Photo: Scientists discover world's smallest snake species
Jeremy Hance, mongabay.com
August 3, 2008
The species was discovered by Dr. Blair Hedges on the island of Barbados. Hedges has a fondness for miniature species as he and his colleagues also discovered the world's smallest frog Eleutherodactylus iberia from Cuba and the smallest lizard Sphaerodactylus ariasae from a small island off the Dominican Republic.
The world's smallest species—as well as sometime its largest—are often found on islands. In a small enclosed ecosystem species evolve to fit a particular niche, and sometimes this means an elephant shrinking to miniature size or a rodent becoming huge.
The snake named Leptotyphlops carlae, as thin as a spaghetti noodle, is resting on a US quarter. Blair Hedges, professor of biology at Penn State University, discovered the species and determined that it is the smallest of the more than 3,100 known snake species.Credit: Blair Hedges, Penn State
"If a tiny snake were to have two offspring, each egg could occupy only half the space that is devoted to reproduction within its body. But then each of the two hatchlings would be half the normal size, perhaps too small to function as a snake or in the environment," said Hedges. "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."
What is that critical limit? Food, says Hedges. The baby snake has to be large enough to be able to consume a ready supply of food. Leptotyphlops carlae probably feeds on ant and termite larvae.
The smallest animals have young that are proportionately enormous relative to the adults. The figure shows that hatchlings of the smallest snakes are one-half the length of an adult, whereas the hatchlings of the largest snakes are only one-tenth the length of an adult. Tiny snakes produce only one massive egg -- relative to the size of the mother -- which suggests that natural selection is trying to keep the size of hatchlings above a critical limit in order for them to survive. Credit: Blair Hedges lab, Penn State
"Habitat destruction is a major threat to biodiversity throughout the world," he said. "The Caribbean is particularly vulnerable because it contains an unusually high percentage of endangered species and, because these animals live on islands, they have nowhere to go when they lose their habitat." Barbados has already lost a number of its endemic species and some of those that remain are threatened due to habitat destruction and invasive species, such as rats, dogs, pigs, and cats.
Over 65 reptiles and amphibians have been discovered by Hedges and his team in the Caribbean. The paper describing Leptotyphlops carlae—to be published in the August 4th issue of Zootaxa—includes another new threadsnake species found on St. Lucia. This snake is only slightly larger than the world's smallest.