GOBLIN SHARK

Taxonomy:

Phylum– Chordata

Class– Chondrichthyles

Order– Lamniformes

Common Name– Mackerel Sharks

Family– Mitsukurinidae

Common Name– Goblin Sharks

Genus– Mitsukurina

Species– owstoni

Status: IUCN Red List LEAST CONCERN

Average Size and Length: Their length at birth is unknown, but juveniles have been measured at less than 107 cm/3.5 feet. Mature males have been measured at less than 264 cm/8.7 feet. Mature females have been measured at less than 335 cm/11 feet. The maximum recorded have been measured at over 500 cm/16.4 feet.

Average Weight: The maximum weight recorded is 460 pounds for a 12.5-foot-long shark.

Current Rare Mythical Sightings: The Goblin shark was discovered in 1897. American ichthyologist David Starr Jordan described the Goblin shark in an 1898 issue of Proceedings of the California Academy of Sciences, recognizing it not only as a new species, but also a new genus and family. He based his account on an immature male 3.5-foot-long caught in Sagami Bay near Yokohama, Japan. The specimen had been acquired by shipmaster and naturalist Alan Owston, who had given it to Professor Kakichi Mitsukuri at the University of Tokyo, who then brought it to Jordan. Jordan named the shark Mitsukurina owstoni in honor of these two men. The common name “Goblin shark” is a translation of its old Japanese name “tenguzame”, a “tengu” is a Japanese mythical creature often depicted with a long nose and red face. The Goblin shark has also been called the Elfin shark. It surely looks like a character straight out of the head of Jim Henson.

Soon after Jordan’s description was published, several scientists noted the similarity between Mitsukurina and the extinct Mesozoic shark Scapanorhynchus. Many scientists advocated to treat them as synonyms. However, over time, more complete fossils revealed many anatomical differences between Scapanorhynchus and Mitsukurina, thus, leaving the two as distinct genera.

Phylogenetic studies based on morphology and genetic data studies have classified the Goblin shark as the most basal member of the order Lamniformes. The family Mitsukurinidae, represented by Mitsukurina, Scapanorhynchus, Anomotodon, Protoscapanorhynchus, and Pseudoscapanorhynchus, dates back to the Aptian age of the Cretaceous period (c. 125–113 Ma). Mitsukurina first appears in the fossil record during the period Middle Eocene (c. 49–37 Ma). Extinct species include M. lineata and M. maslinensis. Striatolamia macrota, which lived in warm shallow waters during the Paleogene period (c. 66–23 Ma), may also be a Mitsukurina species.

(Vialle, N.; Adnet, S.; Cappetta, H. (2011). “A new shark and ray fauna from the Middle Miocene of Mazan, Vaucluse (southern France) and its importance in interpreting the paleoenvironment of marine deposits in the southern Rhodanian Basin“. Swiss Journal of Palaeontology. 130 (2): 241–258.)

(Purdy, R. (2005). “Is Striatolamia a junior synonym of Mitsukurina?”. Journal of Vertebrate Paleontology. 25 (3): 102A.)

Teeth and Jaw: The large mouth is parabolic in shape. The Goblin shark has highly protrusible jaws. They can be extended almost to the end of the snout, though normally they are held flush against the underside of the head. The teeth are slender and long-cusped. The back teeth are modified to crush food. It has 35–53 upper and 31–62 lower tooth rows. Goblin sharks have 26 large, narrow, awl-like teeth on their upper jaw and 24 on their lower jaw. The teeth in the main part of the jaws are long and narrow, particularly those near the symphysis, and are finely grooved lengthwise. The rear teeth near the corners of the jaw are small and have a flattened shape for crushing. There is individual variation of tooth length and width, as for whether the teeth have a smaller cusplet on each side of the main cusp, and regarding the presence of toothless gaps at the symphysis or between the main and rear teeth.

Head: The Goblin shark has an unmistakable flat, elongated snout covered with ampullae of Lorenzini. According to Parsons (2002), the snout length decreases proportionally with age. The eyes are small and lack protective nictitating membranes and behind the eyes are spiracles. The eyes are black with bluish streaks in the irises. It can change the size of its pupils.

Denticles: Goblin sharks have small and rough dermal denticles. The denticles have crowns with narrow cusps and ridges. The cusps of the lateral denticles are perpendicular to the skin. They are shaped like a short upright spine with lengthwise ridges. With their flabby body and pinkish color, they must feel extremely strange and not of this Earth.

