Mitsukurina owstoni develop directly from birth, and are probably ecologically similiar to free-swimming adults when they emerge from the mother. It is not known at what age they become sexually mature, but are immature to about 2.3 m.
Mitsukurina owstoni is a fearsome looking fish with a large, flattened snout protruding from the top of its head, and has movable jaws than can extend to catch prey. The exact purpose of the flat snout is unknown, but as it is not hard or sharp enough to pin or kill prey, it is probably used to detect the faint electric signals that other fish give off. Goblin sharks have rubbery skin, rather than denticles (the sharp, pointed scales found on most sharks). Due to the blood vessels that are close to the skin, the shark has a pinkish-grey color in life, though in death it appears quite colorless because of its lack of pigment. Teeth are slender and fang-like, similar to those of the sand tiger shark. Another feature that separates goblin sharks from most other sharks is the lack of a lower lobe on the tail fin, which is also absent in other benthic sharks. Female specimens seem to be slightly larger than the males.
Range length: 107 to 380 cm.
Average length: 160 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: female larger
No goblin sharks have been studied in the wild, so not much is known about their ages or lifespans. No individuals have ever been held in captivity.
Goblin sharks seem to live in the mid and deep-water zones of outer continental shelves and slopes.
Range depth: 40 to 1200 m.
Habitat Regions: temperate ; saltwater or marine
Aquatic Biomes: pelagic ; benthic
Originally caught in Japan, the range is wide, but not evenly distributed. The majority of known specimens come from bays of Japan while the rest are mostly found off New Zealand, southern Africa, and in the Eastern Atlantic and Indian Oceans. Two specimens have been taken off the Mississippi and California coasts of the United States. Though this probably encompasses the range of Mitsukurina owstoni, sightings are so rare and widespread that the presence of goblin sharks could extend well beyond these areas.
Biogeographic Regions: nearctic ; palearctic ; australian ; indian ocean; atlantic ocean ; pacific ocean
Mitsukurina owstoni appears to feed mid-water or close to the bottom where it uses a combination of electrical sensors, smell and (minimal) eyesight to catch any vertically migrating animals that it comes across. It is also possible that they stay deep and scan the bottom for prey. Stomach records are rare, and include parts of squid, fish, ostracods, and crabs.
Animal Foods: fish; mollusks; aquatic crustaceans
Primary Diet: carnivore (Piscivore , Eats non-insect arthropods, Molluscivore )
As it is often difficult to deduce ecosystem roles in easily studied environments, it comes as no surprise that nothing is known about goblin sharks' role in the mid-water or benthic community besides its role as a predator.
Mitsukurina owstoni has minimal economic importance. Apparently it is sometimes fished commercially off Japan.
Positive Impacts: food
There are no known adverse affects of goblin sharks on humans.
The goblin shark is rarely found, but not thought to be threatened.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Like all sharks, goblin sharks probably hunt using their senses of smell, sight, sound and the electrical sensing organs called ampullae of Lorenzini. Due to the depth at which they live, eyesight is probably less useful than other senses. The snout (which is abnormally large in Mitsukurina owstoni) houses the ampullae of Lorenzini which are attuned to catching otherwise undetectable prey in dark waters or on the bottom.
There is no available data on communication within the species.
Perception Channels: visual ; acoustic ; chemical ; electric
Most of the biology of Mitsukurina owstoni is unknown due to the rarity of sightings and specimens. However, though rarely seen, this shark is thought to be fairly common because of its wide range. Nonetheless, because it lives in deep waters, is not a common sight for humans. Most of the information is partial, and deduced from the morphology of the shark and from samples of the few existing specimens. Other common names include: imp shark, elfin shark, and tenguzame(Japanese). Differences in extension of jaws in death lead to confusion over how many species of Mitsukurina there actually are. As of now, there is only one recognized species. However, the extant goblin shark is considered to be very closely related to a similar Cretaceous shark genus Scapanorhynchus, known from fossils.
There are no known predators of the goblin shark except for infrequent Japanese fishermen.
There has been no direct study of goblin sharks in the wild, so there is no information on there mating habits.
Goblin sharksare rarely seen, and even more rarely studied in detail. Essentially all known data on goblin sharks are from accidental catches in trawling nets. Thus, since there have been no opportunities to observe goblin sharks in their natural habit (or even alive for that matter), data on reproduction and behavior are very scarce. There is no information on age at sexual maturity for either sex, number of offspring, or gestation period.
Most sharks are independent as soon as they are born. This is probably not different in the case of the goblin shark.
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); ovoviviparous
Though there are no data for goblin sharks in particular, sharks in general do not provide any degree of parental investment.
