The Goblin shark (Mitsukurina owstoni) is one of those shark species that leaves anyone who encounters it in astonishment. This shark looks like monsters from the prehistoric times, hence, sometimes referred to as a “Living Fossil”.
From the family Mistsukurinidae, this shark is the only extant member of a lineage dating back to over 125 million years ago. The goblin shark has a distinctive appearance with an elongated, flat snout that makes it look like a goblin, hence the name.
This shark species may not compete for size, speed, or even strength, but the goblin shark certainly has an atmosphere of mystery surrounding it. Therefore, this page is to highlight the amazing features of this species that you probably did not know.
Naming and Science Classification
The specific name of the goblin shark is Mitsukurina owstoni, its family is Mitsukurinidae and from the order Lamniformes. An American ichthyologist David Starr Jordan named this shark in honor of Professor Kakichi Mitsukuri of the University of Tokyo and a naturalist Alan Owston, who first got in contact with the specimen caught in Sagami Bay near Yokohama, Japan.
This shark’s common name “goblin shark” comes from the translation of its original Japanese name tenguzame. Where tengu is a mythical creature in japan depicted with a red face and long nose. And, zame means shark. This shark species also goes by the common name elfin shark.
Identifying a Goblin shark
Head
A major distinguishing feature of the goblin shark is its long and flat snout with the semblance of a sword blade. The length of this shark’s snout decreases as it ages. This shark has small eyes positioned just at the beginning of the snout, and it lacks the nictitating membrane which serves as a protective eyelid in most shark species. The eyes are generally black but with a bluish streak in the iris. Also, there are the spiracles located behind the eyes.
Dentition
The mouth is large with teeth looking like nails. There are about 35 – 53 teeth in the upper jaw and 31 – 62 teeth in the lower jaw. The jaw has teeth near the midpoint and also near the corners. Thus, the midpoint teeth have fine grooves, long, and narrow for cutting, while those at the corners appear flattened for crushing. Goblin sharks have protrusible jaws that extend during prey hunting almost to the end of the snout. However, under normal circumstances, the jaws will stay well-fixed against the underside of the head. There are very clear differences between individual tooth in size (length and width), the presence of cusplet on each side of the cusp, and the existence of toothless gaps between the midpoint (main) teeth and the rear teeth or at the symphysis.
Gills
The goblin shark has five pairs of gill slits which are short and partly exposing the gill filaments inside. And, the fifth pair of gill slit is just above the origin of the pectoral fin.
Body
The body of the goblin shark is a bit slender and flaccid, which is yielding to touch. This soft skin is semi-translucent with dermal denticles that give it a rough texture. Meanwhile, each dermal denticle has the shape of a short, upright spine with ridges running along the length. While this shark is still alive, it is pinkish or tan. This is because the blood vessels are visible beneath the semi-translucent skin. While the juvenile shark may be almost white, the color deepens as they age. However, after the goblin shark dies, the color quickly fades to a brown or dull gray.
Fins
This shark species has two dorsal fins which are similar in shape and size, thus, both of them are rounded and small. Even the pectoral fins have a rather similar appearance to the dorsal fins, small and rounded. There are also the larger pelvic and anal fins that have long bases. The caudal peduncle of the goblin shark lacks notches or keels and is flat checking from side-to-side. Also, the caudal fin is asymmetrical with a long upper lobe that has a shallow ventral notch near the tip and an undefined lower lobe. The margins of the fins are translucent gray or blue.
Growth Size
When fully grown, the goblin shark is usually about 9.8 – 13.1 feet (3 – 4 m) long. However, there exists a record of a female goblin shark captured that has an enormous approximate length of 18 – 20 feet (5.4 – 6.2 m). This suggests that this shark species can grow a lot larger than suspected.
The maximum weight recorded of this shark species is 460lb (210kg) measured by a 3.8m-long shark.
Where to Find a Goblin Shark
Having found the goblin shark in the Atlantic, Pacific, and Indian oceans suggest a wide but probably non-uniform global distribution. This shark has been recorded to occur in the following regions:
Atlantic Ocean
In the West – Gulf of Mexico, Southern Brazil, Suriname, and French Guiana.
In the east – Portugal, France, Madeira, and Senegal
Mid-Atlantic – Captured from seamounts along the Mid-Atlantic Ridge.
