of . 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 . 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. The shark was photographed and released back into the water. 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. 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 long and weighed about . The shark was given to the NARA (National Aquatic Resource Research & Development Agency) for further research. Biology and ecology Although observations of living goblin sharks are scant, its anatomy suggests its lifestyle is inactive and sluggish. 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. Vision seems to be less important than other senses, considering the relatively small optic tectum in the shark's brain. Yet unlike most deep-sea sharks, it can change the size of its pupils, thus probably does use its sight in some situations. Goblin sharks may be the prey of blue sharks (Prionace glauca). Parasites documented from this species include the copepod Echthrogaleus mitsukurinae, and the tapeworms Litobothrium amsichensis and Marsupiobothrium gobelinus. Feeding 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. 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