All About Worms

“Arrow worms” is a common name that refers to the members of the phylum Chaetognatha. The term “arrow worms” is descriptive of these organisms’ appearance, which do indeed look a bit like arrows. This phylum is composed of predatory worms that live in marine environments. Many of these worms are types of plankton, which are broadly defined as drifting organisms that inhabit the pelagic zone of bodies of water. However, not all arrow worms are plankton, as many live in the benthic zone, which is the lowest level in a body of water. The pelagic zone where plankton are found, in contrast, is defined as any part of a body of water that is not near the shore or bottom.

Flatworms, sometimes spelled “flat worms” (in defiance of the standard spelling, we might add), are unsegmented, bilaterian (their bodies have bilateral symmetry), soft-bodied inveterate animals that belong to the phylum Platyhelminthes. They have no specialized respiratory or circulatory organs, and they lack a body cavity. Through the process of diffusion, their flattened bodies (hence the name “flatworms”) absorb oxygen and nutrients. Because of these biological features, flatworms are considered very simple animals.

A rather distressed reader wrote to us the other day about some worms he found on the bathroom floor. To his further chagrin and disgust (the word “yuck,” all letters capitalized, appeared twice in the reader’s email), he also found one of the worms in the basket of his dirty laundry. The worms are small, about one centimeter in length, and they are a clear brownish color. The worms also have several horizontal lines on their body. What are these small worms on the bathroom floor, and what can our reader do to get rid of them?