Reptiles
Barbados Threadsnake
Tetracheilostoma carlae · also called barbados threadsnake
The Barbados threadsnake is the smallest snake known to science: a fully grown adult is about 10 centimetres long and as thin as a strand of spaghetti. It lives buried in the soil of the last wooded patches of a single Caribbean island, eats ant and termite grubs, and lays one enormous egg.
Overview
The Barbados threadsnake is endemic to Barbados, apparently confined to the small amount of forest and secondary woodland left on the island. Adults are about 10 cm long and only 2 mm thick — small enough to coil up on a coin. It belongs to the threadsnakes, a family of blind, worm-like burrowers with smooth scales and eyes reduced to dark spots.
A recent discovery
The species was recognised as distinct and named in 2008 by the herpetologist S. Blair Hedges, and named for his colleague Carla Ann Hass.
One giant egg
The female lays just a single, greatly elongated egg, and the hatchling emerges at about half the mother’s length. This is thought to reflect a hard limit: below roughly this size, a hatchling snake would be too small to catch even the tiniest available prey, so the Barbados threadsnake sits close to the smallest a snake can be.
Mistaken identity
With its thread-like body and burrowing habit it is often taken for an earthworm, and it can be confused with the widespread introduced Brahminy blindsnake.
Status
The Barbados threadsnake is Critically Endangered. Barbados has been almost entirely cleared for agriculture and development, leaving a soil-dwelling woodland snake with very little habitat. It has been found at only a handful of sites, and some researchers fear it could be lost before much is learned about it.
Barbados Threadsnake: common questions
Is the Barbados threadsnake really the smallest snake in the world?
It is the smallest snake known to science. Adults measure about 10 centimetres in total length and are only around 2 millimetres across, so an adult can curl up on a coin. The next smallest snakes, other threadsnakes from the Caribbean and elsewhere, are only slightly larger. Herpetologists think the Barbados threadsnake is close to the smallest a snake can practically be, because a hatchling any smaller would struggle to find prey small enough to eat, and the female already invests everything in producing one unusually large egg and hatchling rather than a normal clutch of several.
How does such a tiny snake feed?
It specialises on the softest, smallest food available underground, mainly the larvae and eggs of ants and termites. It moves through the galleries of insect nests and through loose soil, and it takes prey using a small mouth and a feeding action suited to soft-bodied items rather than the wide gape and constriction or venom used by larger snakes. Threadsnakes in general are ant and termite specialists, and some are known to release chemicals that calm the insects or mask the snake's scent so it can feed inside a nest without being swarmed.
Is the Barbados threadsnake dangerous?
Not at all. It has no venom, its mouth is far too small to bite a person, and it is a secretive burrower that most people on Barbados will never see. Its defensive options amount to wriggling away into the soil, pressing its blunt tail against an attacker, and possibly smearing itself with cloacal fluid. It poses no threat to humans, pets, or crops. The conservation concern is entirely about the threat that habitat loss on a small, heavily developed island poses to the snake.
Why is it endangered?
Barbados is a small island that has been almost entirely cleared, first for sugar cane and later for housing, tourism, and other development, so very little of its original forest remains. A snake that lives only in soil and leaf litter within wooded habitat has correspondingly little space left, and it has been recorded from only a few small sites. With such a restricted and fragmented distribution, a tiny population, and continued pressure on the last patches of habitat, the species is listed as Critically Endangered, and some researchers fear it could be lost before much is even learned about it.