Earthworms may be good bait for fishing, but they also serve an important ecological purpose, and a fascinating new study explains their secret weapon.
Earthworms are well-known for munching on leaves and decaying organic material that rests on the forest floor. Many of these leaves come from plants that produce compounds that are toxic to most other herbivores, and scientists have struggled for years to figure out how the worms can eat such harmful chemicals.
According to a report from Livemint, however, they may have finally figured it out. Earthworms can generate special compounds in their guts to neutralize plant toxins designed specifically to keep would-be predators at bay.
The research, published in the journal Nature Communications, shows that earthworms possess special kind of metabolites in their gut, called “drilodefensins.” Scientists studied the earthworms’ digestive tracts with a molecular microscope to find out just how the slimy creatures handled the dangerous chemicals found in the plants that they ate.
Plants produce compounds called polyphenols, which serve as antioxidants and help make up the plants’ color. In certain plant species, they also act as a pesticide that keeps predators from eating away their leaves.
Earthworms are famous recyclers, and are known to decompose organic materials and return carbon stored in plant waste back into the soil. They serve an important purpose in many ecosystems where plants exist, but researchers have always wondered how they could digest the polyphenols found in plants’ leaves.
A team of scientists at the Imperial College of London found drilodefensins in the stomachs of 14 different species of earthworms, though the chemicals were not found in species related to the earthworms.
Earthworms help keep the circle of life spinning by cleaning up dead leaves on the ground and returning their nutrients back to the soil. Drilodefensins are the key to keeping the worms from poisoning themselves on their dead-leaf feast, and they are the very reason leaves don’t pile up feet from the ground every fall when the trees prepare for winter.