The Hammerhead Shark

Posted by on 06/17/2011

 

“The nine known species range from 0.9 to 6 m (3.0 to 20 ft) long and weigh from 500 to 1000 pounds. They are usually light gray and have a greenish tint to them. Their bellies are white which allows them to be close to the bottom of the ocean and blend in to sneak up on their prey.[2] Their heads have lateral projections which give them a hammer-like shape.

Costa Rican hammerhead shark

It was determined recently that the hammer-like shape of the head evolved to enhance the animal’s vision.[3] The positioning of the eyes 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.[4] 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. However, it was found that the unusual structure of its vertebrae was instrumental in making the turns correctly, more often than the shape of its head, though would also shift and provide lift. 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 pores called ampullae of Lorenzini. By distributing the receptors over a wider area, hammerheads can sweep for prey more effectively.[5] These sharks have been able to detect an electrical signal of half a billionth of a volt. The hammer also allows the nostrils to be placed farther apart, increasing its ability to detect chemical gradients and localize the source.

Hammerheads have disproportionately small mouths and seem to do a lot of bottom-hunting. They are also known to form schools during the day, sometimes in groups of over 100. 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 when a hammerhead is in shallow waters or close to the surface for long periods.[6]

tutie to be positioned wider apart, this aids the fish in determining the direction of a given scent. It is a stereo smell that is based mainly on timing of scent detection, rather than relative intensity [7][8].”

 

Source: http://en.wikipedia.org/wiki/Hammerhead_shark

 

One Response to The Hammerhead Shark

Leave a Reply

Your email address will not be published. Required fields are marked *

*

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

FACEBOOK
Adventure Journal is Proudly Designed By Contexture International