An article to be published later this month (Zootaxa; August, 2008) will announce that a newly described Thread Snake from the Caribbean island of Barbados is the smallest of the world’s 3,100+ snake species. The Barbados Thread Snake grows to a mere 4 inches in length, is no thicker than a strand of spaghetti, and can coil comfortably atop a quarter. It subsists largely upon ant and termite larvae, and may be threatened by habitat loss. A relatively large hatchling – ½ of the adult size – emerges from the single egg laid by the female (perhaps there is no prey species tiny enough to support a larger brood of smaller-sized young).
A related snake, nearly as tiny, has been discovered on nearby St. Lucia. Two snakes within the genus dwell in the southwestern USA – the other 103 species are found in Mexico, Central and South America, the Caribbean, Africa, India and Pakistan.
The Penn State biologist who discovered the snake, Blair Hedges, seems to have a quite a flair for his work – he and his colleagues have named 65 new amphibian and reptile species on Caribbean islands, including the world’s smallest lizard and smallest frog.
Islands and other isolated habitats are often home to the largest (Komodo Dragons, Aldabra and Galapagos Tortoises) and smallest animals within a group. Islands are difficult for many animals to reach, so those that do arrive often evolve into a variety of forms (and, eventually, species) to fill the many empty niches (specialized roles within a habitat) – in fact, Darwin’s theory of evolution was sparked by his observations of this process among finches on the Galapagos Islands. Caribbean Thread Snakes, Australia’s monitor lizards and the African Rift Lake cichlids are likely examples of this phenomenon.
You can read more about other species of Thread Snakes at: