Galapagos Shark

“Galapagos sharks are large requiem sharks that reach lengths of 9.8 to 12.1 feet!”

The Galapagos shark belongs to the family Carcharhinidae and falls under the requiem shark species. They give live birth and are migratory, preferring tropical waters.

While their name might indicate that they are only found around the Galápagos Islands, they occur all over the globe. However, they received their name because they were first discovered in what is now the Galapagos Marine Reserve.

Galapagos sharks are one of the biggest of the species and have slender and streamlined builds. They look very similar to the reef shark and dusky shark.

Galapagos Shark Facts

• The Galapagos shark can be found worldwide, mainly around offshore islands and underwater seamounts.
• They are hard to identify from other big requiem sharks because of their similarities.
• They are a dark gray color with an off-white underbelly. They have serrated, triangular teeth on their upper jaw and narrow ones on the lower jaw.
• They are benthic feeders and prefer bottom-dwelling fish and cephalopods. However, the larger Galapagos sharks prey on marine iguanas and sea lions.
• They give live birth in shallow water to a litter of 4 to 16 pups every 24 to 36 months.
• Due to overfishing, their population has dwindled, and the IUCN has listed them as Near Threatened.
• Galapagos sharks are large and grow up to 12.1 feet long.

Galapagos Shark Scientific Name

The Galapagos shark’s scientific name is Carcharhinus galapagensis, but they are also called the grey reef shark or mackerel shark.

The Galapagos shark was first documented in 1905 by Edmund Heller and Robert Evan Snodgrass, and they named it after the location where it was found.

There are eight subspecies which include:

Bignose Shark

The bignose shark has a broad body and is grey in color. It has a pointed nose with significant nostril flaps, which is why it’s called the bignose shark.

It prefers to live offshore and eats smaller sharks, stingrays, and bony fish found on the ocean seabed. Because they don’t often frequent shallow waters, people don’t consider them a threat.

Caribbean Reef Shark

The Caribbean reef shark is predominantly found in the Caribbean, hence the name. Their average features make them hard to distinguish from other requiem sharks, often causing confusion.

They can grow up to 10 feet long and rule their kingdom because of their size and aggressive nature. Divers observed them ‘sleeping’ in caves on the ocean floor, but this behavior is unexplained.

Many Asian countries use shark fins in soup; however, there is concern over eating bignose sharks due to the build-up of toxins in their flesh.

Dusky Shark

Dusky sharks are found all over the world in tropical and temperate waters. They prefer depths of 1,300 feet and usually keep close to the continental shelves and coastal waters.

Dusky sharks’ life spans are incredibly long, and they can live up to 50 years old! However, they only reach sexual maturity at 20 years. And to make matters worse, their gestation periods last 22 months, and their litters generally result in 6 to 12 pups every three years.

Because their reproductive cycle is so slow, and they don’t give birth to many pups, their population rate is very low, and they are listed as Vulnerable on IUCN’s Red List.

The females like to give birth in coastal nurseries along southeast United States, South Africa, and southwest Australia.

Oceanic Whitetip Shark

Oceanic whitetip sharks prefer tropical and subtropical oceans all over the world. They frequent deep water off the coasts but often gravitate to the surface.

They are large with a stocky build, but their most distinctive feature is their pattern of mottled white markings on the edges of their pectoral, dorsal, and tail fins, hence the name. The dorsal fins have rounded tips, and their pectoral fins are paddle-like and long.

Their lifespan is relatively long, and they can live up to 25 years, although there are records of individuals reaching 36 years of age.

The females must wait  6 to 9 years to reach sexual maturity; their gestation period lasts 10 to 12 months, depending on location.

Silky Shark

The silky shark has a slim, large build with a rounded, long snout, big eyes, and small jaws. However, their most defining feature is the tiny, densely-packed dermal denticles.

Females are bigger and reach 7.5 feet, but the maximum length recorded was 11.5 feet;  however, the males measure 6 to 7 feet. As a result, silky sharks can weigh up to a whopping 802.4 pounds.

Their diet consists of:

• Various fish
• Squid
• Pelagic crabs
• Mackerel

They prefer the subtropical waters (about 74°F ) of the Pacific, Indian,  and Atlantic Oceans and are a highly migratory species. They often frequent deep water over water reefs and in the open ocean at depths of 59 to 164 feet.

Females reach sexual maturity between 7 to 9 years of age and males between 6 to 7 years. Silky sharks are viviparous, meaning they give birth to live pups. Their mating season occurs once a year in warm waters during the summer, and gestation lasts 12 months. The average litter size varies by location but is generally 2 to 14 pups. Pups will stay alone in coastal nurseries until winter, when they move to the big open ocean.

Blue Shark

Blue sharks are easily identifiable because of their distinctive blue color and a crisp white underbelly. They have a long conical snout and sleek body and are usually seen at the surface with their dorsal fins peeking out of the water.

Blue sharks are not aggressive but curious and often approach divers and spearfishers, especially when food is involved.

Unfortunately, blue sharks are the biggest victims of overfishing in the world. Did you know that 20 million sharks are caught each year? While they are not specifically targeted, they fall prey to bycatches of longline and driftnet fisheries.

Blue sharks occur in depths of 1,150 feet and prefer tropical waters. While it is not uncommon for them to frequent shallow waters, especially islands where the continental shelf is narrow.

Their gestation period lasts 9 to 12 months, and the females give birth to a litter of 9 to 12 pups. They are viviparous, which means their eggs hatch inside the uterus, resulting in a live birth.

Their closest living relatives are the:

• Dusky shark
• Oceanic whitetip shark
• Blue shark

Galapagos Shark Appearance

The Galapagos shark has a sleek and slender build with two dorsal fins, one on its back and another towards the tail.