Tail: The caudal fin is asymmetrical in shape and held at a low angle. The tail fin is long and it lacks a ventral lobe. The caudal peduncle is flattened from side-to-side and lacks keels or notches.

Demographic, Distribution, Habitat, Environment and Range: The Goblin shark can be found in the Atlantic Ocean and the western Indian Ocean and in the Pacific. The distribution is patchy. In the Atlantic Ocean, it has been recorded from the northern Gulf of Mexico, off the coast of Key West, Suriname, French Guiana, and southern Brazil in the west, and France, Portugal, Madeira, and Senegal in the east. It has also been collected from seamounts along the Mid-Atlantic Ridge. In the Indo-Pacific it has been found off South Africa, Mozambique, Japan, Taiwan, Australia and New Zealand. It has also been recorded from off East Cape to Kaikoura Canyon and from the Challenger Plateau near New Zealand. A single eastern Pacific specimen is known, collected off southern California.

Records have shown that mature females visit the east coast of Honshu during the springtime, which could be related to reproduction patterns.

They can be found in deep water on the outer continental shelves, the upper slopes, submarine canyons, and off of seamounts. They are rarely found at the surface or between 312-450 feet. They mainly stay between 886-3,150 feet, but will go to at least 4,265 feet. Adults are typically found deeper than juveniles.

Diet: Their slender front teeth suggests a diet of small, soft bodied fish and squid. Their back teeth are modified to crush food. It hunts for prey in the middle of the water column and on the sea floor. Stomach contents have confirmed this, and that they feed on a variety of marine fish and squid.

Garbage has been recorded from the stomachs of some specimens (Yano, K.; Miya, M.; Aizawa, M.; Noichi, T. (2007). “Some aspects of the biology of the goblin shark, Mitsukurina owstoni, collected from the Tokyo Submarine Canyon and adjacent waters, Japan“. Ichthyological Research. 54 (4): 388–398.).

It has been suggested that Goblin sharks may prey upon Blue sharks (Prionace glauca).

Ram-Suction Index: The Goblin shark is a combination of ram and suction, however confirmed in video evidence that they are much higher on the ram side of the index. The highly specialized jaws can shoot forward rapidly to snap up unsuspecting prey and expands its oral cavity and sucks down water and prey. It works like a slingshot.

According to recent studies from a scientific team, what makes the Goblin shark unique is the kinematics of their jaw when feeding. The lower jaw seems to undergo more complex movements and is important in capturing the prey. The measured protrusions of the upper and lower jaw combined put the goblin shark jaws at 2.1–9.5 times more protrusible than other sharks. The lower jaw has a velocity about two times greater than the upper jaw because it not only protrudes forward, but also swings upward to capture the prey, and the maximum velocity of the jaws is 3.14 m/s. The Goblin shark has a re-opening and re-closing pattern during the strike, a behavior that has never been seen in other sharks before and could be related to the extent with which the goblin shark protrudes its jaws. (Nakaya, K.; Tomita, T.; Suda, K; Sato, K. (2016). “Slingshot feeding of the goblin shark Mitsukurina owstoni (Pisces: Lamniformes: Mitsukurinidae)“. Scientific Reports. 6 (27786)).

Aesthetic Identification: The body of the Goblin shark is soft, flabby and pinkish white and semi-translucent in color. Living sharks are pink or tan due to visible blood vessels beneath the skin. The color deepens with age, and young sharks may be almost white. After death, the coloration fades quickly to dull gray or brown. The fin margins are translucent gray or blue. The five pairs of gill slits are short, with the gill filaments inside partly exposed. The fifth pair is above the origin of the pectoral fins. The fins are small. The two dorsal fins are similar in size and shape, both being small and rounded. The pectoral fins are also rather small and rounded. The pelvic and anal fins have long bases and are larger than the dorsal fins.

Biology and Reproduction: Their biology is very poorly known. The skeleton of the Goblin shark is reduced and poorly calcified, the muscle blocks along its sides, called myomeres, are weakly developed.

