hello,

I would like to show you some of my favorite worms if that is alright.

Classifying what worms are is best explained by stating what worms aren’t. Worms DO NOT have limbs, and I personally find that this is the easiest-to-obtain method of determining what is NOT a worm. So, for instance, Onychophora are NOT WORMS despite being colloquially known as “Velvet Worms”, Various larvae are also commonly referred to as worms due to their resemblance. Worms are not as closely related as say, beetles… which are a specific type of insect with a pair of shell-like outer wings (as well as the largest group of insects). Worms are bilateral (symmetrical) invertebrates with long tube-like bodies.

The origin of the term ‘worms’ comes from the now-outdated taxonomic term Vermes created by Swedish biologist Carl Linnaeus for all non-arthropod invertebrates. It was  later updated by French biologist Jean-Baptiste Lamarck, to be named after the mythical Wyrms, wingless lizard-like dragons, before which worms were considered reptiles.

The three largest groups of worms are:

Annelids, including earthworms, marine worms AKA polychaetes, leeches, and ragworms are a varied phylum. Their defining characteristics are their segmented bodies, soft exteriors, and status as coelomates (have a body cavity).

Platyhelminthes, commonly known as flatworms, are acoelomates (have no body cavity), they have no respiratory organs, instead gaining oxygen and other necessary nutrients via diffusion, absorbing what they need from the world around them.

Nematodes are a phylum of worms that survive off of microorganisms, some of them are known for being parasitic (helminths). Nematodes also have a similar phylum, Nematomorpha which are parasitic worms colloquially known as Horsehair worms.

I’m sorry because this is about to change from a simple explanation of worms into a simple ode to these beings we’re lucky to share a planet with.

Worms, my beloved 

Worms, segmented

Under ground and sea

From Hurun to Nadi

Helminths seeding

Lumbricidae feeding

Similar yet varied

All around you and me