Nematalycidae are more closely linked to sandy soils, so Bolton was surprised to find the species in a clay-like patch of earth and he thinks digging 50 centimeters down was key to locating the mysterious creatures.
He couldn't learn all the details of his campus find until a year later, when he was able to examine the discovery in a low-temperature scanning electron microscope (LT-SEM) run by the U.S. Department of Agriculture in Maryland.
Under the LT-SEM, Bolton obtained high-resolution images of these tiny creatures and marvelled at the machinery of their mouths. Structures called rutella, which typically function in a similar way to teeth in other mites, instead support a pouch-like vessel in the front of the mouth. Bolton's theory is that the pouch acts like a nutcracker, holding microorganisms in place while internal pincers puncture the organisms and suck up their fluid contents.
Imaging mites of this size and body type require cold-temperature scanning so they aren't crushed by the intense vacuum effect of a normal electron microscope. Bolton and his co-authors froze the living mites in liquid nitrogen immediately upon collecting them, allowing for images of the mites just as they appeared in their natural habitat.
And though its movement and muscle pattern along the length of its body does resemble a worm's, the mite cannot alter its diameter in the way a worm can.
With an external surface resembling abacus beads, these mites "are like miniature accordions," Bolton said. "It's a case of convergent evolution they have the same basic way of moving as worms, insofar as their cuticle extends and contracts, but they also have legs and, to some extent, still use them. The worm-like motion helps them move around through tight spaces."
As far as evolution goes, the Nematalycidae branch off of the tree of life from ancient groups of mites whose fossils date
|Contact: Samuel Bolton|
Ohio State University