Step into the extraordinary world of sea turtles with our exclusive handbook, the ‘Unparalleled Handbook on Sea Turtles’. Within these pages, you will discover a treasure trove of captivating sea turtle trivia, mesmerizing visuals, and enlightening knowledge.
Navigate through the menu provided to unearth the precise facts you seek, or simply embark on a mesmerizing journey of discovery by scrolling down and delving into the depths of sea turtle expertise!
Sea Turtles Facts: Introduction
There exist seven distinct types of sea turtles, each with its unique characteristics. These remarkable creatures inhabit various oceans worldwide, predominantly thriving in tropical and subtropical waters.
Within this page, you will uncover comprehensive information regarding sea turtles. Delve into their classification as a specific animal species, explore the diverse types of sea turtles, and delve into their ancient origins on Earth, hinting at their remarkable age.
Moreover, you will discover the captivating life cycle of sea turtles, wherein certain species embark on incredible journeys spanning thousands of miles annually.
What Is A Sea Turtle?
A sea turtle is a reptile that inhabits the sea. It possesses a protective shell and has evolved its four limbs into flippers for swimming. Unlike land turtles, sea turtles are unable to retract their head and flippers into their shell for defense.
While sea turtles need to surface to breathe air, they have various adaptations that enable them to spend extended periods underwater. Consequently, sea turtles spend the majority of their lives beneath the surface.
Sea turtles are ectothermic creatures, meaning they lack internal mechanisms to regulate their body temperature. Unlike warm-blooded mammals, they cannot sweat to cool down or shiver to warm up.
The leatherback sea turtle, due to its large size and insulation, can maintain a body temperature higher than its surroundings. This has led some scientists to believe that the leatherback may be endothermic, like warm-blooded animals.
Sea turtles are oviparous, laying eggs that hatch outside the female’s body. They lay their eggs on land, with females only returning to the shore for this purpose. Once hatched and making their way into the sea, male sea turtles never return to land.
As marine creatures, sea turtles consume a significant amount of saltwater. They eliminate the excess salt from their bodies through salty tears produced by specialized glands near their eyes.
Sea Turtle Shells
A sea turtle possesses a shell comprising two primary components:
- The upper portion, known as the carapace, safeguards the sea turtle’s back.
- The lower portion, referred to as the plastron, shields the sea turtle’s underside.
The rigid scales composing the sea turtle’s shell are called scutes.
Sea Turtle Family And Related Animals
In the realm of sea turtles, there exist two distinct families. The first is Cheloniidae, housing the majority of these aquatic reptiles with six out of the seven known living species. The second family is Dermochelyidae, which consists solely of the leatherback sea turtle, the sole survivor of its lineage.
All seven sea turtle species, regardless of their family affiliation, belong to the superfamily Chelonioidea.
Sea turtles, along with their land-dwelling counterparts, tortoises, turtles, and terrapins, are classified under the order Testudines, encompassing the diverse group of reptiles that roam the world’s lands and oceans.
How Long Have Sea Turtles Been Around?
Sea turtles have graced our planet for an incredibly long time. These reptiles with their protective shells made their first appearance approximately 220 million years ago, during the late Triassic Period of the Mesozoic era.
While marine turtles emerged during the late Jurassic period, the lineage from which our present-day sea turtles descended can be traced back to the Cretaceous Period.
One of the earliest known ancestors of the sea turtles we see today is a remarkable creature called Desmatochelys padillai. This ancestor emerged over 120 million years ago, during the early Cretaceous period.
It’s truly astonishing to realize that sea turtles have been swimming in our oceans since the age of dinosaurs! In fact, they existed even before the late Cretaceous dinosaurs, such as the mighty T. Rex, made their appearance.
Types Of Sea Turtle
In our discoveries, we have come across seven distinct types of sea turtles that belong to two separate families. Now, allow me to introduce you to each of them…
Family Cheloniidae
Among the Cheloniidae family reside six out of the seven sea turtle species found today. Distinguishing characteristics of these remarkable creatures include their durable carapaces.
Flatback Sea Turtle
Officially known as Natator depressus, this intriguing creature’s scientific name sparks curiosity. However, its conservation status remains a mystery. With limited data available, experts have been unable to determine the level of concern for this species.
