The Life of Animals | Hammerhead sharks | The nine known species range from 0.9 to 6 m (3.0 to 20 ft) long and weigh from 500 to 1000 pounds. The positioning of the eyes, mounted on the sides of the shark's distinctive hammer head pointing outward like a Trex, give the shark good binocular vision, as well as 360-degree vision in the vertical plane, meaning They can see above and below Them at all times. The shape of the head was Previously thought to help the shark find food, aiding in close-quarters maneuverability and allowing sharp turning movement without losing stability.
From what is known about the Winghead shark, it would Appear That the shape of the hammer-head has to do with an evolved sensory function. Like all sharks, hammerheads have electroreceptory sensory ampullae of Lorenzini Called pores. By distributing the receptors over a Wider area, hammerheads can sweep for prey more effectively.These sharks have been Able to detect an electrical signal of half a billionth of a volt. In the evening, like other sharks, They Become solitary hunters.
Hammerheads are one of the Few Animals That acquire a tan from prolonged exposure to sunlight. Tanning Occurs a hammerhead is in shallow waters or close to the surface for long periods. Reproduction Occurs only once a year for hammerhead sharks and usually Occurs with the male biting the female shark shark violently until She agrees to mate with him The hammerhead sharks exhibit a viviparous mode of reproduction with females giving birth to live young. Like other sharks, fertilization is internal with the male transferring sperm to the female through one of two intromittent organs Called claspers.
When the supply of yolk is exhausted, the depleted yolk sac transforms into a structure analogous to a mammalian placenta (Called a "yolk sac placenta" or "pseudoplacenta"), through the which the mother delivers sustenance until birth. There is usually a litter of 12 to 15 pups; except for the which the Great Hammerhead births litters of 20 to 40 pups. The great and the scalloped hammerhead are listed on the World Conservation Union's (IUCN) 2008 Red List as endangered, whereas the smalleye hammerhead is listed as Vulnerable. Shark fins are prized as a delicacy, and overfishing is putting many hammerhead sharks at risk of extinction.
