AMHERST, Mass. - Although large snakes often fascinate people with their ability to swallow prey many times their size, the snakes' diminutive relatives, threadsnakes, have a unique feeding mechanism which may be equally important, according to University of Massachusetts biologists. The study which details the findings is published by organismic and evolutionary biology doctoral candidate Nate Kley and UMass faculty member Elizabeth Brainerd in the Nov. 25 issue of the journal Nature.
"Typically when we think of snakes feeding, we think of pythons and boas eating large animals," said Kley. The snakes are able to do this because they have very flexible hinged jaws. Most snakes savor their infrequent feasts, taking anywhere from several minutes to several hours to consume a meal.
But threadsnakes, which measure just six to eight inches long and weigh in at roughly one gram, survive largely on the pupae and larvae of ants. "The only place you can find huge numbers of these are in ant nests," pointed out Kley, "so they search them out and rob the nest." Unlike their snake cousins, threadsnakes are chowhounds, tucking into meals at a rapid rate, with three or four bites each second. The front part of the triple-jointed lower jaws of these snakes swings in and out of the mouth "like a pair of saloon doors" in order to drag prey quickly into the esophagus, Kley said. The threadsnakes are the only vertebrates that scientists know of that use just their lower jaw to devour prey.
This rapid-fire eating pattern may have arisen due to the threadsnakes' hazardous foraging strategy, Kley and Brainerd suggest. When they invade ants' nests to find sufficient food, they have to eat very quickly to avoid being attacked, and even killed, by the large and powerful worker ants guarding the nests.
Very little research has previously been done on threadsnakes, partly because their small size makes them difficult to work with. Also, their tendency for burrowing makes them extremely difficult to find, Kley said.
Nate Kley can be reached at 413-545-1863 or kley@bio.umass.edu
Journal
Nature