What the heck is a worm?

Question

Is it an amphibian? Or an insect? Or something else?

Answer 1

It's an imprecise designation.

You've got your roundworms [nematodes], flatworms [Platyhelminthes], segmented worms [annelids], your spiny-crowned worms [Kinorhyncha], velvet worms [Onychophora] which are not really worms but are called worms; ribbon worms [Nemertea], and numerous other long thin invertebrates.  Not to mention the larval forms of some Insects are also called worms; caterpillars, maggots, cutworms, mealworms, and such.

LOL I forgot to mention ringworm which isn't even in the animal kingdom, it's a fungal infection!

So it depends on how you define your terms.

Answer 2

a worm is an invertebrate...

a cute little creature with no backbone.

its a class of its own...

insects ALL have a head body and 6 legs, and an exoskeleton

amphibians have a backbone and a brain

worms... well they dont have a hard exoskeleton nor do the have a backbone

so a worm is not an insect nor is it an amphibian its an invertebrate

Answer 3

insect

A worm is a common name given to a diverse group of invertebrate animals that have a long, soft body and no legs. There are about 4,400 species of worms, 2,700 of these are earthworms. Animals which are commonly called worms include species of annelids, insects (their immature larva stage), and flatworms. Many marine and freshwater species, which are usually seen only by professional biologists, are recognized as "worms".

Answer 4

In everyday language, the term worm is also applied to various other living forms such as larvae, insects, centipedes, shipworms (teredo worms), or even some vertebrates (creatures with a backbone) such as blindworms and caecilians. Worms can be divided into several groups,

    * The first of these includes the flatworms. This phylum is called Platyhelminthes. They have a flat, ribbon- or leaf-shaped body with a pair of eyes at the front. Some are parasites.

    * The second group contains the threadworms, roundworms, and hookworms. This phylum is called Nemotoda. Threadworms may be microscopic, such as the vinegar eelworm, or more than 1 meter (3 feet) long. They are found in damp earth, moss, decaying substances, fresh water, or salt water. Some roundworms are also parasites. The Guinea worm, for example, gets under the skin of the feet and legs of people living in tropical countries.

    * The third group consists of the segmented worms, with bodies divided into segments, or rings. This phylum is called Annelida. Among these are the earthworms and the bristle worms of the sea.

There are hundreds of thousands of species that live in a wide variety of habitats other than soil. Over time this broad definition narrowed to the modern definition, although this still includes several different animal groups. Major phyla that include worms include:

    * Acanthocephala (spiny-headed worms)

    * Annelida (segmented worms)

    * Chaetognatha (arrow worms)

    * Gnathostomulid (jaw worms)

    * Hemichordata (acorn/tongue worms)

    * Nematoda (roundworms)

    * Nematomorpha (horsehair worms)

    * Nemertea (ribbonworms)

    * Onychophora (velvet worms)

    * Phoronida (horseshoe worms)

    * Platyhelminthes (flatworms)

    * Priapulida (phallus worms)

    * Sipuncula (peanut worms)

The most common worm is the earthworm, a member of phylum Annelida. Earthworms in general have been around for 120 million years, evolving during the time of the dinosaurs. They enrich and aerate the soil; Charles Darwin found that worms turn over the top six inches (15 cm) of topsoil every 20 years. They lack a brain but have nerve centers (called ganglia); they also lack eyes but can sense light with photoreceptors. Worms are hermaphrodites (both sexes in one animal) but can cross fertilize.

Other invertebrate groups may be called worms, especially colloquially. In particular, many unrelated insect larvae are called "worms", such as the railroad worm, woodworm, glowworm, bloodworm, inchworm, mealworm, or silkworm.

Worms may also be called helminths, particularly in medical terminology when referring to parasitic worms, especially the Nematoda (roundworms) and Cestoda (tapeworms). Hence "helminthology" is the study of parasitic worms. When an animal, such as a dog, is said to "have worms", it means that it is infested with parasitic worms, typically roundworms or tapeworms.

"Ringworm" is not a worm at all, but a skin fungus.