Its low-density flesh and large oily liver make it neutrally buoyant, allowing it to drift towards its prey with minimal motions so as to avoid detection. Once prey comes into range, the shark’s specialized jaws can snap forward to capture it. The protrusion of the jaw is assisted by two pairs of elastic ligaments associated with the mandibular joint, which are pulled taut when the jaws are in their normal retracted position; when the shark bites, the ligaments release their tension and essentially “catapult” the jaws forward. At the same time, the well-developed basihyal (like a tongue) on the floor of the mouth drops, expanding the oral cavity and sucks down water and prey. It works like a slingshot.

Little is known about Goblin shark reproduction. More than likely it shares similar characteristics to other Lamniformes. It is more than likely ovoviviparous, probably small litter sizes and embryos that engage in oophagy. Birth length is more than likely around 82 cm/2.7 feet. Research also suggests that males may mature around 8.5 feet.

Parasites documented from the Goblin shark include the copepod Echthrogaleus mitsukurinae, and the tapeworms Litobothrium amsichensis and Marsupiobothrium gobelinus.

(Izawa, K. (2012). “Echthrogaleus mitsukurinae sp. nov (Copepoda, Siphonostomatoida, Pandaridae) infesting the goblin shark Mitsukurina owstoni Jordan, 1898 in Japanese waters“. Crustaceana. 85 (1): 81–87).

(Caira, J.N.; Runkle, L.S. (1993). “2 new tapeworms from the goblin shark Mitsukurina owstoni off Australia“. Systematic Parasitology. 26 (2): 81–90).

Behavioral Traits, Sensing and Intelligence: The blade-like snout of the Goblin shark is covered in ampullae of Lorenzini and is used to detect prey. Due to the snout’s softness, it is unlikely to be used for stirring up prey from the bottom as has been proposed. Vision seems to be less important than other senses, considering the relatively small optic tectum in the shark’s brain. However, unlike most deep-sea sharks, it can change the size of its pupils, so it probably does use its sight in some situations.

Its body suggests that it is sluggish and inactive in nature. They are more than likely ambush predators, with the adaptive evolution of its unique jaws and slingshot feeding techniques, it can catch fast-moving prey without matching or exceeding the prey’s movements or speed, i.e. chasing it.

Speed: The body of the Goblin shark suggests that it is a poor and awkward swimmer, and now that they have been filmed swimming, this can be confirmed.

Goblin Shark Future and Conservation: They are of least concern. They are occasionally caught as bycatch from deepwater fisheries. Its economic significance is minimal and not targeted by fisheries. The meat may be dried and salted, while the jaws raise high prices from collectors. At one time, the Japanese also used it for liver oil and fertilizer.

Most captures are isolated incidents. One of the few areas where it is caught regularly is off southern Japan, where around 30 individuals that are mostly juveniles are taken each year.

During April 2003, more than a hundred Goblin sharks were caught off northwestern Taiwan. The cause of the event was unknown, though observers noted it was preceded by a major earthquake. Before that event, the Goblin shark was never recorded there, and has not been recorded there since.

A tooth of a Goblin shark has been found lodged in an undersea cable at a depth of 4,495 feet.

On the 19^th of April in 2014, shrimper fishermen right here in Florida, in Key West, while fishing in the Gulf of Mexico, caught a Goblin shark in their fishing net, only the second one ever to be caught in the Gulf. The shark was photographed and released back into the water. To quote the fishermen: “man he’s ugly!” (https://www.cnn.com/2014/05/04/us/florida-goblin-shark/index.html).

During July 2014, a Goblin shark was found in a commercial fishing net near the eastern coast of Sri Lanka. The shark was about 4 feet long and weighed about 17 pounds. It was given to the NARA (National Aquatic Resource Research & Development Agency) for further research.

Goblin sharks are not meant for captivity, however sadly, there have been some attempts. A few specimens have been collected alive and brought to public aquariums, though they only survived briefly. One was kept at Tokai University and lived for a week, while another was kept at Tokyo Sea Life Park and lived for two days.

During June 2018, the New Zealand Department of Conservation classified the Goblin shark as “At Risk – Naturally Uncommon” with the qualifiers “Data Poor” and “Secure Overseas” using the New Zealand Threat Classification System.

Goblin Shark Recorded Attacks on Humans: Not a threat to humans.

 

(Parsons, G.R.; Ingram, G.W.; Havard, R. (2002). “First record of the goblin shark Mitsukurina owstoni, Jordan (family Mitsukurinidae) in the Gulf of Mexico”. Southeastern Naturalist. 1 (2): 189–192.)