Indo-Pacific and Oceania
There are records of the goblin shark within this region in Mozambique, off South Africa, Taiwan, Japan, Australia, and New Zealand. Goblin sharks have also been recorded from off East Cape to Kaikoura canyon and from the challenger plateau near New Zealand.
In the eastern Pacific, there is a single individual known, caught off southern California.
Even with the wide distribution of goblin sharks, it is very rare to see one. This is because they prefer to live in water over continental slope commonly at depths of 890 – 3150 feet (270 – 960 m). Although, there are records of this shark captured at a depth of 4300 feet (1300 m). The juvenile goblin shark will naturally inhabit shallower waters than the adult, hence, immature sharks may swim up to depths of 328 – 1,148 feet (100 – 350 m) as they frequently do in the submarine canyons off southern Japan. They may also occasionally wander into inshore waters as shallow as 131 feet (40 m).
Hunting and Feeding Behavior of the Goblin Shark
While observations of the living goblin shark are rare, the structure of this shark suggests it is a slow and inactive species. However, this does not seem to affect the shark’s hunting efficiency. The goblin shark is likely an ambush predator that takes its prey unawares. Thus, with its large oily liver and low-density flesh, it can remain afloat without making many movements. By so doing, this shark will quietly drift close to its prey without detection. Once the prey is in range, the specialized jaws of this shark snap forward to capture the prey.
The jaw of the goblin shark has two pairs of elastic ligaments linked with the mandibular joint that helps the shark protrude its jaws during prey hunting. These ligaments are tightly drawn in position when the jaws are in the retracted state. But, as the shark attacks, the ligaments subsequently release their tension, catapulting the jaws as required, while the tongue helps the shark suck in its prey. This hunting technique likened to a slingshot may as well be a compensation for the goblin shark’s poor swimming ability, as such, it can catch fast and elusive prey without having to chase them.
The prey of goblin sharks includes bottom-dwelling fishes such as the black belly rosefish and mid-level species such as the ostracod and the squid. Goblin sharks will hunt for food near the seafloor and midwater. Other foods of this shark species are deep-living teleost fishes as dragonfish and rattails. They also feed on crustaceans, cephalopods, even isopods, and decapods.
Adaptations of the Goblin Shark
The anatomy of this shark species shows a poorly calcified and reduced skeleton, weakly developed blocks of muscles along its sides. This shark developed soft and small fins where the long caudal fin is held at a low angle typical of slow-swimming sharks. These features suggest a sluggish lifestyle for the goblin shark.
The soft elongated snout of this shark serves a sensory function as it features numerous ampullae of Lorenzini that can detect weak electric fields produced by other animals. Goblin sharks have relatively small optic tectum in their brain which suggests that vision is less important to these species. However, this shark can still adjust the size of its pupils meaning it probably makes use of its sight in certain situations. This is unlikely of most deep-sea sharks.
Do Goblin Sharks Have any Predators?
It is unclear the relationship of goblin sharks with the other sea-dwelling animals, but it appears the blue shark (Prionace glauca) is a predator to this species.
On the other hand, parasites recorded from this shark species include the Echthrogaleus mitsukurinae (copepod) and the Litobothrium amsichensis and Marsupiobothrium gobelinus (tapeworms).
Mating and Reproduction
There is only very little information available on the life cycle of goblin sharks. Much of this information suggests that this shark species may be sharing reproductive behavior with other mackerel sharks. This means viviparity with small litter sizes, including growing embryos during gestation feeding by oophagy which is ingesting undeveloped eggs. The size at birth is probably around 32 inches (81 cm), which is the size of the smallest recorded individual. There is no information on sexual maturity age, growth, and lifespan.
Until further research confirms the information on reproduction stated herein, they are still speculations by the experts.
Interaction between Goblin Sharks and Humans
The goblin shark poses no threat to humans as their habitat makes shark-human encounters very rare. On the other hand, this shark has very minimal economic value, hence commercial fisheries do not target it. Most of the occasionally captured specimens came as bycatch of commercial fishing in trawls, bottom gillnets, entangled in fishing gears, or hooked on long lines. And, most captures occur as isolated incidents. The jaws fetched high prices from collectors, while the flesh may be dried and salted.
Only very few specimens have been collected alive and taken to a public aquarium, though they did not survive for long. The goblin shark brought to the Tokai University only lasted a week, while the specimen kept at the Tokyo Sea Life Park only lived for two days.
