The Difference Between a Nightcrawler & Bloodworm

Earthworms, also known as nightcrawlers, are extremely helpful in digesting and processing organic materials in the earth. Their digestion of plant waste converts rotting organisms into rich topsoil. Different types of bloodworms are thought to serve different purposes. Some are thought to digest organic waste while others have the structure of a predator.

  1. Appearance

    • Most bloodworms have four jaws on the front of their head with an eversible, or inside-out, proboscis between the jaws and the antennae. At the tail end of the bloodworm, there are two branchiae and a ventral cirrus that help it move and navigate.

      It can be difficult to determine which side is which on a nightcrawler as both appear smooth and rounded. They range from 2.5 to 15-centimeters with a clitellum, or a glandular organ, around the middle part of the body.

    Habitat

    • Bloodworms are generally found at all water depths to 1,312-feet. They reside in the region along the Atlantic coast from the Gulf of St. Lawrence in Canada to Florida. These creatures have also been found in the Gulf of Mexico and down the west coast from Mazatlan, Mexico, to central California.

      Nightcrawlers appear around the United States in any place that maintains moist soil that is "loose enough to burrow through and with sufficient organic matter," according to North Carolina State University's Integrated Pest Management Program.

    Biological Facts

    • Bloodworms usually reproduce from mid-May to early June in the most northern regions of their habitat. They reproduce in the late-spring to early-fall farther south. Bloodworms get their name because they have no circulatory system. Hemoglobin simply exists in the cells of the body cavity.

      Nightcrawlers are hermaphroditic and homosexual, but only one gender can function at a time. In order to reproduce, males exchange sperm, and the sperm enters the eggs when the worm changes into a female.

    Ecological Role

    • Bloodworms resist eating dead material or waste, and prefer to pursue live prey. Some studies show that bloodworms help control the population of sandworms. Bloodworms also serve as food for striped bass and sand shrimp.

      Nightcrawlers provide a vital function for the decomposition of organic matter and processing of soil. They also help by burrowing and aerating the soil. These small burrows in the ground allow water to more easily permeate the earth to reach plant roots.