I was listening to a podcast talking about the tortoise nicknamed “Lonesome George”. George, it seems, is the last of his kind. So there’s been attempts to mate George with females of a closely related species. George, however, isn’t interested. Researchers have tried to get George aroused in hopes that they could manually stimulate him enough to ejaculate so that they could try artificial insemination. This hasn’t worked, either.
What I don’t understand, though is there are devices made which you can hook up to a penis and they’ll cause the wearer to ejaculate. Why can’t they do the same thing for George? Is there’s something about reptiles which prevents this? (I know that they used this on a dead human, once, so I’d think that a giant turtle wouldn’t pose a technological problem.)
I can’t find any site which explains why milking Lonesome George hasn’t been done, but I can tell you a little bit about turtle reporduction that may help.
The penis in turtles resides inside of the tail. When turtles mate, the penis is everted through the cloaca, the all-purpose opening in the tail. This is accompanied by, and I think made possible by, engorgement which results in an erection. Tortoise tails are extremely muscular. Forcing the male to evert its penis without injury may be impossible. Performing any kind of milking operation without eversion is probably also impossible. To further complicate matters, reptiles are usually infertile unless certain seasonal conditions have naturally or artificially been met. Some reptiles will mate but not produce eggs or young unless they have experienced a period of cool temperatures. Some require a real or simulated rainy season. I found one site which indicated that Lonesome George has mated with several females already, but no eggs were produced.
When I was in college in San Diego, I had a friend who was a dolphin trainer at Sea World. She and the other dolphin trainers had to collect sperm from dolphins from time to time. This was a fairly easy thing to do because dolphins are social and horny creatures and, as was explained to me, clearly enjoyed the process.
One time a new female dolphin trainer had to perform the process for the first time and being inexperienced, missed the collection cup and got dolphin ejaculate all over her torso. It should go without saying that her nickname was Pearl for the rest of her employment.
Okay, now that I’m done making my little joke, I’ve got a serious question.
Why bother to make a female clone as a mating partner for LG? Sure, George may get his jollies in the long run, boinking a babe tortoise that’s, like, *90 years * younger than he is. (Go, George!) But is there any benefit to the gene pool? And once you can clone the guy, haven’t you already “saved the species”?
Making clones to perpetuate the species is going to be far more expensive than if you could produce a clutch of eggs and expand the population that way.
Manipulating the sex in a turtle is going to be much easier than in mammals because sex determination is not on the basis of sex chromosomes (X and Y) but rather depends on the temperature at which the embryo develops.