Nemertea, more commonly known as ribbon worm, is an invertebrate that dwells mostly in oceans. Many people often find it difficult to distinguish it from the ordinary worm. However, the two are, in fact, completely different beings as ribbon worms have a complete gut and a circulatory system, whereas flatworms don’t.
You might already have heard of ribbon worms because they shoot out the white stuff that looks like spaghetti. But here, you will discover several other surprising facts about ribbon worms that you never have thought about before. Let’s check these facts out!
Table of Contents
- 1. The First Suspected Ribbon Worm Was Found About 500 Years Ago
- 2. No One Knows How Old Ribbon Worm Is
- 3. The Name Came From Greek Mythology
- 4. Ribbon Worm Spits Out Webs, Just Like a Spiderman
- 5. Some Are Parasite
- 6. It Has An Amazing Regenerate Ability
- 7. This One Ribbon Worms Could Produce Up To 200,000 New Ribbon Worms By Fragmentation
- 8. Ocean-Dwelling Ribbon Worm Can Grow Longer Than A Blue Whale
- 9. How Ribbon Worm Moves
- 10. Can Expand Twice Their Width To Swallow Their Prey
- 11. Ribbon Worms Are Heartless Animals
- 12. Ribbon Worm May Have 2 To 250 Eyes
- 13. Many Ribbon Worms Are Bright Colored
- 14. There Are Over 1000 Ribbon Worm Species In The World
- 15. They Are Only Able To Survive 10 Minutes In The Open Air
1. The First Suspected Ribbon Worm Was Found About 500 Years Ago
The first suspected ribbon worm was found in 1555 by a Swedish writer and cartographer, Olaus Magnus. He discovered a marine worm that was approximately “40 cubits” or 58.3 feet (17.8 meters) long. After that, William Borlase, a Cornish antiquary, geologist, and naturalist, mentioned a “sea long worm” in 1758.
About a decade later, in 1770, Johan Ernst Gunnerus described the longest animal in the world in a publication about sea animals of Norway, which he named Ascaris longissima. The creature underwent a long and complicated naming process due to classification debates until it was finally placed in the genus Nemertes and had its own phylum, Nemertea.
2. No One Knows How Old Ribbon Worm Is
Even if the first suspected ribbon worm was found in 1555, no one has an idea how old this worm is. The reason behind this is that ribbon worms, in fact, never leave any trace in the fossil record as they are members of invertebrates. They have soft bodies and are boneless.
This certainly becomes a big problem for scientists because they can’t determine how old ribbon worms are.
3. The Name Came From Greek Mythology
Now, you already know that the scientific name of ribbon worms is Nemertea. But do you know that the name Nemertea came from Greek mythology, Nemertes? In Greek mythology, Nemertes was the Nereid (God who inhabited the sea) and one of the 50 marine-nymph daughters of the ‘Old Man of the Sea’ Nereus and the Oceanid Doris.
Based on Ancient Greek, Nemertes itself means ‘truthful’ or ‘the giver’ or ‘the unerring’ which refers to the unerring aim of the proboscis. There are other names for this phylum, including Nemertini and Nemertinea. A German microscopist Max Johann Sigismund Schultze (1825–1874) came up with this name in 1851. However, it was only fully recognized and accepted as a valid phylum until the mid-20th century.
4. Ribbon Worm Spits Out Webs, Just Like a Spiderman
Don’t be flustered if you see a ribbon worm spitting out webs like a spiderman because it is just the way ribbon worms capture their prey. That white and web-like substance is named proboscis.
The thick and sticky texture of proboscis will help ribbon worms when hunting as it contains mucus that has neurotoxins which may paralyze the target. After that, the ribbon worm will devour its prey while drawing back the proboscis to its mouth. The proboscis is not only used to attack but to protect itself from predators as well.
5. Some Are Parasite
Although ribbon worms mostly are carnivores who use their proboscis to hunt prey, several species are living as parasites. For example, Carcinonemertes errans lives parasitic on Dungeness crab while eating the crab’s eggs.
This will reduce the capacity of egg production which consequently affects humans as well because crab is one of the commercially fished species. Not only crabs, but ribbon worms will also live as parasites on any animal they can find from the confines of its host.
6. It Has An Amazing Regenerate Ability
As we know, ribbon worms have a proboscis as a defense tool. Sometimes, they can’t pull back their proboscis when they are outside the water as it gets stickier. Instead, they will break off the proboscis to save its life from predators.
