Sharks are undoubtedly one of the kings of the ocean. With over five hundred species of shark ranging from the 17 cm (6.7 in) long dwarf lanternshark all the way up to the whale shark that measures up to 12 m (40 ft) in length, sharks are a seriously diverse and exciting animal to study.
We have all heard of the movie Jaws, which sees a great white shark terrorise the tourists staying at a popular holiday resort, and while there are surprisingly few shark attacks directed towards humans each year, what do sharks eat? They have enormous rows of teeth and a carnivorous diet, but do sharks eat turtles?
Do Sharks Really Eat Sea Turtles?
Almost every species of shark is considered to be predatory, with a few species evolving to be able to filter feed on plankton. However, some shark species have taken a liking to hunt sea turtles.
In particular, tiger sharks have developed a taste for sea turtles and seem to hunt them out specifically over other creatures. Great white sharks are another species of sharks that have been found to eat sea turtles.
The smaller the turtle, the more shark species enjoy eating them. Hammerhead sharks, for example, only seem to eat turtles around the size of a small stingray. Sharks such as reef sharks enjoy much smaller prey and, therefore, rarely enjoy eating turtles.
Can A Shark Break A Turtles Shell?
Turtles are known for being protected by a tough and reasonably large shell. This makes them less tasty to many ocean predators, especially when they grow larger, as most predators do not have the biting strength or teeth required to break the shell.
Many species of shark, including tiger sharks, have evolved to have a particular type of tooth that assists in breaking turtle shells. These sharks will grab hold of the sea turtle in their mouths and violently shake their heads from side to side until their teeth are able to break through the turtle’s shell.
Even the skin of a turtle is reasonably tough, so only larger-sized sharks can eat turtles, or they go for much smaller or younger turtles. It is also essential to consider that the bite force of larger sharks is much greater than that of smaller sharks.
This means that larger shark species have no problem breaking through a turtle’s shell, unlike smaller species that struggle quite a bit. There have been reports of a great white shark being strong enough to bite all the way through a turtle’s shell and body with one bite!
Do Sharks Snack On Baby Turtles?
Unfortunately, baby turtles are a high-protein mini snack for almost every shark species. They are small enough for most species to eat easily and have soft shells since hatchling shells do not harden straight away.
Since baby turtles are so easy for more predators to eat, very few make it to adulthood. Baby turtles are pretty defenceless against predators, and it is estimated that between one in every thousand to one in every ten thousand baby sea turtles survive.
Sadly, this is why only seven species of sea turtles remain today, and almost every species is endangered.
How Can A Turtle Protect Itself From A Shark Attack?
Turtles are not fast swimmers, with an average swimming speed of 1.7 – 6.2 mp/h (2.8 – 10 km/h), which does not differ much between species, so swimming away from danger is out of the question. Only the leatherback turtle can swim at a high speed of 22 mph (35 km/h).
If a turtle is about to be bitten by a shark, its best defence is to position itself so its shell takes the damage from the shark’s bite, not its flippers. If a flipper becomes damaged, the turtle will be unable to swim and become easy prey floating defensively.
Turtles also use camouflage to escape predators. Many turtles will bury themselves under sand and deep into the coral reef to avoid being seen by predators. Once a turtle is mature enough, it will be safe from most sharks as it would be too big.
How Much Do Sharks Eat?
The majority of species of shark do not require much food per day. The amount varies between the species and also depends on the shark’s size. Even a few species of shark only eat once every few weeks. When they eat, they consume a substantial meal, and in between meals, they survive off of oil stored in their liver. When the shark’s oil levels get low in its liver, it will have the instinct to go hunting for its next meal.
The circulation of a shark is slowed down. This is because sharks are cold-blooded creatures, and this also means that sharks are not required to eat as much as people think. Their slower circulation rate means their energy is burned much slower.
When the regular food of a shark becomes less readily available, the shark will often adapt to find new food sources. This also affects the amount a shark will have to eat since different prey has different nutritional qualities.
What Other Sea Creatures Does A Shark Eat?
There are many different species of shark, each with its own feeding habits. However, the majority of species of sharks are completely carnivorous. Some species of shark have evolved to be able to consume plankton using a filter-feeding system.
The incredible thing about shark’s diet is that they are exceptionally adaptable. When their preferred food source is scarce, they will adapt to eating whatever they can find in the habitat they are living in.
Shark species are split into two groups:
Carnivorous Sharks
Carnivorous sharks are usually found enjoying a diet of fish, molluscs and crustaceans, with some larger species enjoying larger animals. Larger sharks enjoy consuming creatures like dolphins, seals, sea lions and porpoises and fish such as tuna, mackerel and sometimes smaller species of sharks!
When they can, some species of shark swim up to the surface of the water and snack on unsuspecting sea birds!
Some species of shark appear to be fussier with their food and distinctly prefer eating specific creatures over others. For example, tiger sharks like to snack on turtles, hammerhead sharks enjoy eating rays, and blue sharks seem to like eating squid.
Carnivorous sharks are skilled hunters and fast swimmers with a strong bite force and large teeth. Some predatory sharks have adapted multiple hunting strategies to become more successful. Large species will swallow their prey in one giant bite, but thresher sharks will stun their target using their tails! Saw sharks have a fascinating strategy when hunting. They will catch their prey in their jaws and then swim down to the sea bed, where they twist their snack around in the sand to kill it.
The species of shark which enjoy a habitat at deeper depths, closer to the ocean floor, have adapted to use ambush tactics while hunting. This involves hiding from their prey and sneaking up on them to catch them stealthily. The species that use this tactic will also camouflage themselves within their hunting environment.
There are also other species of shark that feed solely on crustaceans. These sharks kill their prey by crushing them hard against their teeth. Some species of sharks have been observed to hunt in small groups instead of individually. This is more common in smaller species of shark than in larger species. This results in a more successful hunt where they share the end result amongst themselves.
The hunting habits of all species of shark help to preserve a healthy population of the species they see as their prey. Sharks will often prey upon the elderly, injured or sick members of a population, leaving behind the fittest members of the species. For the shark’s prey, it really is survival of the fittest.
Planktivore Sharks
Planktivore sharks are not what comes to mind when you think of sharks. Instead of hunting their prey, planktivore sharks have adopted a filtration system allowing them to suction in water and use long filaments to filter their food through it.
Some larger species of shark prefer to eat plankton than other prey. Whale, basking, and megamouth sharks are all species that prefer dining on plankton to fish!
Planktivore sharks usually have very tiny teeth and prefer to use their filtration system over catching prey with their teeth. Some species can take in up to two million litres of water and only get around two kilograms of plankton from that amount! Planktivore sharks allow a larger volume of plankton to build up before they swallow them.
Technically both kinds of sharks are carnivorous, but they don’t consume a tremendous amount of food. Most sharks will only consume between 0.5 to 3 per cent of their body weight due to their slow digestive system and ability to chew.
Related Article Do Turtles Have Scales?