Threat and Conservation
There is no significant threat to the goblin shark (Mitsukurina owstoni) known yet. Even as bycatch, this shark species is still rare. It is only once in an unusual occurrence that this shark was caught in large numbers more than one hundred off the northwest coast of Taiwan at approximately 1900 feet (600 m) depth. This incident took place in 2003 following a strong earthquake in the region.
Most of the captured specimens are juveniles, suggesting that the majority of the adult population is either occurring outside the depth range or not available to deepwater fisheries.
Following these, the IUCN in their Red List of threatened species listed the goblin shark as “Least Concern (LC)”.
In all, there is no information about the population size or trend for this species, so this grading is very much based on the inference that the scarcity of this species may be that the bulk population lives in areas outside fisheries, which could still be that they are naturally scarce.
Amazing Goblin Shark Facts at a Glance
1. The Goblin Shark Uses a Unique “Slingshot” Method of Hunting
This is among the most amazing features of this shark species, thus its jaws protrude to capture prey in range using the “slingshot feeding” method. The lower has velocity two times greater than the upper jaw because it does not only protrude forward but also swings in an upward direction.
2. Jaws are More Protrusible than Any Other Shark
Combining the measured protrusions of the goblin shark’s upper and lower jaws keeps this shark’s jaws at 2.1 – 9.5 times more protrusible than other sharks. Also, the maximum velocity of the jaws is 3.14m/s.
3. The Elongated Snout Decreases in Length as the Shark Ages
As this shark grows older, the long, flat snout will decrease in proportion with the age.
4. You Can See Through the Shark’s Skin
Incredibly, the pink coloration of the goblin shark does not come from any pink pigments in its skin, instead, this shark has a translucent skin that enables us to see oxygenated blood within its capillaries, thus resulting in the pink coloration.
5. “Goblin Shark” Translates from a Japanese Mythical Creature
The long nose of this shark did not fail to remind the Japanese fishermen of the mythical creature tengu known for its long nose and red face. As a result, they called this shark tengu-zame, where zame in Japanese translates as “shark”. Afterward, this was translated in English as “Goblin shark”.
6. This Shark is the Only Extant Member of its Family “Mitsukurinidae”
The goblin shark is from the family Mitsukurinidae which is part of the order Lamniformes, where the order contains other living sharks as the basking shark and great white shark. Mitsukurina owstoni is the only living species in its family.
7. Their Color Fades Out Once They Die
Immediately the goblin shark dies, it loses its pink coloration, as such, it turns to a brown or dull gray.
8. The Goblin Shark is a “Living Fossil”
With the goblin shark following a lineage dating back to some 125 million years ago, it is sometimes referred to as the “living fossil”. Another known living fossil is the Frilled Shark (Chlamydoselachus anguineus).
9. It Poses No Threat to Humans
The goblin shark is not dangerous to humans, of course, its natural habitat does not allow frequent human encounter. Therefore, this shark poses no threat to humans.
10. Goblin Sharks are Slow and Inactive
The morphology of the goblin shark shows that it is a slow-swimming, sluggish species. Although, it compensates with other features such as its ability to naturally remain buoyant with the help of its large oily liver, making this shark an effective ambush predator. To crown it all, this shark’s complex feeding method helps it capture even fast, elusive prey.
Last Thoughts
The goblin shark is a pretty amazing shark species with peculiar features. It is very rare from human sightings, as a result, there is not enough study of the lifestyle of this shark. This mostly touches the reproduction aspect of this shark as there is no pregnant female captured to aid the study.
Even the population size and trend are unknown, therefore, it is difficult to tell if this shark’s scarcity is due to its out-of-range habitat, or that they are naturally scarce.
Further Reading
- “Goblin Shark”, Wikipedia (edited 17 January 2020), Wikipedia. Online here
- “Mitsukurina owstoni (Goblin Shark)”, IUCN Red List of threatened species. Online here
- “Mitsukurina owstoni, Goblin shark”, FishBase. Online here
- “Biology of the Goblin Shark”, ReefQuest Centre for Shark Research. Online here
- “12 Facts About Goblin Sharks”, Mental Floss. Online here
- “10 Interesting Goblin Shark Facts”, Sharksider. Online here
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