Christine Huffard sent me a note alerting me to the publication of her latest paper, and she thought I might be interested because I “seem to like cephalopods”. Hah. Well. I’ve noticed that Dr Huffard seems to have some small affection for the tentacled beasties herself.
The paper follows on an old tradition and an old problem. While people have no problem distinguishing human individuals, we have a tough time telling one individual animal from another. This perceptual difficulty complicates problems of studying variations in behavior or physiology, or monitoring numbers and behavior, in natural populations. One solution is tagging or marking the animals in some way, but that always has the risk of changing or harming the disturbed animals — non-invasive procedures are much preferred. This is an especially difficult problem with small animals, like zebrafish or small octopus; I’ve struggled myself with trying to track individual fish in experiments.
I came up with one solution, and Huffard et al. have come up with something similar: humans can be trained to recognize distinctive individual variations, and learn to identify single animals. In this paper, they describe a pattern of white pigmented regions that are consistent within single animals of the species Wunderpus photogenicus…and as you might guess, that is a great excuse to put together a collection of photographs of these aptly named animals.
You might think that animals with a reputation for dynamic camouflage, who can change their skin color and texture at will, might lack any patterns that remain constant. Not so! Cephalopod coloration is not infinitely plastic, so there are always shadows of the underlying biology that can be detected. This is especially true of animals that use distinctive markings, such as warning coloration, like the blue-ringed octopus.
The wunderpus has distinctive markings as well — they look like they belong in the 1960s, either as a tie-dyed t-shirt or better yet, a psychedelic concert poster — and as it turns out, they have characteristic individual white markings that can be easily distinguished. With a little practice, people can get good at recognizing individuals by spotting the spots.
Wunderpus is among the most sought after subjects for underwater photography, so this means that the tourist trade can be tapped into to provide data on the populations — all those tourist snaps can be used to record the existence of individuals over time. This is a great idea for monitoring populations. It also opens up another useful possibility: wunderpus is in high demand for private aquaria (at over $700 each!), so with a complete catalog of natural populations, it might well be possible to recognize illegally acquired animals. Look for wunderpus photos on milk cartons someday!
Meanwhile, you can browse the online database of Wunderpus photos, and if you’re diving in Indonesia, you can contribute to it, as well.
Huffard CL, Caldwell RL, DeLoach N, Gentry DW, Humann P, MacDonald B, Moore B, Ross R, Uno T, Wong S (2008) Individually Unique Body Color Patterns in Octopus (Wunderpus photogenicus) Allow for Photoidentification. PLoS One 3(11):e3732.