A snake that's as thin as a spaghetti noodle with a body small enough to rest comfortably on a U.S. quarter has just been identified as the world's smallest snake, according to a paper published today in the journal Zootaxa .
The newly identified species, Leptotyphlops carlae, measures just 3.9 inches long and was found under a rock on the western Atlantic island of Barbados. Two other extremely small snakes, L. bilineatus from Martinique and L. breuili from Saint Lucia, were identified nearby, suggesting that the world's three smallest snakes are all Caribbean threadsnakes.
Blair Hedges, who made the finds, told Discovery News that "determining the smallest (snake) is not simple."
Hedges, an evolutionary biologist at Penn State University, previously identified the world's smallest frog and lizard on Caribbean islands. He explained that the process of naming the smallest requires measuring adult individuals -- ideally at least one male and one female -- and then comparing the average size to all other known species.
He determined the Barbados threadsnake is the smallest of more than 3,100 known snakes. The snake may even be as miniscule as nature could go for snakes since, if it were any smaller, he believes its young would have nothing to eat. As it stands, Hedges thinks it primarily consumes the tiny larvae of termites and ants.
Females of this smallest species produce just one slender egg. In contrast to larger species that may lay up to 100 eggs in a single clutch, with each egg measuring just a fraction of the mother's body, this snake produces a single hatchling that is half its mother's size.
"The fact that tiny snakes produce only one massive egg -- relative to the size of the mother -- suggests that natural selection is trying to keep the size of hatchlings above a critical limit in order to survive," he explained.
Hedges added that, because of the snake's small size, "almost anything could be a predator, including centipedes and spiders."
Already the species appears to be in grave danger.
"My (two collected) animals were found next to a patch of forest, so I surmise that they require a forest (habitat) like most other native organisms," he said. "The islands were completely covered with forest originally, and now there is almost no forest remaining."
If Barbados residents continue to engage in habitat destruction by replacing forest lands with buildings and farms, the threadsnake could, he said, go extinct "because these animals live on islands, they have nowhere to go when they lose their habitat."
The island isolation likely explains many animal size extremes, both big and small, since species over time evolve to fill ecological niches unoccupied by other organisms. On land, for example, an insect might replace the smallest snake's spot in the food chain but, on water-surrounded Barbados, the snake evolved to fill that spot. Information on other snake size extremes may be found here.
Robert Henderson, curator of vertebrate zoology at the Milwaukee Public Museum, told Discovery News that he agrees with the findings, saying that "the West Indies harbor the smallest species of frog and lizard; may as well have the smallest snake too."
Herpetologist Robert Powell, who is a professor of biology at Avila College, also supports the new research.
"What I find most exciting is that we are seeing how nature pushes the lower size limits of body size," Powell told Discovery News. "I remember as a student being fascinated by the smallest known frog, lizard and snake -- marveling at how all of the necessary parts fit and worked."
"Since then," he added, "those size limits, which we then thought were immutable, have been extended again and again. Dr. Hedges seems to think that this time, nature has run up against a real wall, and that body size for a snake couldn't get any smaller, but I wouldn't bet against him finding a smaller species next year."
