Friday Weird Science: A Dolphin Gets 'Spontaneous'

Sep 06 2013 Published by under Friday Weird Science, Uncategorized

Do you ever wish that you were more like a dolphin? More playful, carefree? More, you know, spontaneous?



I guess that depends on what you mean by "spontaneous". Aside from the many interesting habits of dolphins (spoiler, dolphins can be raging jerks, and they, and their good looks are the primary reason Lisa Frank exists. Which, I must say, makes them a jerk in my book), it turns out that dolphins can be particularly spontaneous in one, special way.


Morisaka et al. "Spontaneous Ejaculation in a Wild Indo-Pacific Bottlenose Dolphin (Tursiops aduncus)" PLoS ONE, 2013.

(Note: Today's Friday Weird Science is courtesy of David Schiffman, of Southern Fried Science. So if you find what you are about to see disturbing/gross, blame it all on him.)

(Another Note: What you are about to see may be disturbing/gross.)

Dolphins are some sexy creatures. Not sexy like this:


But sexy because they really like sex. More than humans. More than bonobos. In fact, dolphins are so sex talented that they have mastered what millions of teenage boys have been unable to achieve. Dolphins can masturbate. With no hands (it mostly involves rubbing against things).

However, just because they masturbate does not mean they ejaculate. Many animals are capable of masturbation that generally do not end up ejaculating, such as horses.

But what about spontaneous ejaculation? Spontaneous ejaculation is generally defined as being ejaculation (sperm and the stuff that goes with it) in the ABSENCE of apparently sexual stimulation (whether the animals who do this are thinking sexy, sexy thoughts, we may never know). It's been observed in horses, rats, mice, cats, dogs hyenas, humans, etc. But it has never been observed in dolphins.

Until now.

The authors of this study were observing the behavior of a group of wild Indo-Pacific bottlenose dolphins off the coast of Japan. It was a nice, warm day in July (it was also, rather oddly, this author's birthday. I feel really weird about that). The researchers and four sightseers (poor, soon-to-be-scarred-for-life individuals) were observing dolphins underwater.

Dolphin number 266 (aka, the perpetrator), was swimming with one eye open, just hangin'. Basically half asleep. Suddenly, both eyes opened, and...

Screen shot 2013-09-05 at 11.28.27 PM


And there it goes. The top panel, you can see the dolphin's penis with a little cloud coming out. That is what you think it is. Bottom panel is the flip of the tail that the researchers describe as "stretched his peduncle muscle upward", but kind of looks like "yeah, I did that."

If you want to see it in action? Well, yes, there is video (about 3/4 down the screen). I was kind of hoping for a triumphant little "EeeEEE" noise. No such luck.

Now I'm sure you must be wondering: why does this happen? It actually has to do with how ejaculation is controlled in the male mammal. This hasn't been tested, but the hypothesis is that if the dolphin is "wired" like some mammals such as rats (and there's no reason to believe he's not, in this case), ejaculation is controlled at the spinal level, rather than in the brain, and controlled by the release of various chemicals. During sleepiness (which you can often detect in a dolphin due to one eye being closed, as in this case), this system would be relaxed, and spontaneous ejaculation would be more likely. Of course, as Bjorn Brembs points out in the comments, it could also be that for dolphins, dreams are always wet. 🙂

And they do think it was spontaneous. The dolphins was just drifting, not rubbing up against things as they do when they masturbate. It appears the dolphin WAS just being spontaneous. I guess we could all use some spontaneity in our lives, but...maybe not this kind.



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