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Green sea turtle

life science Maturity 11-13 Next article →

The green sea turtle, known scientifically as *Chelonia mydas*, is a massive marine reptile. It is the only species within the genus *Chelonia*. These turtles are found in tropical and subtropical seas across the globe. They are vital members of their ocean ecosystems. Many people call them black sea turtles or Pacific green turtles. In Hawaii, they are called *honu* and symbolize luck and long life.

Green Sea Turtle Swimming in the Galápagos
Green Sea Turtle Swimming in the Galápagos

What makes this turtle unique is its diet. Most sea turtles are carnivores, meaning they eat meat. However, the green sea turtle is mostly herbivorous when fully grown. This means it eats plants, specifically various species of seagrass. This diet creates a unique physical trait. The turtle develops green fat beneath its carapace, which is its upper shell. This greenish fat is why we call them green sea turtles. Their actual shells are usually olive to black in color.

Green Sea Turtle grazing seagrass
Green Sea Turtle grazing seagrass

The anatomy of *Chelonia mydas* is perfectly suited for life in the water. They have a dorsoventrally flattened body, which means they are flattened from top to bottom. Their large, teardrop-shaped carapace is made of specific parts. It features five central scutes, which are bony plates, and four pairs of lateral scutes. On the underside, they have a plastron with four pairs of inframarginal scutes. They also possess large, paddle-like flippers for swimming. Unlike the hawksbill turtle, the green sea turtle has a very short snout and an unhooked beak.

Taxidermy of turtle shell (Chelonia mydas)
Taxidermy of turtle shell (Chelonia mydas)

These turtles follow a complex life cycle involving long migrations. Adults often live in shallow lagoons to feed on seagrass. They travel great distances between these feeding grounds and specific hatching beaches. Female turtles crawl onto beaches at night to dig nests and lay eggs. Once the eggs hatch, the tiny hatchlings scramble toward the ocean. In the wild, these turtles can live for up to 90 years.

PMNM - sea turtle hatchlings (28128852695)
PMNM - sea turtle hatchlings (28128852695)

Scientists have a long history of studying these animals. Carl Linnaeus first described the species in 1758 as *Testudo mydas*. In 1868, Marie Firmin Bocourt named a group *Chelonia agassizii* to honor Louis Agassiz. This was later found to be a misspelling or a different name for the same species. Researchers eventually determined that these were not separate species. They are all part of *Chelonia mydas*. A 1993 study also helped clarify how the genus *Chelonia* relates to other marine turtles.

Green sea turtles are quite large and vary in size. They are the second largest sea turtles in the United States. An average mature turtle has a carapace length of about 100 centimeters. They can also reach very high weights. Some exceptional specimens have even reached much larger measurements. They live in coastal areas in more than 140 different countries. They have nesting sites in over 80 countries around the world.

Baby Chelonia mydas 20060319
Baby Chelonia mydas 20060319

The species is divided into distinct genetic populations. There are two major groups: the Atlantic and the Indo-Pacific. One group lives in the Atlantic and Mediterranean seas. The other group lives in the Pacific and Indian Oceans. These groups are separated by the southern tips of Africa and South America. Because there are no warm waters to travel through, they remain isolated. This isolation has caused them to develop different types of mitochondrial DNA.

Green turtle nesting sites
Green turtle nesting sites

Despite their importance, green sea turtles face many dangers from human activity. They were listed as endangered by the IUCN and CITES until 2025. In some places, they are still hunted for food. Pollution can harm them both as individuals and as a whole population. Many turtles die after becoming caught in fishing nets. Additionally, real estate development on coasts can destroy the beaches they need for nesting. Many countries now have laws to protect them and their habitats.

Green turtle nesting tracks
Green turtle nesting tracks
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🖼️ Images & Media (22)
File:Chelonia.svg
Chelonia.svg
File:Taxidermy of turtle shell (Chelonia mydas).jpg
Taxidermy of turtle shell (Chelonia mydas).jpg
File:Green turtle nesting sites.svg
Green turtle nesting sites.svg
File:Chelonia mydas is going for the air edit.jpg
Chelonia mydas is going for the air edit.jpg
File:Karettschildkroete 01.jpg
Karettschildkroete 01.jpg
File:Green Sea Turtle Swimming in the Galápagos.jpg
Green Sea Turtle Swimming in the Galápagos.jpg
File:Green turtle Chelonia mydas is basking on Punaluu Beach Big Island of Hawaii.jpg
Green turtle Chelonia mydas is basking on...
File:Green turtle in Kona 2008.jpg
Green turtle in Kona 2008.jpg
File:Green Sea Turtle grazing seagrass.jpg
Green Sea Turtle grazing seagrass.jpg
File:Baby Chelonia mydas 20060319.jpg
Baby Chelonia mydas 20060319.jpg
File:Green turtle nesting tracks.jpg
Green turtle nesting tracks.jpg
File:PMNM - sea turtle hatchlings (28128852695).jpg
PMNM - sea turtle hatchlings (28128852695).jpg

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