Olive Sea Snake
Some of the deadliest hunters in the world are found in our oceans. Not all of them are what you might expect, either. From creatures the size of a baseball to leviathans weighing 45 tons, the animals featured here are all among the deadliest to their prey – and occasionally to man, too.
Sperm whale surface fishing with Tuna in its mouth
Some use razor sharp teeth to slice up their prey; others use electricity, venom, or simple speed and stealth. The end result, however, is the same: swift death – from hunters that have specialized senses and body parts to track down and tackle their prey.
12. Great Barracuda
The great barracuda is the biggest of all the barracuda species and is built like a torpedo. A solo hunter, it hunts in the shallows and around coral reefs, and has incredible vision with which it can either ambush or chase prey down. Officially, only two humans have been killed by barracudas, but they are suspected in many other deaths.
11. Sperm Whale
The massive sperm whale is as long as a subway car and eats around a ton of food a day. Its favorite food is the giant squid – which lives in the depths of the ocean, 900 meters down – as well as fish and octopus. The sperm whale has teeth up to 20 cm long for shredding its prey.
The sperm whale finds its prey using echolocation. It generates a high-pitched ultrasonic click from the front of its head that bounces off its target. This returns to the whale, which interprets it – much as a submarine does – to determine the location of the squid or other animal. Exactly what happens when the sperm whale reaches its prey is clouded in mystery, but scientists know it involves some struggle from the huge suction cup marks found on the whales' skin.
10. Bull Shark
Bull sharks are named for their solid appearance and are deadly to their prey. They have small eyes and so use a specialized sense of smell instead when hunting. They also have tiny gel-filled organs in their head for sensing the electromagnetic current of their prey from a distance. Swimming at top speed, they race to their prey and kill them with rows of saw-like teeth (which are continuously replaced). Some scientists believe the bull shark attacks humans more than the great white.
9. Torpedo Ray
The three animals listed above all used their razor sharp teeth to kill, while the next three rely more on shock, stealth and speed. The torpedo ray looks like a stealth bomber but uses electric shocks as its weapon. It is one of 14 ray species that deliver such shocks and its power comes from a disk in the middle of its body. It traps fish beneath itself, folding its wings down around its victim and issuing a strong shock that at least stuns and normally kills its prey. The torpedo ray hunts in shallow waters, where divers are often present, and if alarmed can deliver a 50 volt shock, which is why many unexplained drownings are thought to be due to this fish. The current from the torpedo ray can cause cardiac arrest in people, and potentially death.
Billfish are known for their hunting speed. The family includes sailfish and marlin, but the sailfish are the fastest fish in the ocean. Unfortunately they are also popular trophy and food fish. Overfishing and habitat destruction have reduced their numbers by 90%.
Billfish have killed humans who have them on a line with one of their mighty leaps in an effort to escape: the sword-like nose can pierce fishermen's bodies. When it comes to hunting, sailfish flare their fins to look larger than they are and work together as a team to push schools of fish together. Then they use their swords as bats, stunning and maiming the fish for an easy dinner.
7. Leopard Seal
The leopard seal uses stealth to take down its prey. It is the only seal which feeds primarily on warm-blooded animals: penguins form 80% of its diet, an average of five birds a day per seal. Their 2 1/2-cm canines cut through the penguins like butter, and the seals don't just take them in the ocean...
Leopard seals will also go on land to hunt their prey, although some penguins have been known to escape by playing dead. In such cases, the seal then lets it go to get a better grip and the bird escapes. Unfortunately for the penguins, the leopard seal is one of the most ferocious hunters in the ocean and rarely misses its prey.
6. Olive Sea Snake
Sharp teeth, speed and surprise are not the only tools for hunting in the ocean; venom can also kill, and among the most venomous animals on earth is the olive sea snake. It is the most toxic snake in the ocean, with one bite said to be able to deliver enough venom to kill 20 full-grown men. The small hollow fangs contain two different toxins: a neurotoxin that affects the nerves and a myelotoxic affecting the tissue, which combined can cause a swift death. The olive sea snake has a good sense of smell and also has a hidden extra weapon to call on. In its tail there are light-sensitive nerve cells that pick up the reflections of fish, giving it another set of "eyes". Danger for scuba divers occurs when the snake goes up to the surface to breathe and back down again, crossing paths with the divers.
5. Fire Sea Urchin
The fire sea urchin not only has venom; it can also bite. The size of a baseball or smaller, it is still one of the deadliest creatures in the ocean. It injects its venom in two ways: its spines contain venom sacs, with the venom able to be injected directly into the wound through the spine; but it also has dozens of tiny jaws that snap shut on prey and inject the paralyzing toxin into its victim. These attractive but deadly urchins have killed humans before, and there is no antivenom. So watch where you step!
4. Box Jellyfish
The biggest known venomous killer of humans in the sea is the box jellyfish. It has killed upwards of 80 people in Australia alone in the past 50 years and is the most toxic jellyfish there is. The box jellyfish also actively hunts rather than just drifting along until prey appears, unlike true jellyfish. Another notable feature of the box jellyfish is its sets of eyes, which function very like human eyes. They can have around 60 tentacles with thousands of stinging cells with which to inject their venom into their prey, and that can cause complete cardiac and respiratory arrest in humans.
3. Killer Whales
The killer whale is a giant member of the dolphin family, able to reach 4,500 kg, or 10,000 pounds, in weight. Killer whales live in pods of up to 40 and work together to track and hunt prey. Herding schools of fish into a ball, they swipe their mighty tails to stun the fish, making them easy pickings. They will also hunt like a pack of wolves and take out porpoises and seals, biting with their 10 cm-long teeth. All in all, they may look adorable, but they are one of the most vicious predators in the sea, so no trying to pat them from a boat!
2. Great White Shark
The great white! This fish can kill people, make no mistake, and has done so many times, mostly off the coast of Australia, though in other parts of the world's oceans as well. Between 18 and 25% of its brain is devoted to smell, while gel-filled canals on its face that look like black dots, called the ampullae of Lorenzini, pick up the electric stimuli given off by potential prey. The great white's massive size – it weighs 1,500 to 2,400 pounds – and razor sharp teeth make it a formidable hunter. It is also a predator that is difficult to evade, with its preferred hunting method being ambush from below. Great whites prefer to eat fatty mammals for the energy they provide, and in a study one shark rejected a sheep carcass entirely when given the choice between it and the carcases of a pig and a seal. Great whites are not fish to be messed with – yet they won't attack indiscriminately. It is believed that they bite humans because often they look like seals from below, especially if paddling on a surfboard.
1. Salt Water Crocodile
Our final entry in this list of the ocean's deadliest hunters is the salt water crocodile. Another massive animal, it is the largest reptile on earth and has existed unchanged for 60 million years. A confirmed man-eater, it is 900 kg of pure muscle. Glands on its tongue allow it to expel the salt of the ocean although actually it rarely lives in the ocean, preferring rivers, swamps and tributaries. When it hunts its quarry, it explodes on them, twisting and rolling to kill, and uses its 60 or so sharp teeth to shred flesh and break through bone.
Almost all of the hunters listed here have attacked at least one person or have a human fatality to their name, and all are the deadliest ocean hunters to their prey. Whether they hunt alone, in teams, or wait for prey to come to them, the end is the same: a swift and merciless death.