They are brownish-gray with a light underbelly and have round, broad snouts with a mouth full of sharp, serrated teeth. Galapagos sharks are massive and reach lengths of 9.8 to 12.1 feet, and can weigh up to 430 pounds

Galapagos Shark Behavior

The Galapagos shark is mostly solitary but also occurs in loose groups. They are very curious animals and will often swim up to divers and spearfishermen, especially if food is involved.

If they feel threatened, they will arch their backs and raise their heads, lowering the caudal and pectoral fins. In addition, they start to swim while rolling and twisting aggressively.

Galapagos sharks are potentially dangerous to humans and could attack if there is a food source close by. So, it is best to avoid swimming in areas where they are present.

Galapagos Shark Habitat

They thrive in shallow water but can reach depths of 919 feet. However, research has shown that Galapagos sharks in the Hawaiian Islands enjoy steep dives and rapid ascents of 2,230 feet.

When they are in shallow water, they prefer areas with strong currents, but scientists cannot explain the reason behind this behavior.

The Galapagos sharks migrate to deeper waters in the open ocean realms in the winter and are often found in large groups.

Astonishingly, some studies have revealed that they account for 90 to 95 percent of various shark species in specific locations.

Galapagos Shark Diet

Galapagos sharks have a wide selection when it comes to prey. They usually eat:

• Octopus
• Squid
• Seals
• Sea lions
• Marine iguanas
• Small sharks

Galapagos sharks are cannibalistic and sometimes eat their young, so the pups stay away from the adults in shallow water.

What Happens When They Eat Something They Shouldn’t?

Galapagos sharks have a unique ability that everyone needs from time to time. If they accidentally consume something poisonous, they can eject the entire contents of their stomach through their mouths.

This allows them to empty their stomachs if needed and rinse it out before sucking it back into their bodies.

Galapagos Shark Predators and Threats

Because of their size, Galapagos sharks have few predators. But, their young are vulnerable to cannibalism. However, most of their decline is due to overfishing and habitat loss (the coastal nurseries).

Most fishermen do not intentionally target the Galapagos shark, but they often get caught in nets. However, some fishermen purposefully kill them because they think they are threats.

In addition, their fins are in high demand in the Chinese market because they use their fins in soup and other body parts in traditional medicine.

Are Galapagos Sharks dangerous?

Yes, Galapagos sharks are dangerous and belong to the group (Requiem sharks) responsible for many attacks on humans.

Because they are curious animals, they often swim up to divers, and if food is involved, they can become quite aggressive. However, if they are met with aggressiveness by divers, they do not shy away. Instead, it makes them more excited.

The International Shark Attack File states that Galapagos sharks are only responsible for one human death in the Virgin Islands.

Galapagos Shark Reproduction, Babies, and Lifespan

The Galapagos shark’s mating season commences early in the year, and their gestation period lasts 12 months. The females often receive “mating scars” because the males bite their fins, gills, and body during the ritual.

They are viviparous, meaning the females carry eggs inside their uterus, which the males fertilize. They hatch inside their mother, and she gives birth to live pups.

Their litters generally consist of 4 -16 pups every two to three years. If they make it to adulthood, it is estimated that they can live for 20-25 years. However, scientists don’t know much about their lifespan.

Galapagos Shark Population

The current population size of the Galapagos shark is unknown. However, the IUCN Red List states they are Near Threatened.

Are there other sharks in the Galapagos Islands?

Yes, the Galapagos Islands are overflowing with wildlife, including a variety of 32 species of sharks. Some species stay put while others migrate.

They include:

• Tiger sharks
• Bullhead sharks
• Galapagos hammerheads
• Whitetip reef sharks
• Whale sharks

Galapagos Shark In the Aquarium

Not many aquariums can house Galapagos sharks due to their size and aggressive nature. However, there is a facility where you can visit them:

• Mandalay Aquarium, Nevada

Can I go Diving With a Galapagos shark?

Although there are not many aquariums where you can see the Galapagos shark, you can go diving with them. Many tours take people scuba diving and snorkeling in the Galapagos Islands.

Darwin Island and Wolf Island are the best places to view them because that’s where the largest population occurs.

As mentioned above, they can be aggressive, and there have been eight shark-related attacks in the Galapagos Islands over the years. “Since records of shark accidents were first recorded in 1854 there have been a total of 8 incidents of sharks in the Galapagos Islands and only 3 involving tourists. Two were tuna fishermen chumming the water in the 1950s, and one of them actually fell overboard into a school of fish! Three were surfers.”

But, if you are adamant about diving with these majestic creatures, ensure you are with an experienced guide. Always be alert and watch out for any suspicious behavior, and if you feel threatened, rather evacuate their space.

1. Florida Museum, Available here: https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/carcharhinus-galapagensis/
2. Wikipedia, Available here: https://en.wikipedia.org/wiki/Galapagos_shark
3. Britannica, Available here: https://www.britannica.com/animal/Galapagos-shark
4. Storyteller.Travel, Available here: https://storyteller.travel/galapagos-shark/
5. Monterey Bay Aquarium, Available here: https://www.montereybayaquarium.org/animals/animals-a-to-z/galapagos-shark
6. Galapagos Conservation Trust, Available here: https://galapagosconservation.org.uk/wildlife/galapagos-shark/
7. Shark Research Institute, Available here: https://www.sharks.org/galapagos-shark-carcharhinus-galapagensis
8. Quasar, Available here: https://www.quasarex.com/galapagos/animals/galapagos-shark#:~:text=Galapagos%20sharks%20are%20normally%20found,from%206%20to%2016%20pups.
9. IUCN Red List, Available here: https://www.iucnredlist.org/species/41736/2954286#taxonomy