Parental Investment: no parental involvement
The goblin shark (Mitsukurina owstoni) is a rare, poorly known species of deep-sea shark. Sometimes called a "living fossil", it is the only extant representative of the family Mitsukurinidae, a lineage some 125 million years old. This species looks unlike any other shark, with a long flattened snout, highly protrusible jaws containing prominent nail-like teeth, and pink coloration. It is usually between three and four meters (10–13 ft) long when mature, though can grow considerably larger. Goblin sharks inhabit upper continental slopes, submarine canyons, and seamounts around the world at depths greater than 100 m (330 ft), with adults found deeper than juveniles.
Various anatomical features of the goblin shark, such as its flabby body and small fins, suggest that it is sluggish in nature. This species hunts for teleost fishes, cephalopods, and crustaceans both near the sea floor and in the middle of the water column. Its long snout is covered with ampullae of Lorenzini that enable it to sense minute electric fields produced by nearby prey, which it can snatch up by rapidly extending its jaws. Small numbers of goblin sharks are unintentionally caught by deepwater fisheries. The International Union for Conservation of Nature (IUCN) has assessed it as Least Concern, citing its wide distribution and low incidence of capture.
From Wikipedia 2013
The goblin shark (Mitsukurina owstoni) is a rare species of deep-sea shark. Sometimes called a "living fossil", it is the only extant representative of the family Mitsukurinidae, a lineage some 125 million years old. This pink-skinned animal has a distinctive profile with an elongated, flat snout, and highly protrusible jaws containing prominent nail-like teeth. It is usually between 3 and 4 m (10 and 13 ft) long when mature, though it can grow considerably larger such as one captured in 2000 that is thought to have measured 6 m (20 ft).[3] Goblin sharks are benthopelagic creatures that inhabit upper continental slopes, submarine canyons, and seamounts throughout the world at depths greater than 100 m (330 ft), with adults found deeper than juveniles. Some researchers believe that these sharks could also dive to depths of up to 1,300 m (4,270 ft), for short periods of time.[3]
Various anatomical features of the goblin shark, such as its flabby body and small fins, suggest that it is sluggish in nature. This species hunts for teleost fishes, cephalopods, and crustaceans both near the sea floor and in the middle of the water column. Its long snout is covered with ampullae of Lorenzini that enable it to sense minute electric fields produced by nearby prey, which it can snatch up by rapidly extending its jaws. Small numbers of goblin sharks are unintentionally caught by deepwater fisheries. The International Union for Conservation of Nature (IUCN) has assessed it as Least Concern, despite its rarity, citing its wide distribution and low incidence of capture.
American ichthyologist David Starr Jordan described the goblin shark in an 1898 issue of Proceedings of the California Academy of Sciences, recognizing the peculiar fish not only as a new species, but also a new genus and family. He based his account on an immature male 107 cm (42 in) 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 in turn had brought it to Jordan. Thus, Jordan named the shark Mitsukurina owstoni in honor of these two men.[4]
The generic name honors Keigo Mitsukuri, a Japanese zoologist who studied at University College London during the 1860s. The specific name honors Alan Owston, an English collector of Asian wildlife.[5] The common name "goblin shark" is a calque of its traditional Japanese name tenguzame, a tengu being a Japanese mythical creature often depicted with a long nose and red face.[6] Another name for this species is elfin shark.[2]
Soon after Jordan's description was published, several scientists noted the similarity between Mitsukurina and the extinct Mesozoic shark Scapanorhynchus.[7] For a time, the prevailing opinion was to treat Mitsukurina as a junior synonym of Scapanorhynchus. Eventually, more complete fossils revealed many anatomical differences between Scapanorhynchus and Mitsukurina, causing modern authors to again regard them as distinct genera.[8] Several goblin shark specimens were described as separate species from 1904 to 1937, none of which are now considered valid. This taxonomic confusion began because the specimens' jaws were fixed at varying degrees of protrusion during preservation, giving the appearance of proportional differences among the heads.[9]
Phylogenetic studies based on morphology have classified the goblin shark as the most basal member of the order Lamniformes, known as mackerel sharks.[10][11] Studies using genetic data have also confirmed a basal classification for this species.[12][13] The family Mitsukurinidae, represented by Mitsukurina, Scapanorhynchus, and Anomotodon, dates back to the Aptian age of the Cretaceous period (c. 125–113 Ma). Mitsukurina itself first appears in the fossil record during the period Middle Eocene (c. 49–37 Ma);[14][15] extinct species include M. lineata and M. maslinensis.[16][17] Striatolamia macrota, which lived in warm shallow waters during the Paleogene period (c. 66–23 Ma), may also be a Mitsukurina species.[18] As the last member of an ancient lineage, and one that retains several "primitive" traits, the goblin shark has been described as a "living fossil".[19]
