What Is the Scariest Deep Sea Creature?
The short answer
Our answer is the goblin shark. Its jaws sit folded under its head, then shoot out of its face like a slingshot. They reach out 8.6 to 9.4% of the shark's length. For its size, that is 2.1 to 9.5 times as far as in the nine other sharks measured.
On the way back, the mouth opens and shuts again. No other shark has been seen doing that, and nobody knows why.
How the slingshot works
At rest the jaws lie back under the eye, with the mouth slightly open and the long, thin teeth showing. Two pairs of ligaments at the jaw joints stay stretched while the jaws are folded back. When prey comes close, the jaws shoot forward under the long flat snout at up to 3.1 m a second and snap shut.
A team from Hokkaido University filmed goblin sharks about 1.3 m long and published the numbers in 2016. The jaw tips traveled 111 to 121 mm and closed under the snout, about halfway along it. The whole strike, out and back, took about 1.4 seconds. The team named it slingshot feeding, though nobody has measured the stored tension itself.
Farther, not proven faster
In the nine other sharks measured, the jaws reach only 0.9 to 4.0% of body length. So the record is reach for size, among the few species measured. In plain distance, a young goblin shark's 11 to 12 cm does not clearly beat a large lemon shark or white shark.
The paper calls the strike the fastest too, but it compares 3.1 m a second only with a ray (0.87 m a second) and a wrasse (2.31 m a second), never with another shark. That is why the film says farther, not faster.
On the way back the mouth opens again, to 46 to 48 degrees, then closes slowly. It is a softer second close, not a second bite. The authors offer only a mechanical guess at why.
The rest of the brag
Its skin is translucent and lacks pigment, so its blood shows through as pink. After death it turns brown or grey. The underside of its snout is covered in pores, the openings of electric sensors. Up close, a shark can feel the electric field that leaks from an animal's mouth and gills, which rises and falls as it breathes. Muscle signals, like a heartbeat, are usually out of range.
Japanese fishermen called it tengu zame, after the tengu, a long nosed, red faced goblin of Japanese folklore. Its family goes back more than 100 million years.
Key numbers
| What | Number | Source |
|---|---|---|
| How far the jaws reach, as a share of the shark's length | 8.6 to 9.4% | Nakaya et al. 2016, Scientific Reports |
| Jaw reach in the nine other shark species measured | 0.9 to 4.0% of body length | Nakaya et al. 2016, Scientific Reports |
| Goblin shark reach compared with those nine species | 2.1 to 9.5 times as far | Nakaya et al. 2016, Scientific Reports |
| Top speed of the jaws | 3.1 m a second | Nakaya et al. 2016, Scientific Reports |
| Distance the jaw tips traveled | 111 to 121 mm | Nakaya et al. 2016, Scientific Reports |
| Length of the filmed sharks | about 1.3 m | Nakaya et al. 2016, Scientific Reports |
| Whole strike, out and back | about 1.4 seconds | Nakaya et al. 2016, Scientific Reports |
| How wide the mouth opens again on the way back | 46 to 48 degrees | Nakaya et al. 2016, Scientific Reports |
| Jaw speeds the paper compares with: a ray and a wrasse | 0.87 and 2.31 m a second | Nakaya et al. 2016, Scientific Reports |
| Ligaments that hold the folded jaws | two pairs, at the jaw joints | Florida Museum of Natural History, Goblin shark profile |
| Age of the goblin shark's family | more than 100 million years | ReefQuest Centre for Shark Research, Family Mitsukurinidae |
What the film simplifies
- "I am the scariest creature in the deep sea" is the shark's brag and our pick, not a measured fact.
- The dentist's office and waiting room are cartoon. The dentist is drawn as a Japanese spider crab, which lives on the same coast of Japan where goblin sharks are caught.
- The X ray shows the ligaments as glowing bands. Ligaments would not show up on a real X ray.
- The film holds the jaws at full reach for a moment so the eye can catch them. The real strike, out and back, takes about 1.4 seconds.
- "Farther for his size than any shark ever measured" covers only the nine other species that have been measured, and the record is for reach compared with body size, not plain distance.
- The flatline is drawn. Frightened crabs do slow or stop their heart and breathing, but those studies were on other crabs, not the Japanese spider crab.
