Goblin shark

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 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 brought it to Jordan. Jordan named the shark Mitsukurina owstoni in honor of these two men. The common name "goblin shark" is a calque of its traditional Japanese name , , a tengu| being a Japanese mythical creature often depicted with a long nose and red face. Another name for this species is elfin shark. Soon after Jordan's description was published, several scientists noted the similarity between Mitsukurina and the extinct Mesozoic shark Scapanorhynchus. 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. 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. ==Phylogeny and evolution==

Phylogenetic studies based on morphology have classified the goblin shark as the most basal member of the order Lamniformes, known as mackerel sharks. Studies using genetic data have also confirmed a basal classification for this species. 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); 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. 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". ==Description==

The goblin shark has a distinctively long and flat snout, resembling a blade. The proportional length of the snout decreases with age. Until 2022, the maximum weight recorded was for a shark of in length, ==Distribution and habitat==

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. A single eastern Pacific specimen is known, collected off southern California. This species is most often found over the upper continental slope at depths of . It has been caught as deep as , a tooth has been found lodged in an undersea cable at a depth of . It has been sighted as deep as . Adults inhabit greater depths than juveniles. Immature goblin sharks frequent the submarine canyons off southern Japan at depths of , with individuals occasionally wandering into inshore waters as shallow as . ==Biology and ecology==

Although observations of living goblin sharks are scant, its anatomy suggests an inactive and sluggish lifestyle. 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 detect 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. ==Human interactions==

As a deep-sea species, the goblin shark poses no danger to humans. After David Starr Jordan described the shark in 1898, more findings were published in 1910. "The new shark is certainly grotesque, [...] the most remarkable feature is the curiously elongated nose." A few specimens have been collected alive and brought to public aquariums, though they only survived briefly. One kept at Tokai University lived for a week, while another at Tokyo Sea Life Park lived for two days. ==References==