The flatback sea turtles inhabit the shorelines of Australia and New Guinea. They have a unique nesting behavior, exclusively choosing the beaches in northern Australia as their nesting grounds.
Unlike many other sea turtle species, they don’t embark on extensive journeys across vast distances. True to their name, flatback sea turtles possess shells that are noticeably flatter compared to their counterparts in the sea turtle family.
Green Sea Turtle
Taxonomic designation: Chelonia mydas
Status in terms of conservation: Endangered
The green sea turtle, known for its impressive size, possesses a notable attribute that sets it apart. Beneath its shell resides a remarkable layer of green fat, from which the species derives its name. Interestingly, the turtle’s shell, typically a dark brown hue, is not the source of this name. As the green sea turtle matures, it undergoes a notable dietary transformation, adopting a predominantly herbivorous lifestyle, exclusively feasting on plants.
Hawksbill Sea Turtle
Official classification: Eretmochelys imbricata
Status of conservation: Critically Endangered
Hawksbill sea turtles possess distinctive, curved beaks resembling those of hawks. They also have a unique characteristic—a serrated, saw-like edge at the back of their shells. Sadly, these turtles are targeted for their shells, sought after for the creation of a decorative substance known as “tortoiseshell.”
Kemp’s Ridley Sea Turtle
Kemp’s Ridley turtles hold the title of being the most uncommon sea turtles on the planet, and nearly half a century ago, they teetered on the edge of extinction. When the nesting season arrives, a remarkable sight unfolds as thousands of female Kemp’s Ridley sea turtles simultaneously emerge from the sea.
This extraordinary phenomenon, where they gather en masse to lay their eggs, is referred to as an ‘arribada’.
Loggerhead Sea Turtle
Taxonomic designation: Caretta caretta
Conservation classification: Vulnerable
Loggerhead sea turtles can be encountered across the globe. They possess distinguishable traits like their substantial heads and robust jaw muscles. Among sea turtles, the loggerhead species vies with the green turtle for the position of the second-largest. However, the leatherback sea turtle takes the crown as the largest sea turtle on Earth.
Olive Ridley Sea Turtle
Olive Ridley turtles are petite marine turtles adorned with olive-green shells. They dwell in the vast expanses of the Pacific and Indian Oceans. Despite their plentiful presence, these turtles are considered vulnerable in terms of conservation. Similar to their close relative, the Kemp’s ridley sea turtle, the olive ridley also displays the remarkable phenomenon of mass nesting.
Family Dermochelyidae
Leatherback Sea Turtle
Species Name: Dermochelys coriacea
Conservation Classification: Vulnerable
The solitary representative of the Dermochelyidae family, the leatherback sea turtle, stands as a remarkable creature. It holds the title of being the largest sea turtle species and ranks as the fourth-largest reptile on our planet.
Distinguishing itself from its relatives in the Cheloniidae family, the leatherback possesses a shell with a unique characteristic. Its shell exhibits a relatively softer composition, akin to leather, but maintains a durable and resilient texture.
Where Do Sea Turtles Live?
Sea turtles can be found across the globe, with a higher concentration in tropical and subtropical waters, while they tend to steer clear of the colder Polar Regions.
When it comes to nesting, sea turtles choose the warm sands of tropical and subtropical beaches. Many sea turtle species embark on remarkable journeys spanning hundreds of miles annually, as they navigate between their feeding habitats and the places where they lay their eggs.
Among these remarkable travelers, the leatherback sea turtle takes the crown for covering the most extensive distance. In fact, there was an instance where a single leatherback turtle journeyed a staggering 20,000 kilometers (12,000 miles) over a span of nearly two years.
What Do Sea Turtles Eat?
Sea turtles, a diverse group of creatures, have a wide-ranging taste when it comes to their meals. They are known to be omnivorous, enjoying a mix of plant and animal food. Their menu includes seagrasses, seaweed, sponges, mollusks, jellyfish, and various other marine organisms.
Each sea turtle species has its own unique dietary preferences. The leatherback sea turtle has a special fondness for jellyfish, while the hawksbill turtle primarily dines on sponges. Interestingly, the green sea turtle stands out as the only species that is almost entirely herbivorous. During its adult life, it mainly feasts on seagrasses and algae.
How Big Are Sea Turtles?
