A sea turtle is a marine mammal that belongs to the Chelonioidea superfamily and Panchelonioidea clade.Sea turtles were initially land animals that adapted to aquatic life due to the abundance of food found in water sources. They evolved 150 million years ago.A sea turtle has a spindle-shaped body. Unlike land turtles, a sea turtle’s head, limbs, and tail are not retractable. These body parts are simply attached to the shell. There are seven sea turtle species and there are around 6.1 million sea turtles in the world. However, the number of sea turtles is constantly decreasing due to habitat loss and poaching. Other reasons for this population decline is commercial harvesting for food, eggs, jewellery, and leather. Sea turtles are cold-blooded animals, which means their metabolism rate is affected by temperature changes in the environment. A sea turtle’s metabolic rate slows down when the temperature is cold, and when the temperature is hot, it increases rapidly. This creature spends a lot lot time underwater. Though a sea turtle cannot breathe underwater, it will still survive in aquatic systems as it can hold its breath when it is underwater. A sea turtle is also called a marine turtle. A sea turtle can reach 950 ft (290 m) underwater or even deeper when it is searching for food.How do sea turtles hold their breath for so long?Sea turtles have a bunch of unique features that help them live in marine environments. Apart from spending time on land when they lay eggs, they spend most of their time in the water.These reptiles do not possess gills which are essential in order to live underwater. They do not breathe underwater. Instead, they hold their breath. Living while holding your breath most of the time is definitely not an easy task, but it comes naturally for sea turtles!Some species of sea turtles can easily absorb oxygen from water. They do this by using their cloaca, which is a cavity present at the end of their genitals. This cavity is also found in many other vertebrates and invertebrates. Turtles have nostrils, also known as external nares. They are present right above the mouth. Sea turtles conveniently use this to get air without actually coming to the surface of the water body. They simply have to get close enough to expose their nostrils. Some species of sea turtles also hibernate underwater. At such times, they solely depend on their cloaca. They do not need much oxygen anyway as their metabolic rate drops and locomotion is reduced when they are sleeping. The skeletal, respiratory, and muscular systems are also built in such a way allowing them to go on without air for prolonged periods when compared to other animals and humans. Sea turtles use their muscles and blood to store more oxygen. Sea turtles reduce their heart rate to conserve oxygen. There can be a gap of nine minutes between two heartbeats.How often do sea turtles need to breathe?How often sea turtles need to breathe depends on several factors such as age, species, swimming speed, and health of turtles.In general, during winter seasons while they are hibernating, they only need air once every seven hours. When sea turtles are swimming, they need to get air every 30 minutes depending on the activity. Sea turtles can go without breathing for 4-7 hours if they are resting or sleeping. Despite being able to hold their breath for a maximum of 40-45 minutes, they normally come to the surface every 5-10 minutes. This is because sea turtles do not like to push their limit. They may drown if they remain underwater for several hours. This might happen due to unforeseen events. For instance, sea turtles lose their oxygen quickly when they are under stress. Sea turtles can also use up the oxygen in their bodies when they are trying to escape predators. This will result in high levels of lactic acid which are toxic to sea turtles. Some turtles are also bad at swimming and fail to rush to the top at the last minute. They always come up every few minutes to get air.How do turtles use the butt breathing technique underwater?Turtles actually use their butt to breathe! This might sound funny and disgusting at the same time, but this is a tactic used by sea turtles to survive and, in a way, it is actually mind-boggling.Cloacal respiration is a unique way of breathing that some animals use. This type of respiration is used by many other animals, reptiles, and even birds. While the colloquial term is butt breathing, the technical term is cloaca respiration. This type of respiration is quite different from normal respiration. Turtles have an opening at the end of their genitals. This is an endpoint of the digestive tract and the urinary tract. Turtles use this to excrete urine and faeces. Sea turtles will suck water in through the cloaca by contacting its muscles. This water then reaches the cloacal bursae, which is a major site of aquatic respiration. Bursae are similar to our lungs. They are a set of unique tissues which separate oxygen and expel unnecessary hydrogen. These pouch-like structures are lined by thread-like structures called fimbriae, where gas exchange occurs. They also have a pair of air bladders. These bladders will absorb oxygen