There are some living fossils swimming around in the depths of the ocean, and if you take a closer look at this ocean monster, then you surely understand why they are being referred to as such.
In this post, we’ll take a closer look at some remarkable facts about frilled shark, some of the most frightening creatures on the planet!
Interesting frilled shark facts
1. They got their name from one of their remarkable features
The frilled shark is a relatively large type of shark that lives in the depths of the ocean. It’s referred to as a “frilled” shark because of its distinctive gill slits that are situated near its throat.
Apart from its most common name, this animal is also referred to as either the “lizard shark” or the the “scaffold shark.”
2. Their scientific name is a reference to another fish
This fish is known by its scientific name as “Chlamydoselachus anguineus.” The first word is a combination of two Greek words, “chlamy” which means frill, and “selachus” which means shark. “Anguineus” is a Latin word which means “like an eel.”
And yes, these sharks really have an eel-like body, so it’s an eel-like shark with a frill.
3. There’s only 1 other extant member in their family
Ever since this shark species was first described it has been referred to as “An Extraordinary Shark.” That’s why they have been put in their own family referred to as Chlamydoselachidae. They’re also part of the sole extant genus in this family called Chlamydoselachus.
In this genus, there are only two extant species out of the 13 that originally belonged to it. Apart from the frilled shark (Chlamydoselachus anguineus), there’s also the southern African frilled shark (Chlamydoselachus africana).
Apart from being in the same genus, these two species differ quite a bit anatomically. The southern African frilled shark has distinctively shorter head and gill slits, as well as a shorter spinal column and spiral valve.
4. They are referred to as living fossils
Frilled sharks are referred to as “living fossils,” mainly because they are direct descendants of animals living in the Carboniferous period between 360 million and 300 million years ago.
Unlike for example Giant Isopods which have remained pretty much the same for millions of years, these animals did evolve significantly and didn’t look quite the same as they do today back then.
5. They were first described in the late 19th-century
The frilled shark was first described in the year 1884 by American zoologist Samuel Garman in the “Bulletin of the Essex Institute” (vol. XVI). He’s the man who referred to this animal as an extraordinary shark and also put it into his very own family and genus.
His description was based on a female shark that was discovered in Sagami Bay in Japan.
Regardless of the initial observations of Garman and other scientists, it wasn’t quite sure to which class this animal really belonged until fairly recently. Garman thought it might belong to the extinct “cladodont sharks” that lived in the Devonian period (419 to 359 million years ago).
Other scientists such as Theodore Gill and Edward Drinker Cope put it into the Hybodontiformes, the closest group related to modern-day sharks and rays.
A study conducted in 2016 concluded that it’s related to the order “Hexanchiformes,” the most primitive types of sharks of which only 7 extant species swim in the depths of the world’s oceans today.
This includes one of the oldest species of sharks, the cow shark, a type of shark closest related to ancient extinct forms.
7. How big are frilled sharks?
The first shark ever described had a length of about 1.5 meters (4 feet 11 inches). This means that it wasn’t fully developed yet because they usually grow quite a bit longer.
The maximum length of female frilled sharks was about 2 meters (6.6 feet), while the biggest male individual was shorter with a maximum length of just 1.7 meters (5.6 feet).
The color of these animals ranges from a uniform dark brown to a uniform dark grey.
8. They live in various parts of the Atlantic and Pacific Oceans
So where do frilled sharks live?
It’s true that we don’t want to come across any of these creatures any time soon, and we don’t need to worry about that. These animals live in the depths of the ocean and are usually found at depths of anywhere between 50 meters (160 feet) and up to 1,570 meters (5,150 feet).
In the waters near Japan, they are pretty common at depths of anywhere between 50 and 200 meters (160 and 660 feet), while in other locations it’s pretty uncommon to find them below 1,000 meters (3,300 feet).
These creatures are found all around the world on the continental shelf and the upper-to-middle continental slope of the Atlantic and Pacific Oceans.
9. They move up and down the ocean to find food
One of the most remarkable frilled shark facts is that they use their liver to control its buoyancy. This organ allows them to move up and down the ocean.
This is needed because this animal moves up towards the ocean’s surface at night in order to find food, a process referred to as diel vertical migration.
10. These ferocious predators eat a wide variety of other animals
The diet of these ocean predators mostly consists of cephalopods (such as squid and octopus), smaller sharks, and bony fish.
About 60 percent of their diet consists of various types of squid and much smaller sharks which they swallow whole.
11. Their jaws are equipped with 300 extremely sharp teeth
One of the most remarkable features of this type of shark is the curved teeth in their jaws. These consist of up to 300 teeth in between 19 and 28 upper rows and 21 and 29 lower rows.
These teeth are positioned in such a way that they can easily grab the soft flesh of their prey, unfortunate creatures that don’t stand a chance against this ferocious creature!
12. They can swallow large prey because of their specialized jaws
Another one of those interesting frilled shark facts is that these animals have specialized jaws which allows them to swallow prey that is much larger than themselves. These jaws are connected to a point behind their eyes, allowing them to open their mouth much wider than with jaws directly connected to the cranium.
On the other hand, this also means that they have a relatively weak bite as they aren’t able to put much force with their jaws. Therefore its also assumed that they hunt with their mouths wide open and only close it if the prey is already partially inside. They exert negative pressure so that prey is sucked into their mouths and their razor-sharp and gripping teeth do the rest.
As their mouths are wide open, it’s also assumed that their remarkable white teeth, which are in sheer contrast to the pitch dark of the bottom of the ocean, serve as a form of lure
13. They are not always the predator but sometimes the prey as well
Perhaps even more astounding is the fact that this type of shark isn’t always the predator, but also sometimes the prey!
Scientists have come to this conclusion because some individuals that were found were missing some parts of their bodies such as the tip of their tails. That means they also sometimes have to swirl their eel-like bodies away from other fish as opposed to directly at them.
14. These animals have an extremely long gestation period
One of the most fascinating facts about frilled sharks is that they are extremely slow to reproduce. The gestation period can last up to 3.5 years with anywhere between 2 and 15 little ones being born at once with the average being 6.
The average growth rate of the embryos is about 1.4 centimeters (0.55 inches) per month which means that the little sharks are born when they reach a length of anywhere between 40 and 60 centimeters (16 and 24 inches)!
15. This type of shark is not considered to be endangered
Because of their vast range and the extreme depth they live at, it’s unclear how many individuals are swimming around in the ocean today. That being said, commercial fishing is a real threat to these animals because it can seriously deplete their sources of food.
The risk attached to overfishing once urged the IUCN Red List to classify this species as “near-threatened,” but this has been altered to “least Concern” since 2016.