At a glance
Runtime 1 minute 3 seconds · Topics: Deep sea life, Sharks, Animal senses, How animals feed · Captions on YouTube · Full script below
Test yourself
The goblin shark's jaws travel 111 to 121 mm. Why does the film say "farther for his size" instead of just "farther"?
Answer
In plain distance, 11 to 12 cm from a 1.3 m young shark does not clearly beat a large lemon or white shark. As a share of body length, 8.6 to 9.4%, it beats the nine other species measured, which reach 0.9 to 4.0%.
A living goblin shark is pink, but a dead one is brown or grey. What makes it pink?
Answer
Its skin is translucent and lacks pigment, so the blood shows through.
A shark's snout can feel the electric field around another animal. Where on the animal does that field come from, and why does the film say the shark feels you breathe and not your heartbeat?
Answer
It comes mostly from the mouth and gills, where the body leaks into the water, and it rises and falls with each breath. Signals from muscles, like a heartbeat, are usually outside the range a shark can detect.
The script
Goblin shark: I am the scariest creature in the deep sea.
The dentist: Mm hmm. Open wide.
Host: He might be right. Meet the goblin shark.
Goblin shark: In Japan they named me after a goblin with a long nose.
Goblin shark: My family is over 100 million years old.
The dentist: It shows.
Goblin shark: Rude.
Goblin shark: I'm pink because you can see my blood through my skin.
The dentist: Seen it.
Goblin shark: My nose can feel you breathe.
The dentist: Seen it.
Host: He's not bluffing. Sharks feel the electric buzz around your gills.
The dentist: Open wide. Wider.
Goblin shark: Check the X ray.
Host: His jaws sit folded back on stretchy bands, pulled tight like a slingshot.
Goblin shark: You want wide?
Host: His jaws shoot out from under his nose. Farther for his size than any shark ever measured.
Goblin shark: On the way back, my mouth opens and shuts again. Nobody knows why.
Goblin shark: Seen that?
The dentist: Seen it.
Goblin shark: You stopped breathing.
The dentist: Next!
Sources
- Goblin shark jaws protrude at up to 3.1 m/s, 8.6 to 9.4% of total length (111 to 121 mm in sharks about 1.3 m long), 2.1 to 9.5 times the nine other shark species measured (0.9 to 4.0%); the cycle ends at about 1.4 s; the mouth reopens to 46 to 48 degrees during retraction, never observed in other sharks; speeds compared only with a ray (0.87 m/s) and a wrasse (2.31 m/s); 'slingshot feeding'.Nakaya et al. 2016, Scientific Reports
- Hokkaido University researchers measured jaw speeds of up to 3.1 m/s, far outranking the jaw protrusion of other sharks; the sharks opened and closed their mouths again during retraction for unknown reasons; slow swimming speed.Hokkaido University, 2016
- The jaws are thrust forward by a double set of ligaments at the jaw joints, stretched when the jaws are retracted; blood vessels visible through the skin make it look pinkish white.Florida Museum of Natural History, Goblin shark profile
- Fishermen called it tengu zame, after the long nosed, red faced tengu of Japanese folklore; its skin is translucent and lacks pigment, giving a pink tint from the bloodstream; brown or grey after death; exposed teeth.Natural History Museum, London
- The underside of the snout is heavily pored with the openings of the ampullae of Lorenzini, electric sensing organs; the mouth retracts under the eye and extends forward under the snout.Australian Museum, Goblin shark
- As the jaws close, two ligaments are stretched; opening the mouth releases the tension and the jaws are thrust forward.Australian Museum blog, McGrouther 2015
- Pink colour from blood showing through thin skin; tenguzame, after the tengu, depicted with red skin and a long nose; the snout is covered with ampullae of Lorenzini.Shark Trust, Creature feature: goblin shark
- The fishermen style it Tengu zame, meaning goblin or elfin shark; the first description of an adult goblin shark.Bean 1905, Proceedings of the US National Museum
- Prey electric fields are strongest at the mouth and gills and are modulated by breathing; muscle signals are typically outside sharks' detection range.Bedore and Kajiura 2013, Physiological and Biochemical Zoology
- Crabs show cardio inhibitory responses, a slowing of the heart, to every stimulus tested, including a real visual danger stimulus.Burnovicz et al. 2009, Journal of Experimental Biology
- The goblin shark's lineage (Mitsukurinidae) goes back some 124 to 112 million years, to the fossil Anomotodon principalis.ReefQuest Centre for Shark Research, Family Mitsukurinidae