from the water. External respiration and intestinal respiration are other names of cloacal respiration.Eastern painted turtles are one of the many turtles that use cloacal respiration. They are dependent on this method when they hibernate. Toxins are secreted when the oxygen levels are lower in their blood. These turtles absorb calcium that is present on their shells to balance the toxins. The white-throated snapping turtle is an Australian species that also relies on the oxygen that comes from its cloacal bursae. Fitzroy river turtles get 70% of their oxygen from cloacal respirationDo turtles sleep underwater?Several turtle species sleep underwater. Water is one of the safest places for turtles and many other animals to rest.Sea turtles like the leatherback turtle, Olive Ridley, Kemp’s Ridley, and green sea turtle spend most of their time in the water, so it is natural for them to sleep underwater. Marine turtles have mastered the art of holding their breath for prolonged periods. All they have to do is take one long breath before they go to sleep. These turtles generally sleep on ocean beds and in coral caves. Their metabolic rate also falls when they go to sleep, helping them conserve more oxygen.Freshwater turtles sleep at the bottom of lakes and along river beds. They are quite similar to sea turtles. Some species of freshwater turtles can stay underwater for several months at once. These turtles not only stay underwater, but they also live under the sand. They tend to bury themselves under the sand.A majority of aquatic turtles sleep on the surface of the a water body when they are in deep waters.Why do sea turtles come to the surface of the water?Sea turtles typically come to the surface of the water to catch their breath. The body of a turtle lacks gills. It depends on its nostrils, lungs, and cloaca to hold its breath underwater.A turtle can neither breathe underwater nor hold its breath forever. In order to stay underwater, it needs to replenish its oxygen every. sooften. Sea turtles come to the surface after they dive for 5-10 minutes to get air. A sea turtle will take two or three long breaths before going in for another dive. If sea turtle does not come to the surface, its oxygen supply will eventually be cut off, resulting in death. This short period that a turtle spends on the surface of the water is crucial for its existence. Some sea turtle species also come to the surface to sleep.Is pollution affecting turtles’ breathing abilities?Most sea turtle species, especially green turtles and Kemp’s ridley turtles, are endangered. There are several factors that have contributed to the decline in population. Pollution is one of the major factors that affects the breathing abilities of a turtle.Pollution affects turtles in many ways. A particular type of tumour, fibropapillomas caused by ocean pollution, involves the growth of tumours in a turtle’s internal and external organs. When tumours grow around the mouth, it creates difficulty in breathing and feeding. There have been multiple incidents in which turtles with plastic objects stuck in their throats have been found dead. When plastic or any other pollutant gets stuck in the nasal cavity, it affects the breathing capacity of turtles. This is life-threatening for sea turtles as they stay underwater for prolonged periods. This might cause suffocation and anaphylaxis. Oil spills in water also impair their ability to breathe. Most turtles that remain underwater use cloaca respiration. When the pump in water contains toxic oil, it will not only slow down their respiration but can also be life-threatening.Did You Know…The leatherback turtle which gets its name from the leathery shell is the largest sea turtle in the world. It is also an exceptional diver. This turtle can dive up to 3000 ft (1000 m) deep. Another interesting fact about the leatherback turtle is that it mainly feeds on jellyfish.While studying female sea turtles of most species, scientists found that a vast number of females who are nesting go back to the same beach where they were born. During the nesting season, females can lay around 110 eggs. Sea turtles have to make a trip to the shore to lay their eggs. A female sea turtle will carefully lay her eggs in a chamber and cover the eggs with sand.There is a turtle nesting beach in Texas. Biologists in this area have provided ways to raise these young turtles in optimal conditions as they are prone to predation. Once the hatchlings are large enough to survive on their own, they are then released from the turtle nesting beach.When the water temperature drops and becomes extremely cold, turtles are washed by the waves to the shore in a state called cold stunned. They are unable to move in this condition. They float and reach the shores.The turtle that can remain underwater for the longest duration is the loggerhead turtle (Caretta caretta). It is a sea turtle species that can stay underwater for a period of 10 hours while all the other sea turtle species can only stay underwater for a period of seven hours or a little longer.
A sea turtle is a marine mammal that belongs to the Chelonioidea superfamily and Panchelonioidea clade.
