Getting Down and Dirty with Lumbricus terrestris


While many think of earthworms solely as decomposers, most night crawlers, including Lumbricus terrestris, rely heavily on herbivory, but it doesn't just stop there. Earthworms are very un-fastidious eaters. In fact, these worms will eat just about any organic material. While taking a special liking to dead leaves and other dead plant material, they will also feed on dead animals, living plants, soil, and even animal droppings (Griffith et al. 2013). Though these organisms are not carnivores, they will even accidentally feed on tiny live animals that are present in the soil occasionally (Encyclopedia of Life 2013).

See No Food, Hear No Food, Eat No Food?

L. terrestris
, as well as all other earthworms, have neither eyes nor ears (Encyclopedia of Life 2013). Instead, they continuously move through the soil, taking in nutrients as they go while looking for other things to munch on with their specialized chemoreceptors (or sense organs) to help along the way (Annenberg Learner 2013). Thanks to their light receptors, earthworms have the ability to differentiate day from night. This factor is a major advantage for feeding because this species of worm is known to come to the surface in the safety of the night and pull leaves down into their burrows (Griffith et al. 2013).

The figure to the right is showing where sensory receptors are located in earth worms. In more detail, it also portrays the flow of impulses that are transmitted.

Beware of the Toothless Worm!

As seen in Peter Jackson's version of Skull Island in King Kong (2005), most of us have witnessed our biggest, irrational fear in similar cartoons and movies where a giant earthworm suddenly appears with jagged, menacing teeth with the ability to eat humans whole. However, earthworms actually have no teeth at all (Encyclopedia of Life 2013). Instead, they are able to consume their food by their muscular mouths. It is those mouths that take leaves the size of themselves and pull them down into their burrows (Griffith et al. 2013).

The front end of the worm, the prostomium (which is found just in front of the mouth), is firm and pointed, making it easy for them to push their way through the soil as they eat (Encyclopedia of Life 2013). Worms swallow pieces of dirt and decaying matter, which then passes through the pharynx (located in body segments one through six), then the esophagus (segments six through thirteen), and into the crop where the food is temporarily stored (Annenberg Learner 2013). The stomach of the worm, also referred to as the gizzard, is a very strong organ (Annenberg Learner 2013). It grinds up the food and then moves it to the intestine. The intestine, which extends over two-thirds of the worm's body length, is where the food is broken down into usable chemicals, which are then absorbed into the bloodstream (Encyclopedia of Life 2013). Leftover undigested organic matter and soil particles pass through the rectum in the form of castings, or simply put, worm poop. These castings are rich in nutrients, which is the reason why farmers and gardeners like to have many earthworms in their soil (Griffith et al. 2013).

Still can't picture just how strong this earthworm's mouth is? Look at a few short video clips of L. terrestris eating located here.

Ever wonder how earthworms breed? Find out how on the Reproduction page of this site!

Check out where we gathered our information from on our Reference page