Hammerhead Sharks in Galapagos

You can find them abundantly in the islands of: Wolf, Bartolome, Santa Cruz and in the arch of Darwin island.

Sharks are a protected species in the Galapagos Marine Reserve and are present in large numbers at close range to divers.

The marine highlights hold a unique feature for Galapagos: the only place on Earth that has tropical water fish, subtropical water fish, sea lions and even penguins.

Diving experiences will definitely create a sense of adventure accomplishment, and many will speak about them for years to come, more so if it was their first time ever with hammerhead sharks, white-tip reef shark, and the colossal whale shark

Most of the hammerheads are very social animals. These sharks have long been scientifically investigated. Their oddly-shaped heads make them very recognizable.

Scientists have wondered about the function of the odd-shaped head. Do they have greater maneuverability, can they smell better or is their vision enhanced because of their long head lobes?

The nine known species of hammerhead sharks range from 2–6 m long, and all species have projections on both sides of the head that give it a resemblance to a flattened hammer.

Great hammerhead sharks posses a virtually straight anterior margin of the head with a deep central indentation. They have high second dorsal fins and the pelvic fins have curved rear margins.

The teeth are triangular with extraordinarily serrated edges, becoming increasingly oblique toward the corners of the mouth.

Their coloration varies from deep olive green to brownish grey above and white below.

Hammerheads are found in warmer waters such as the the coastal waters of Galapagos.

They are aggressive predators which eat fish, rays, other sharks, cephalopods, and crustaceans.

Hammerheads are one of the most highly evolved types of shark. The wide separation of the eyes gives superior vision.



The front of the head between shark's eyes is spanned by sense organs which detect changes in pressure and electrical field. In the case of hammerheads, the width of the head makes these senses more acute than those of other sharks. The head also acts as a wing, improving maneuverability.

The hammer shape of the head was once thought to act as a wing, aiding in close-quarters maneuverability, allowing sharks to execute sharp turns without loss of stability. But it was found that the special design of its vertebra allowed it to make the turns correctly, more than its head.

It also seems to help in electro location by separating the receptors, thus giving hammerhead sharks a wider area of search. These sharks have been able to detect an electronic signal of half a billionth of a volt.

The hammer shaped head also gives these sharks larger nasal tract, increasing the chance of finding a particle in the water by at least 10 times as compared to other classical sharks.

Hammerheads have proportionately 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 lonely hunters.

Reproduction in the hammerhead shark occurs once a year and each litter contains 12–15 pups. Hammerhead shark mating courtship is a very violent affair. The male will bite the female until she acquiesces, allowing mating to occur.

Unlike many other shark species, the hammerheads have internal fertilization which creates a safe environment for the sperm to unite with the egg. The embryo develops within the female inside a placenta and is fed through an umbilical cord, much like in mammals. The gestation period is 10–12 months. Once the pups are born the parents do not stay with them and they are left to defend for themselves.

There are two schools of thought for the odd head shape of the hammerheads. One states that it is because of the greater area for sensors to scan the bottom of the sea floor for food and the other that it provides lift and added maneuverability.

Both of the theories are probably correct. Geneticist Andrew Martin used DNA to study all hammerhead species and he concluded that the first hammer appeared on the wing head shark which have the largest hammer and the rest of the hammerheads evolved one at a time from the original Winghead shark each with a smaller hammer.

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