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Friday, April 4, 2008

The Cephalopod Dating Game

I thought I would take a few minutes for a quick post as a way of hello and to say "Thanks Kevin!" But then I thought, I might as well start off on the right foot* with some cephalopod love. 

The recent  Abdopus aculeatus mating paper by Huffard et al. has been covered already in other quarters, and I won't rehash their coverage or the original press release, but there is new video available to go with it from two different sources, which I think is enough of an excuse for me to throw together a quick post highlighting not only this study but some of the other cool work Christine and her colleagues did on this species. But first the video...

A distinctly different video with Roy Caldwell narrating can be found on the Associated Press video site. Unfortunately they don't provide embedable video, but it's well worth the click (and waiting through their 15-30 second advert video).

Christine Huffard is now a Postdoc at MBARI and did her thesis on Abdopus aculeatus behavior and locomotion.  In the paper that was recently published online in Marine Biology, she and her colleagues described the complex mating behaviors of this species, information gleaned through over 790 hours of observation in the wild. Much has already been mentioned of the sneaker males,  males guarding female burrows, male aggression towards competitors, males ripping and tearing each other's hectocotylus arms (OUCH!).  

One thing I find especially interesting is that many of the behaviors noted in their study of this octopus have been noted in one or more species of squid or cuttlefish before. As the authors report, this species of octopus does not show any reason to be especially unique in mating behavior either, suggesting that other species of octopus may have similar behavior that has not yet been observed. 

In their 1996 book Cephalopod Behavior, Hanlon and Messenger were careful to point out that there were not many studies to base the chapter on, and especially lament the lack of knowledge in oceanic squid mating behavior.  Mating behavior in cephalopods was at that time represented primarily by a select few species: 15 species of squid, with only two well studied, 9 species of cuttlefish, again with only two species well studied, and 16 species of octopuses with laboratory studies of Octopus vulgaris comprising the bulk of the observations. Octopuses were viewed as solitary animals and octopus mating was interpreted as the last major act in life and one without any ritual or selectivity, or as Boyle and Rodhouse summarized in Cephalopods: Ecology and Fisheries -
Mating takes place with few preliminaries in octopuses, but in cuttlefish and loliginid squid , elaborate courtship behaviors have been described.
In the intervening 12 years many discoveries have changed the way cephalopod mating and subsequent parental care is understood, or at least viewed. Hunt and Seibel showed that Gonatus onyx, in contrast to all other known squid species, broods its eggs, caring for them for over a year before they hatched as the female literally wastes away, metabolizing her own muscles to stay alive.  Recent research by Hanlon et al. published in 2005 suggests that at least in one species of cuttlefish, Sepia apama, the females may "reward" sneaker males by choosing their spermatophores as the ones used to fertilize the eggs. Interestingly, the Huffard paper found that the length of single copulation time for a sneaker male was twice as long as for a guarding or transient male. So finally, we find an octopus species with what would traditionally be known as squid and cuttlefish-like agonistic behavior, complex mating rituals, guarding behavior and sneak attack/sexual mimicry. In just a dozen years, octopus mating has gone from a boring, post-climactic act to spicy, complex, and even intimate.

With hints of similar behavior in other octopus species (Octopus cyanea), there is now even more need to get some significant observation time in on at least the shallow water species. Christine and her colleague put in 790 animal observation hours watching 167 individuals(!!). Aside from the cephalopods, this study had the video technology working with video data recording, video analysis and illustrations pulled from video.  For me, adding in some diving (they had no need, as it was snorkel accessible intertidal areas) would make it a perfect study.


Huffard et al. Mating behavior of Abdopus aculeatus (d’Orbigny 1834) (Cephalopoda: Octopodidae) in the wild. Marine Biology (2008). Published online: 23 February 2008. 

Boyle, P.R.,  and P.G. Rodhouse. 2005. Cephalopods: Ecology and Fisheries. Blackwell, Oxford, UK

Hanlon et al. Transient sexual mimicry leads to fertilization. Nature (2005) vol. 433 pp. 212 

Hanlon, R.T. and J.B. Messenger. 1996. Cephalopod behavior. Cambridge University Press, New York, New York, USA.

*Huffard et al. Underwater Bipedal Locomotion by Octopuses in Disguise. Science (2005) vol. 307 pp. 1927.

Hunt, J.C. and B.A. Seibel. Life history of Gonatus onyx (Cephalopoda: Teuthoidea): ontogenetic changes in habitat, behavior and physiology. Marine Biology (2000) vol. 136 pp. 543-552.

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