But you don’t need to worry because all ribbon worms have an amazing regenerate ability, so they can get lost or damaged parts of their bodies back, such as the proboscis. Not to forget that ribbon worms can survive without food for a long time while they wait for it to regenerate. Impressive, aren’t they?
7. This One Ribbon Worms Could Produce Up To 200,000 New Ribbon Worms By Fragmentation
The amazing ability to regenerate by ribbon worms is not only useful for restoring lost body parts, but also provides asexual reproduction. Ramphogordius sanguineus is one of the Nemerteans that use this mechanism to multiply its body. It transverse fission into small fragments that form mucous cysts, then turn into complete individuals.
This process works just like how ribbon worms regenerate their damaged body parts, but this time they also regrow a whole brain and head. Who would have thought a worm which was only 6 inches long could produce up to 200,000 new ribbon worms?
8. Ocean-Dwelling Ribbon Worm Can Grow Longer Than A Blue Whale
Did you know that ribbon worms that live in the ocean can grow longer than blue whales? Some of them measure up to 100 feet in length, although they are usually no more than an inch wide. The largest ribbon worm that has ever been reported is about 164 feet long.
It makes them one of the longest animals in the world as the longest blue whale on record was 110 feet 17 inches.
9. How Ribbon Worm Moves
If you ever wonder how ribbon worms move because they have no legs and also have no fins even though they live underwater, here we will give you the answer. Ribbon worms move their body by using slime and tiny hairs called cilia. With its external cilia, they all move slowly and glide on surfaces over the bottom.
The larger species are a little bit different. They used to crawl by stretching and contracting their soft bodies so that they have wave-like muscle contractions. Others swim by dorso-ventral undulations.
10. Can Expand Twice Their Width To Swallow Their Prey
The unfolding system of ribbon worms’ bodies is very important to them. Aside from moving, they expand their body about twice their width to swallow their prey. Hence, having a bigger target is not a problem for ribbon worms as they can easily eat it as a whole once they are done weakening their prey with the neurotoxins.
In fact, most ribbon worms can stretch up to 10 times their resting length. But when they are disturbed, some species tend to reduce it to 50% and increase their width to 300%.
11. Ribbon Worms Are Heartless Animals
There is no heart nor valves within ribbon worms’ closed circulatory systems. But unlike starfish, jellyfish, and other primitive heartless animals, ribbon worms still have blood running in their bodies. Because they are heartless, their blood flows in the vessels and is driven by muscle contractions throughout the body.
The blood vessels lie deep beneath the muscles of the body wall and may not be involved in oxygen transport.
12. Ribbon Worm May Have 2 To 250 Eyes
You might be surprised when you found out ribbon worms have quite a number of eyes. They may have 2 to 250 pigment-cup eyes with a narrow aperture, depending on the species. Ribbon worms use their eyes as a lens or light-detecting sensors and some species may be capable of forming images through theirs.
Other animals, including annelids, copepod crustaceans, abalone, and nautiloids also have this type of eye. Even though ribbon worms tend to have so many eyes, there is also an eyeless variant ribbon worm with a genus named Prostoma rubrum that lives in caves in Europe.
13. Many Ribbon Worms Are Bright Colored
Don’t be fooled by the beautiful appearance of ribbon worms. Many of them are bright-colored, most of them are yellow, orange, red, and green, and some have cute stripes patterns which are pleasing to see.
However, you don’t want to put these little creatures into your mouth because they are toxic and not edible. Just like mushrooms, the bright color of ribbon worms might be a sign of their poisonous nature.
Some of them can change colors throughout the year, for instance, male ribbon worms will become brighter during the breeding season.
14. There Are Over 1000 Ribbon Worm Species In The World
You probably never thought that the number of ribbon worm species would be this many. There are over 1000 ribbon worm species in the world, to be exact, there are 1300 valid and described species in approx. Most of them (about 900 species) live in oceans and some can be found in freshwaters or on land.
What’s surprising is that there are still many undiscovered ribbon worm species as the majority live in concealment, thus it requires such work even for the specialists. The change in the way of defining taxonomies that previously focused on internal anatomy based on the histological study to using generic data extensively also makes this even more difficult.
15. They Are Only Able To Survive 10 Minutes In The Open Air
Besides the remarkable facts about ribbon worms, there is also a sad fact. Some ribbon worms are only able to survive 10 minutes in the open air. They will die if they are not under seawater pressure because their delicate bodies rely on it to hold everything in place.
That’s why ribbon worms cannot stay away from the ocean. So, please help them to go back to where they live once you find them lost, okay?