A cricket’s entire life is in your backyard. Just like you might spend your entire life living in a single state, a bee’s entire world is the general area around it’s hive. These are all small creatures we don’t even think about,these are tiny little creatures that we barely pay any mind to, so imagine what could be happening at a microscopic level, right under your nose.
Nematodes, or more commonly referred to as roundworms, are by and large the most abundant species of animal on the planet. They account for just about eighty percent of individual animals on earth, according to the United States Department of Agriculture. (This was a run on sentence). But what is a nematode exactly? As it turns out, it’s more of a blanket term used to describe different species of microscopic parasitic worm that feed off of both plants and animals. Generally, however, they all play a crucial role in our ecosystems as one of the most successful multicellular microscopic life forms ever to exist.
Nematodes are the most numerous multicellular animals on earth. A handful of soil will contain thousands of these microscopic worms, many of them parasites of insects, plants, or animals. Free-living species are abundant, including nematodes that feed on bacteria, fungi, and other nematodes, yet the vast majority of species encountered are poorly understood biologically. There are nearly 20,000 described species classified in the phylum Nemata, and still some would estimate that there are about one million species of nematodes, however unfound the evidence for such estimations may be. These microscopic worms live all around you, and most likely inside of you as well, albeit harmless and unnoticeable when it comes to non-harmful species of roundworm. They live with us and are hardly noticed unless you place dirt under a microscope and look for them.
Many species of nematodes are ‘free-living’, meaning living in soil, sea and freshwater. These worms feed on bacteria, fungi, protozoans and even other nematodes, and play a very important role in nutrient cycling and release of nutrients into the soil for plant growth. Many of these free-living nematodes can grow up to a whopping seven metres, or twenty-three feet long. Other nematodes attack insects, and help to control their population this way. So the next time you get bit by a mosquito, just remember that it has its own parasite to deal with.
These predatory Nematodes eat all types of nematodes and protozoa. They eat smaller organisms whole, or attach themselves to the cuticle of larger nematodes, scraping away until the prey’s internal body parts can be extracted. These predatory nematodes are highly useful in controlling the populations of bacterial and fungal feeding nematodes, acting as a bio-control agent monitoring fungal and bacterial populations through grazing.
Nematodes are particularly important to the environment because of how they assist plant growth. They are a crucial part of nutrient exchange and can often be credited for some plants’ success. As stated, they also eat mosquitos from the inside out. Nematodes are usually considered pests because of the diseases they cause in humans and animals, and the economic impact they have on many agricultural products. There are, however, a small but significant number of beneficial entomogenous nematodes, i.e. nematodes associated (often parasitically) with insects. In addition to insects, nematodes can parasitize spiders, leeches, annelids, crustaceans and mollusks. Some of these entomopathogenic (insect-parasitic) nematodes are of considerable interest because of their potential as biological control agents of pest insects.
Once knowing all of this, it would be easy to fear these animals because of their parasitic nature; however, know that they’ve helped sustain the earth and its inhabitants for a long time. They are a giant part of the ecosystem, and without them we’d be knee deep in mosquitoes, biological waste, and grime. So the next time you step outside remember that it’s impossible for you to be alone out there.