Crustacean pain is still a complicated issue, despite the headlines

The Nature News blog reports on a recent presentation by Robert Elwood given to the Behaviour 2013 conference about crustacean pain. The headline, as is often the case with headlines, paints a simple picture:

Experiments reveal that crabs and lobsters feel pain

So. We’re done here? Well, no. When you go to the text, you find a more nuanced comment from Elwood:

“Assessing pain is difficult, even within humans,” Elwood told the Newcastle meeting. But there is a “clear, long term motivational change [in these experiments] that is entirely consistent with the idea of pain”.

“Consistent with” is not “revealing.” There can be any large number of hypotheses that can be “consistent with” available evidence, especially when evidence is incomplete or in early stages. If you just had your everyday experience to go by, the sun rising in the East and setting in the West is “consistent with” the Sun going around the Earth (which it doesn’t). It’s also “consistent with” the Earth going around the Sun, and rotating on its axis all the while (which it does).

Elwood appears to have given a review talk of his existing papers on the subject. There are no new data or papers mentioned in the news article. This means that I don’t have to update my previous post on what we know, and don’t know, about crustacean pain. It’s a tricky, tricky subject, and I think it is far too early to call this one definitively yet. Yes, crustaceans may feel pain, but they might not.

This sort of press could have substantial implications for for policy:

Robert Hubrecht, deputy director of the Universities Federation for Animal Welfare (UFAW) and the organizer of the session at which Elwood gave his talk, says that the data for crustaceans appear equivalent to the kind of data that are used to give mice the benefit of the doubt, and thus award them protection from possible pain under the law.

I wonder if Hubrecht has seen any other data besides those generated by Elwood and colleagues. Has there been independent replications of many of these results?

It’s also worth thinking about the consequences if all crustaceans given the same protection as mice. Well, crustaceans are a far more diverse group of animals than mice. Daphnia and Artemia are crustaceans. Daphnia, for example, are barely visible to the naked eye and are used in huge numbers for water quality testing. Some crustacean researchers I’ve talked to dread the effects on those sorts of environmental monitoring efforts if suddenly, a blanket change on regulation to crustaceans were to drop in.

For that matter, why single out crustaceans as special concern? Why not insects, which have as good or better evidence for experiencing pain?

Full disclosure: I have co-authored research in the field of crustacean nociception, which was unable to replicate some early findings.

Additional: See also this post from Magnus Johnson, commenting on the paper that prompted my “What we know (and don’t)” post. I like this piece of writing:

I stand by my feeling that whether animals feel pain or not is irrelevant. To damage or stress a living organisms for no reason other than to enjoy their struggling and suffering is like taking a hammer to a Ferrari or slashing the Mona Lisa. It is an act of pure mindless vandalism.

More additional: Popular Science has picked up this story. This blog makes a cameo appearance in the article.

Additional, 8 August 2013: The Canadian edition of The Huffington Post picks up the story.

More additional, 8 August 2013: I looked at the abstract book for the Behaviour 2013 meeting that Elwood presented his talk at. It’s interesting only one that out of many symposium talks is getting coverage. In the abstract, Elwood puts forward a paper on prawns that was not replicated using three other decapod crustacean species.

Softpedia covers this story as being “as cited in Nature,” which kind of leaves out that this was a conference presentation, not a new paper in the journal.

ZME Science also reports on this Nature News piece.

Additional, 9 August 2013: Nature World News also covers this story. It’s a mash-up the Nature News article and a few other online essays and articles.

Related posts

What we know and don’t know about crustacean pain
Crustacean nociception: The worry
Ignorance may not be bliss, but perhaps it is painless
Do octopuses feel pain as deeply as mammals?
Squished squid, or: noci-ceph-tion

External links

Experiments reveal that crabs and lobsters feel pain
Do crabs feel pain?
Crabs And Lobsters Probably Do Feel Pain, According To New Experiments