Sea turtles are creatures of considerable size. Among them, the leatherback stands out as the largest, with a shell that spans about 1.75 meters (5.7 feet) in length, taking into account its curved shape.
On the other end of the scale, we have the olive ridley sea turtle, which is the smallest of its kind. This species typically measures around 60 centimeters (2 feet) in length.
Sitting in the middle are the medium-sized sea turtles, like the hawksbill. These turtles reach approximately 1 meter (3 feet) in length and have an average weight of 80 kilograms (180 pounds).
How Long Do Sea Turtles Live?
Sea turtles are creatures with impressive longevity, taking several decades or even longer to reach maturity in certain species. Despite their remarkable lifespans, there is limited knowledge about the exact duration of their lives. Expert estimates vary, suggesting that sea turtles can live anywhere from approximately 50 years to well over a century.
Sea Turtle Predators
Grown-up sea turtles are mighty and heavily protected creatures. They face limited dangers in their natural habitat, but killer whales, great white sharks, and tiger sharks are their primary adversaries.
However, the tale takes a different turn for baby sea turtles. When they embark on their journey into the ocean, these young turtles become targets for various predators. Depending on the location, they may fall victim to ghost crabs, coyotes, dingoes, monitor lizards, and countless seabirds.
Sea Turtle Life Cycle
The remarkable journey of sea turtles begins as hatchlings emerge from their eggs and navigate their way through the sandy nest. Interestingly, the temperature within the nest influences the gender of the hatchlings, with lower temperatures favoring males.
Typically, sea turtle eggs hatch during the nighttime hours. Guided by their instincts, the young turtles instinctively move towards the ocean. They rely on the moon’s reflected light and the shimmering stars on the water’s surface to find their way.
Once in the open ocean, most hatchling sea turtles allow themselves to be carried by the currents, spending their initial years drifting along, occasionally encountering floating seaweed clusters.
As the turtles mature, they gradually move closer to shore, where they continue to grow until they reach adulthood. At this stage, their migratory lifestyle commences, as they travel seasonally between their feeding and breeding grounds.
Remarkably, sea turtles possess a remarkable sense of navigation, returning to the very beaches where they themselves hatched. For some species, this homing instinct leads them back to their exact place of birth.
Mating among sea turtles occurs in the water. After mating, the females employ their large flippers to heave themselves out of the water and gradually make their way up the beach. Once there, they dig deep holes in the sand to lay their eggs.
The number of eggs a female sea turtle lays varies depending on the species, ranging from 50 to well over 300 in a single clutch. After carefully burying the eggs in the sand, the female returns to the ocean, leaving the incubation process to nature. Throughout the breeding season, she may repeat this nesting ritual multiple times. Interestingly, neither the mother nor the father sea turtle has any involvement in raising their offspring.
Once hatched, male sea turtles remain in the ocean for the entirety of their lives, never setting foot on land again. In contrast, female sea turtles only make their way back to land when it’s time to lay their eggs.
Are Sea Turtles Endangered?
Regrettably, the collective condition of sea turtles is quite concerning. Even the olive ridley sea turtle, which is considered the most populous species, has been classified as vulnerable by the IUCN (International Union for Conservation of Nature).
Out of the six identified sea turtle species with available data, two are in critical danger, one is endangered, and three are deemed vulnerable. (Please refer to the section on sea turtle types for the specific conservation status of each species.)
Threats to Sea Turtles
Sea turtles encounter various perilous challenges. Despite receiving protection from numerous governments, these majestic creatures still face the relentless pursuit of hunters who seek their meat and prized shells.
The dwindling numbers of sea turtles are further exacerbated by the loss of their natural habitats due to coastal development. Construction activities encroach upon nesting beaches and disrupt other coastal areas. Moreover, the issue of light pollution arises, as the presence of electric lights near nesting beaches confuses hatchlings. Instead of following the natural guidance of starlight reflecting on the water, these young turtles become disoriented, hampering their journey to the sea.
Tragically, sea turtles often meet their demise as they become entangled in fishing nets, leading to their drowning.
The detrimental impact of pollution also takes a toll on sea turtles. These magnificent creatures frequently ingest floating plastic, mistakenly perceiving it as food. This consumption of plastic can result in illness and even death for the turtles.