Wrangell Island, Yunshookuh Loop Campground, Wrangell County, Alaska, USA
May 9, 2011
Size: 2.5 mm
I found this tiny 'bug' crawling in my sifted moss sample while looking for spiders. It moved like a millipede, head and legs millipede-like, but didn't look like any I had ever seen, so I sent these photos to Dr. Derek Sikes, Univ. Alaska, Fairbanks, who forwarded them to Dr. Rowland Shelley, North Carolina State Museum of Natural Sciences, who sent the following reply:
"Derek: It is a milliped, a representative of the “other” subclass, Penicillata (one order, Polyxenida), commonly known as “pin-cushion millipeds.” They have soft, uncalcified exoskeletons; the body is covered with tufts of modified setae that Tom Eisner has shown, at least the caudal tufts of setae, are “autotomized” to entangle ants and other predators; and there is no contact between sexes in reproduction. Hence, they are totally unlike the hard-bodied, heavily sclerotized, worm-like millipeds that people are familiar with. This constitutes only the second record of the genus Polyxenus, the order Polyxenida, and the subclass Penicillata from Alaska, the other locality being Haines (See Shelley & Golovatch 2011, fig. ?4). I would identify the species as Polyxenus lagurus (L., 1758), but I’m not really certain, as these are different millipeds, and only a French lady and an Australian lady really known anything significant about them."
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