The whale shark is the largest fish in the world – measuring up to 14 m (46 feet) in length (the size of a school bus). Whale sharks are not whales; they are sharks. They have about 3,000 tiny teeth, but they don't use them for eating. They filter feed on plankton, squid, krill, and fish eggs. With their mouths open, they take in water, filter out food, and release the water back into the ocean. A whale shark’s throat is only the size of a grapefruit. Each whale shark has it’s own unique pattern of spots that can be used to identify it, just like a human fingerprint. Whale sharks prefer warm waters and can be seen off the coasts of Central and South America, south Asia, Africa, and Australia. They can live to be over 100 years old. Whale sharks are an endangered species.
Great White Shark
The great white shark can be found throughout the world’s oceans, mostly in coastal waters. They can grow to a length of 6 m (20 feet). With a streamlined body shape and a powerful tail, they can swim at speeds of over 60km per hour. Humans aren’t on the great white shark’s menu – when a bite happens it’s usually a case of mistaken identity. Great white sharks feed on fish, sea lions, seals and small whales. Great white sharks are ambush predators; they position themselves underneath their prey before swimming up and biting. Their bodies have countershading – darker coloured on top and lighter coloured on their bellies – so that they blend in with their surroundings when viewed from above or below. Their teeth have multiple rows so that any teeth lost can quickly be replaced by those in the rows behind them. Great white sharks can live to be over 70 years old. The great white shark is listed as vulnerable by the IUCN Red List.
The leopard shark is a species of houndshark with distinct markings resembling a leopard’s spots. They grow to an average length of less than 5 feet. Leopard sharks are more active at night than during the day. They live in shallow waters along the Pacific coast of North America. Groups of leopard sharks often follow the tide onto mudflats to forage for worms, clams, crabs, shrimp, octopuses, fish, and fish eggs. Leopard sharks can live to be up to 30 years old.
Starfish are not fish – they’re more closely related to sand dollars and sea urchins. They have no brain and no blood, instead they use filtered sea water to pump nutrients through their nervous system. Starfish have tiny suction cups underneath their arms that they use to move and to grab and hold their food. Their stomachs exit their mouths to digest food and re-enter when they’re done eating. They feed on mollusks including clams, oysters and snails. Starfish can live in many ocean habitats including tidal pools, sea grass, coral reefs, rocky shores, and kelp beds. Some starfish can be found on seabeds 9,000 metres deep. Starfish usually have five arms but there are some species who have up to fifty. Starfish can regrow lost limbs. It takes them up to a year to regenerate an arm. Starfish typically live to be 35 years old.
Lionfish are in the scorpion fish family. They range from 5 to 45 cm in length and have venomous spines which they use for self-defense. Lionfish are predators who consume smaller fish, crustaceans and mollusks. Their stomach can expand up to 30 times its normal volume. Lionfish can dive as deep as 300 meters (10,000 feet) underwater. Lionfish are native to the Indo-Pacific and are an invasive species in the Atlantic and Caribbean. A single lionfish can reduce the populations of juvenile fish on a reef by up to 80% within five weeks. Lionfish can live to be 15 years old.
Oceanic Whitetip Shark
The oceanic whitetip shark is one of the most widely ranging sharks. They live in the open ocean, in warm waters throughout the world. They eat a variety of bony fish and squid. Oceanic whitetip sharks are active both during the day and at night. They have to constantly swim to pump oxygen over their gills, so they never sleep. Oceanic whitetip sharks are classified as vulnerable. They are targeted in commercial fisheries because their long fins are desirable for shark fin soup. There has been a 70% decline in their population numbers.
Sea turtles are one of the most ancient creatures on the planet. They have been around since the time of the dinosaurs; 110 million years ago. Sea turtles are found in all warm and temperate oceans. Their diet includes jellyfish, seaweed, sponges, algae, crabs, shrimp, snails and mollusks. They migrate hundreds of miles between their feeding grounds and the beaches where they nest. Sea turtles will return to the same nesting grounds where they were born. They lay between 70-190 eggs and few survive to adulthood. Sea turtles breathe air but they spend most of their lives in the water. Some species can hold their breath for as long as 5 hours. Six of the seven species of sea turtles are threatened or endangered.
Bull sharks can swim in both salt water and fresh water. They can venture far inland through rivers and tributaries. They prefer the warm, coastal waters of tropical and subtropical seas around the world. They are called “bull sharks” because of their short, sturdy body that resembles a bull. Bull sharks are opportunistic predators who can eat almost anything they find including fish, rays, sea turtles, mammals, seabirds, and even young sharks. They hunt during the day and at night. Bull sharks typically live to be 16 years old. They are classified as near threatened on the IUCN Red List.
The Tiger shark is named for the dark stripes found on juveniles, which fade as they get older. They can grow to be as large as 25 feet in length. They eat almost anything they can find. The stomach contents of tiger sharks have been found to include stingrays, squid, sea snakes, seals, birds, and even license plates and old car tires. Tiger sharks live in tropical and sub-tropical waters throughout the world’s oceans. They are fished for their fins, skin, flesh, and livers. Tiger sharks have low reproductive rates and are listed as near threatened. Tiger sharks can live to be 50 years old.
Zebra sharks live in the Tropical Western Pacific, Indian Oceans, and the Red Sea. Zebra sharks are nocturnal. At night, they hunt for crustaceans, mollusks, and small bony fish. They use their flexible bodies to wriggle into crevasses on the reef where their prey is hiding. During the day, they rest on the sea bottom. Zebra sharks grow to a length of about 8 feet (2.5 m). They can live to be over 28 years old. Zebra sharks are endangered.