Earth's Hidden World Is Not For The Squeamish.

Here at ARBICO we talk about nematodes a lot – specifically our Beneficial Nematodes. These microscopic creatures control a variety of pests in the soil through parasitization. Our customers love them because they are easy to use and highly effective. By the way, they are on sale now through the end of September.

As helpful as the nematodes we carry are, they are by no means the only kind of nematode (aka roundworm) out there and “beneficial” is not a term one would use to describe many of them. Although they are not often seen, nematodes are found literally everywhere on our planet, including intensely inhospitable places like the deepest ocean trenches (they make up 90% of the sea life on the ocean floor) and miles below the Earth’s surface. In fact, the only place they don’t seem to be is flying solo through the air, as they have no wings. Of all the animals on the globe, four out of five are nematodes. They survive and flourish spectacularly and (for the parasitic varieties) have developed fascinating ways to prey on and reproduce within their chosen hosts. While their sheer numbers are staggering, their seemingly endless variations and specializations are downright amazing.

There are 60 species of human parasitic nematodes that cause a very long list of ailments with symptoms that run from the merely uncomfortable to life-changing to fatal. Elephantitis is a particularly gruesome disease that is caused by the bite of a mosquito infected with the parasite. In this way, the nematode has hitched a ride on the insect to get to its ultimate human prey. Gastrointestinal disorders are probably the most common human condition caused by nematodes, some of which may pass through a person without them even noticing. These nematodes travel into the human gut through body openings to get to the nutrient-rich digestive system. This happens just like you think it does.According to the CDC (Centers for Disease Control and Prevention), Hookworms infect 576-740 million people worldwide. These parasites live in the soil and are picked up through the feet. But, how do they do that? According to this article, they locate their prey by smell (insert smelly feet joke here). And then they leap.

The nematodes I’ve been talking about are in the microscopic world, but they can get much, much bigger. Consider, if you will, Placentonema gigantissima. This is the largest known (anywhere from 9-28 feet) roundworm and lives in the placenta of sperm whales. With such an obscure hiding place, it’s no wonder it was not discovered until 1951. Marine nematodes contain not just the largest, but the smallest nematodes as well. We know this because there are scientists who study nematode penis size.

There is no shortage of yucky-yet-cool nematodes. Sphaerularia bombi, a bumblebee parasite is one such creature. Once it has reached maturity inside its host, the female’s uterus will expel from its genital opening and swell into a massive bumpy sack outside the body. This sack, easily twenty times the size of its body, becomes a giant feeding organ gorging itself on nutrients. Learn more here.

Sphaerularia bombi

Another nematode super-specialist is the Panagrellus redivivus. Nathan Cole, known as the father of Nematology in the US, first identified this non-parasitic guy back in the 19th century. This worm is very tolerant of acidity and alkalinity and has claimed some unique spots by feeding on yeast and living in vinegar and even German beer coasters. Although these nematodes are harmless, you may want to ensure that your vinegar is filtered.

Nematodes have been proven to be the culprit in a mystery from the Civil War. After the Battle of Shiloh in 1862, soldiers began noticing a couple of things: there was a greenish-blue glow coming from some of their untreated wounds and those that had the glow healed better than those without. With no knowledge of microbiology, they attributed this glow to a higher power and called the phenomenon “Angel’s Glow”. Fast forward to 2001, when a microbiologist and her son decided to take on the mystery. They figured out that the glow came from a nematode carrying a bioluminescent bacteria that feeds on microorganisms. As this shiny little bacteria fed on its preferred meal, it consumed microorganisms that could cause infection. Here is more on this time traveling detective story.

If the gross factor doesn't bother you, here are some videos showing roundworms in action. This one is a roundworm in a cat's intestine; this one is a large nematode eating a smaller one and this one is a roundworm emerging from a mosquito larvae.


As if it weren’t enough that nematodes dominate our life on earth, scientists are working on taking them to the next planet. It really does make sense, though, since they have so thoroughly saturated every aspect of life on earth. In order to replicate our world elsewhere, it would behoove us to include those roundworms that work for us in insect control and agriculture.

If you are still not convinced that nematodes are everywhere, you should know that they live in Bikini Bottom with Sponge Bob. And apparently have a voracious appetite.

Submitted by Pam