The goblin shark has a distinctively long and flat snout, resembling a blade. The proportional length of the snout decreases with age.[20] The eyes are small and lack protective nictitating membranes; behind the eyes are spiracles. The large mouth is parabolic in shape. The jaws are very protrusible and can be extended almost to the end of the snout, though normally they are held flush against the underside of the head. It has 35–53 upper and 31–62 lower tooth rows. The teeth in the main part of the jaws are long and narrow, particularly those near the symphysis (jaw midpoint), and are finely grooved lengthwise. The rear teeth near the corners of the jaw are small and have a flattened shape for crushing. Much individual variation of tooth length and width occurs, 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. 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.[6][8][21]
The body is fairly slender and flabby. 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. The caudal peduncle is flattened from side-to-side and lacks keels or notches. The asymmetric caudal fin has a long upper lobe with a shallow ventral notch near the tip, and an indistinct lower lobe.[8][21] The soft, semitranslucent skin has a rough texture from a covering of dermal denticles, each shaped like a short upright spine with lengthwise ridges. Living sharks of this species are pink or tan due to visible blood vessels beneath the skin; the color deepens with age, and young sharks may be almost white. The fins' margins are translucent gray or blue, and the eyes are black with bluish streaks in the irises. After death, the coloration fades quickly to dull gray or brown.[6][9] Adult sharks usually measure between 3 and 4 m (9.8 and 13.1 ft) long.[6] However, the capture of an enormous female estimated at 5.4–6.2 m (18–20 ft) long during 2000 showed this species can grow far larger than suspected previously.[20] A 2019 study suggested that it would have reached 7 m (23 ft) in maximum length.[22] The maximum weight recorded is 210 kg (460 lb) for a shark of 3.8 m (12.5 ft) in length.[8]
The goblin shark has been caught in all three major oceans, indicating a wide global distribution. In the Atlantic Ocean, it has been recorded from the northern Gulf of Mexico, Suriname, French Guiana, and southern Brazil in the west, and France, Portugal, Madeira, and Senegal in the east.[2][6][23] It has also been collected from seamounts along the Mid-Atlantic Ridge.[24][25] In the Indo-Pacific and Oceania, it has been found off South Africa, Mozambique, Japan, Taiwan, Australia and New Zealand. This species has been recorded from off East Cape to Kaikōura Canyon and from the Challenger Plateau near New Zealand.[26] A single eastern Pacific specimen is known, collected off southern California.[2][6] This species is most often found over the upper continental slope at depths of 270–960 m (890–3,150 ft).[8] It has been caught as deep as 1,300 m (4,300 ft), and a tooth has been found lodged in an undersea cable at a depth of 1,370 m (4,490 ft).[27] Adults inhabit greater depths than juveniles. Immature goblin sharks frequent the submarine canyons off southern Japan at depths of 100–350 m (330–1,150 ft), with individuals occasionally wandering into inshore waters as shallow as 40 m (130 ft).[2][28] On 19 April 2014, fishermen in Key West, Florida, 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.[29] The shark was photographed and released back into the water.[29] The first shark found in the Gulf was caught by commercial fisherman on 25 July 2000 at a depth of approximately 919-1,099 m (3,016-3606 ft) and is thought to have been about 20 ft long.[30]
During July 2014, a goblin shark was found in a fishery net in Sri Lanka, near the eastern coast of Sri Lanka. The shark was about 4 ft (1.2 m) long and weighed about 7.5 kg (17 lb). The shark was given to the NARA (National Aquatic Resource Research & Development Agency) for further research.[31]
Although observations of living goblin sharks are scant, its anatomy suggests its lifestyle is inactive and sluggish.[32] Its skeleton is reduced and poorly calcified, the muscle blocks along its sides (myomeres) are weakly developed, and its fins are soft and small. Its long caudal fin, held at a low angle, is also typical of a slow-swimming shark. The long snout appears to have a sensory function, as it bears numerous ampullae of Lorenzini that can detect the weak electric fields produced by other animals. Due to the snout's softness, it is unlikely to be used for stirring up prey from the bottom as has been proposed.[9] Vision seems to be less important than other senses, considering the relatively small optic tectum in the shark's brain.[6] Yet unlike most deep-sea sharks, it can change the size of its pupils, thus probably does use its sight in some situations.[27] Goblin sharks may be the prey of blue sharks (Prionace glauca).[28] Parasites documented from this species include the copepod Echthrogaleus mitsukurinae,[33] and the tapeworms Litobothrium amsichensis and Marsupiobothrium gobelinus.[34]
