Red Earthworm, Lumbricus rubellus

The red earthworm (Lumbricus rubellus) is a species of earthworm that is classified within the Annelida phylum. It is native to the British Isles and Europe, but has traveled across the world to areas with appropriate habitats. This worm prefers to reside in soil that contains high organic matter content, like feces, but it needs loose soils in order to move about and feed. The sustainability of a habitat depends upon factors such as the PH balance of the soil, moisture levels, temperature, and the amount of light in the area.

The red earthworm can reach an average body length between .98 and 4.1 inches and is typically smooth and red in color. Its body is visibly segmented into 95 to 105 areas, with each segment holding four pairs of bristles or setae. These segments help identify the Phylum and Class of the species, but the permanent gonads that each worm bears can also help distinguish it from other worms. The sensory organs of the worm are located on the front part of its body. These organs, which contain chemoreceptors, are sensitive to alkaloids, acids, and polyphenols. The worm reacts negatively to specific levels of acids and alkaloids, but can identify food sources by sensing polyphenols. Similar chemoreceptors are located along the entire body and help the worm avoid undesirable soil and locate food.

The red earthworm is important to ecosystems across its range due to its preference for decaying food sources. When the worm consumes its food, it converts the energy of photosynthetic plants into food for animals that require higher nutrition values. This worm increases the number of bacteria and actinomycetes, which create the vitamin B12, and this increases the yield of barley fields. The red earthworm has been used in traditional Chinese medicinal practices to heal blood, rheumatic, and phlegm disorders in the preparation ritual known as Di Long.

Image Caption: Lumbricus rubellus. Picture taken in Commanster, Belgian High Ardennes. Credit: James Lindsey’s Ecology of Commanster Site/Wikipedia (CC BY-SA 2.5)