乐生活Sphyrna tiburo
The smallest living hammerhead shark, with a maximum body length of 1.5m and a maximum body weight of 10.8Kg, is found only in the West Atlantic Ocean. It ranges from North Carolina to the southern coast of Brazil. It usually inhabits offshore waters with a depth of 10-80m. It often swims on sandy seabed, muddy seabed and seagrass bed, usually forming 2.- There are 15 small groups of activities, but there are also records of hundreds of large groups. It is worth noting that this species is the only shark known to have plants in its natural diet. The quality of seaweed accounts for 62.1% of the total stomach volume. A study in 2018 showed that its digestibility of organic matter in seaweed is as high as 50 +2%. Cellulose degrading enzymes even exist in the hindgut, which indicates that narrow-headed hammerhead sharks can eat seaweed. The head width ratio of the narrow-headed hammerhead shark is the narrowest among all the hammerhead sharks, and the recognition degree is very high. Narrow-headed hammerhead shark is a typical viviparous fish. Its gestation period may be the shortest known shark, only 4.5-5 months. After gestation, females will produce 4-12 larvae of about 30-33 cm in length. The delivery period is usually in late summer and early autumn. In May 2007, through the study of captive hammerhead shark, scientists found that this species can be carried out. Parthenogenesis.
IUCN currently assesses this species as LC. Narrow-headed hammerhead shark is the only endangered species of hammerhead shark family. It is an important fishing and fishery species in its distribution. In the eastern coast of the United States, the catch of narrow-headed hammerhead shark accounts for about 50% of all small sharks. Narrow-headed hammerhead sharks occasionally bite when threatened, but their aggressiveness is not strong, so they are often raised and exported as ornamental fish. In recent years, more and more narrow-headed hammerhead sharks have begun to flow into the mainland’s aquarium market.