The goblin shark feeds mainly on teleost fishes such as rattails and dragonfishes. It also consumes cephalopods and crustaceans, including decapods and isopods. Garbage has been recorded from the stomachs of some specimens.[35] Its known prey includes bottom-dwelling species such as the blackbelly rosefish (Helicolenus dactylopterus), and midwater species such as the squid Teuthowenia pellucida and the ostracod Macrocypridina castanea rotunda. Thus, the goblin shark appears to forage for food both near the sea floor and far above it.[9][36]
Since it is not a fast swimmer, the goblin shark may be an ambush predator. 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.[28] 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.[8] At the same time, the well-developed basihyal (analogous to a tongue) on the floor of the mouth drops, expanding the oral cavity and sucking in water and prey.[9] Striking and prey capture events were videotaped and recorded for the first time during 2008 and 2011 and helped to confirm the use and systematics of the protrusible jaws of goblin sharks. The video evidence suggests that while the jaws are definitely unique, goblin sharks use ram feeding, a type of prey capture that is typical of many mackerel sharks.[37] 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.[37] This “slingshot” style of feeding could be an adaptation to compensate for poor swimming ability by allowing the goblin shark to catch elusive, fast prey without having to chase the prey.
Little is known about goblin shark reproduction because a pregnant female has yet to be found and studied. It likely shares the reproductive characteristics of other mackerel sharks, which are viviparous with small litter sizes and embryos that grow during gestation by eating undeveloped eggs (oophagy).[2] The birth size is probably close to 82 cm (32 in), the length of the smallest known specimen.[6] Males mature sexually at about 2.6 m (8.5 ft) long, while female maturation size is unknown.[2] No data is available concerning growth and aging.[6] Some researchers have estimated, based on their own research and prior findings, that male goblin sharks mature at approximately 16 years old and can live up to 60 years.[38]
Some of the first known findings pertaining to the goblin shark were published in 1910, and the researcher wrote that, "the new shark is certainly grotesque," and that, "the most remarkable feature is the curiously elongated nose."[39] Given the depths at which it lives, the goblin shark poses little danger to humans. 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.[8][40] Its economic significance is minimal; the meat may be dried and salted, while the jaws fetch high prices from collectors.[2][8] At one time, the Japanese also used it for liver oil and fertilizer.[41] This shark is not targeted by any fisheries, but is occasionally found as bycatch in bottom gillnets and trawls, hooked on longlines, or entangled in fishing gear. Most captures are isolated incidents; one of the few areas where it is caught regularly is off southern Japan, where around 30 individuals (mostly juveniles) are taken each year. A black scabbardfish (Aphanopus carbo) fishery off Madeira also takes two or three goblin sharks annually. 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. The species had never been recorded in the area before, nor has it been found in such numbers since.[2][6] The International Union for Conservation of Nature (IUCN) has categorized the goblin shark as Least Concern.[2] In addition to its wide range, most of its population is thought to reside in unfished environments because few adults are caught. Therefore, it is not believed to be threatened by human activity.[2] However, 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.[42]
The goblin shark (Mitsukurina owstoni) is a rare species of deep-sea shark. Sometimes called a "living fossil", it is the only extant representative of the family Mitsukurinidae, a lineage some 125 million years old. This pink-skinned animal has a distinctive profile with an elongated, flat snout, and highly protrusible jaws containing prominent nail-like teeth. It is usually between 3 and 4 m (10 and 13 ft) long when mature, though it can grow considerably larger such as one captured in 2000 that is thought to have measured 6 m (20 ft). Goblin sharks are benthopelagic creatures that inhabit upper continental slopes, submarine canyons, and seamounts throughout the world at depths greater than 100 m (330 ft), with adults found deeper than juveniles. Some researchers believe that these sharks could also dive to depths of up to 1,300 m (4,270 ft), for short periods of time.
Various anatomical features of the goblin shark, such as its flabby body and small fins, suggest that it is sluggish in nature. This species hunts for teleost fishes, cephalopods, and crustaceans both near the sea floor and in the middle of the water column. Its long snout is covered with ampullae of Lorenzini that enable it to sense minute electric fields produced by nearby prey, which it can snatch up by rapidly extending its jaws. Small numbers of goblin sharks are unintentionally caught by deepwater fisheries. The International Union for Conservation of Nature (IUCN) has assessed it as Least Concern, despite its rarity, citing its wide distribution and low incidence of capture.
