Scalloped Hammerhead Shark – Sphyrna lewini

Laugh at my head again and I’ll beam you up.

The first time you lay eyes on a hammerhead shark will be something you remember forever; their flattened T-shaped heads, their protuberant eyes, that strange mouth at the bottom all make for perfect alien/sci-fi fodder.

The surprising thing is that they’re not even all that alien. Our perception of sharks is shaped by what we see in movies and TV shows, meaning that every time we think of one, our mind draws up the image of the Great White Shark. But there are over 400 species of sharks and hammerheads are one of the most common, found worldwide near warm coastlines and continental shelves.

Hammerhead distribution.

“I feel you”

The scalloped hammerhead is the most commonly found species of hammerheads, with eyes located at the sides of their heads. While their eyes give them a pretty impressive range of vision, their true prowess lies in the fact that they can sense electrical fields to increase their searching abilities when hunting prey. This is done via their sensory organs called the ampullae of Lorenzini on their heads. While all sharks possess this sensory organ, the wider surface area of the hammerheads’, er, heads, contributes to keener sensitivity. They can locate prey buried within the ocean floor, even by a heartbeat.

My eyes see things you don’t.

“Let sleeping dogs lie”

Like most hammerhead sharks, they are not afraid, and also not particularly interested in humans. If your grandparents told you to ‘let sleeping dogs lie’, you should also heed this: ‘let hammerheads be’.  They are potentially dangerous and incidents of human attacks are retaliatory, due to aggression towards them.

You won’t want to be my enemy.

“He ain’t heavy, he’s my brother”

Scalloped hammerhead sharks form very large schools during certain phases of their lives – up to hundreds of them. It can grow up to a length of four metres and a weight of 150 kilograms. Juveniles remain mostly in shallow waters along the shore to avoid danger of falling into the mouths of predators. Upon reaching full maturity, they have little or no natural enemies due to their size, and will venture further out to sea.

They feed mainly on sardines, herrings and mackerels. They also consume smaller sharks such as the Atlantic sharpnose shark and the blacktip reef shark.

Did You Know?

Hammerhead sharks give birth by hatching developed eggs inside their bodies. The eggs are supplied with oxygen and nutrients from the shark’s ‘placenta’ and given birth after 11 months. The placenta is similar in function to that found in humans’.

 

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