to find a veterinarian with expertise in reptiles; if you live in the USA you can start here. Or google “veterinarian exotics *geographical area*” or something. That looks like a nasty hernia of some kind to me, but IANAV.

  72. #72 Dean
    February 4, 2010

    Thanks for the advice, i will have to track down a proper vet in this area, i live in Ireland (Rural Ireland) most of them only have clues about Cows, Horses, and Cat and Dogs – other then that they are fumpted. The swelling has gone down and he is shooting about the tank like nothing is wrong, but he still has a small bit hanging out. Will keep you informed.
    Thanks

  73. #73 sneha
    August 19, 2010

    this site saved me a head traum..i was so tensed when i saw my red ear slider and something wierd under him.i though it could possiblt be something bad.thanks god.

    ps ;so cute by the way

  74. #74 Avery
    October 27, 2010

    Wish I had found this site before I called the vet… My 4year old box turtle was REALLY enjoying his live feeder fish today… He was in the flat water dish that I had placed 6 feeder fish in and his back end would periodically rise up in the air and the above mentioned “flower thing” was coming out the back… and he was still snapping at fish… weird.

  75. #75 Juan Yu
    December 9, 2010

    There goes my my last bits of innocence towards these animals………

  76. #76 Bob Michaels
    December 9, 2010

    Nature has always favored the Big Penis premise.The female of any tetrapod will always choose The Biggest and the Brightest.

  77. #77 David Marjanović
    December 10, 2010

    Nature has always favored the Big Penis premise.The female of any tetrapod will always choose The Biggest and the Brightest.

    Elsewhere on ScienceBlogs, I’ve been told everything above 7 inches just hurts…

  78. #78 Anonymous
    January 13, 2011

    you suck

  79. #79 Suom Y. Nona
    January 13, 2011

    Thank you Brandy Rodriguez, you suck too.

  80. #80 vijinder
    May 8, 2011

    in case of anal prolapse of a turtle
    keep the turtle in a seperate vessel and then dissolve a alum in water and dip the tail of the turle in the alum water for 2-3 minutes twice a day and then wash the tail and put the turtle back.
    the prolapse will be fine within 2 days.

  81. #81 justin
    May 19, 2011

    this is a great place,.

  82. #82 jawid
    June 21, 2011

    hi,am an animal photographer in my country,just started. i know something on animals but i didnt expect that it would be that long !!

  83. #83 Liza
    July 29, 2011

    I lmfao on posts 31 & 35.
    I love the interwebs.

  84. #84 kyle
    August 1, 2011

    seems to me like that if anything the turtle has the largest shlong of any animal.

  85. #85 David Marjanović
    August 2, 2011

    I’m sure it differs between turtle species…!

    Many, perhaps all, duck species surpass these lengths, BTW.

  86. #86 Owlmirror
    August 2, 2011

    Many, perhaps all, duck species surpass these lengths, BTW.

    Now, hold on a minute there.

    All duck species have penes?

  87. #87 David Marjanović
    August 3, 2011

    Yes, of course.

    All bird species outside of Neoaves have penes. It just so happens that Neoaves contains the vast majority of extant species: all except those that belong to Galliformes, Anseriformes or Palaeognathae.

  88. #88 maarie
    August 4, 2011

    wow for one i never though there stuff would be in there tail and good god are they for reals that looks nasty i feel sorry for the female turtle that my boyfriend has
    .

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