Opening a Can of Earthworms Trivia Quiz

Answer: False

Not only is there more than one species of earthworm, but earthworms (along with ragworms and leeches) have their own phylum: Annelida. There are several thousand species of earthworms. Although there are differences between the various earthworm species, there are also a number of similarities, including a body structure described as a tube within a tube.

Answer: True

That's right--an earthworm does not have a lung. Instead, respiration occurs directly through the skin. Earthworms, however, do have a circulatory system and blood that carries oxygen (which, like other animals, earthworms need to survive) to different parts of the body.

Answer: True

Earthworms come in a variety of sizes. Some are as small as one inch (25 mm) long. The common earthworm (Lumbricus terrestris) is typically slightly longer than a foot (30.5 cm) long as an adult. Specimens of the largest earthworm species, the Mekong giant earthworm (Amynthas mekongianus), have been observed, though, that are ten feet (three meters) long.

This species of earthworm is found in southeast Asia.

Answer: False

While an earthworm does have a brain of sorts or, at least, a central nervous system, it is not particularly large. The earthworm's intestine actually runs the length of the majority of of its body. It is part of the earthworm's digestive system that also includes an esophagus, crop, and gizzard.

Answer: True

Earthworms are hermaphrodites, which means they have both male and female sexual organs. The most common way that earthworms reproduce, however, is that two earthworms will mate, with each releasing sperm to fertilize the other's eggs. The earthworms will lay the eggs into a cocoon like structure. About three weeks later, young earthworms will hatch.

Answer: False

The earthworm has both a mouth (at one end) and an anus (at the other end). The mouth is partially covered by the prostomium, a fleshy lump that contains a number of the earthworm's sense organs. The slit like anus is found in a earthworm segment called the periproct. The exterior body of the earthworm is made up of a number of segments which remains constant throughout its life.

Answer: False

Earthworms really don't have eyes the way we think of them. They do have some photosensitive cells (can sense light) on their sides and back, mostly in the first few segments. In addition, their buccai receptor senses taste and smell. The epidermal receptor handles changes in temperature and chemical stimuli.

Answer: True

The earthworm does not have a skeleton the way we think about it. As previously stated, the structure of the earthworm has been described as a tube within a tube with fluid between the two layers. This is considered to be a hydrostatic skeleton.

Answer: False

Generally speaking the first segment (where the mouth is found) and the final segment (where the anus is located) are the only segments that don't have the bristle-like setae. All other segments do. The setae aid in moving the earthworm through the soil it may travel through.

They also have some tactile functions. Setae are not unique to earthworms, but can be found on a number of other organisms.

Answer: True

Under perfect circumstances, earthworms can live from four to eight years. In average circumstances, the typical earthworm can live for one or two years. The typical earthworm reaches full size in about one year. At birth, earthworms are fully formed, except for the sex organs which mature at about two to three months.