Green Sea Turtle (Chelonia mydas)
The Green Sea Turtle (Chelonia mydas) is a sea turtle found in tropical and subtropical coastal waters worldwide, listed Endangered on the IUCN Red List.
- Common name
- Green Sea Turtle
- Scientific name
- Chelonia mydas
- Conservation status (IUCN Red List)
- Endangered
- Habitat
- Tropical & subtropical coastal waters worldwide
- Edition
- TT-01: First Light
The ultimate zen vegan. Named for the color of their fat, not their shell. They can hold their breath for five hours by slowing their heart rate to one beat every nine minutes.
It is Turtle Tuesday edition TT-01, “First Light”, drawn by hand and free to download.
This drawing is one of the 26 in Color the Shell, the Turtle Tuesday turtle coloring book: the same line art in black and white, with one true fact per turtle.
The ultimate zen vegan. Eats only seagrass and algae, sleeps on the ocean floor, and radiates ‘I have nowhere to be, ever.’ Unbothered. Unhurried. 150 million years of this vibe.
Named for the color of their fat, not their shell. They can hold their breath for five hours by slowing their heart rate to one beat every nine minutes. One beat. Every nine minutes. 150 million years of evolution, and they chose salad and naps over everything else. Respect.
The Original Vegetarian
Green sea turtles are the only sea turtle that goes fully herbivorous as an adult, switching to seagrass and algae around age 3 to 5. The green said ‘nah, I’m going plant-based.’
Their name comes from that diet, not the shell: chlorophyll from all that seagrass turns their body fat green. 'Green Sea Turtle’ is literally named after its insides.
Adult females return to the exact beach where they hatched, sometimes over 1,400 miles across open ocean, probably navigating by Earth’s magnetic field and ocean currents. A turtle born on Ascension Island swims to Brazil to feed, then back to nest.
Conservation is a bright spot: populations in Hawaii, Florida, and parts of the Indo-Pacific have recovered significantly after decades of beach protection. Still endangered globally, but the trend is upward.
Key Moments
- ~150 million years ago: Sea turtle ancestors predate T. rex by 80+ million years
- 1700s to 1800s: Heavy harvesting across the Caribbean shrinks populations
- 1978: Listed under the U.S. Endangered Species Act
- 2004: Archie Carr refuge records its highest nest counts in decades
- 2016: Hawaii’s population shows strong recovery
Fun Facts
- Only Veggie Sea Turtle: Only sea turtle fully herbivorous as an adult
- Green Fat, Not Shell: Named for their green body fat, from chlorophyll in their diet
- One Beat Per Nine Minutes: Slows heart rate to one beat per nine minutes, enabling 5-hour breath holds
- Beach GPS: Females navigate 1,400+ miles to nest on their hatching beach
- Seagrass Mower: Its grazing keeps seagrass meadows trimmed and healthy, like mowing a lawn
- Comeback Kid: Hawaiian and Florida populations have recovered significantly
On the Red List
- On average, about 30,000 female green turtles come ashore to nest each season at Tortuguero, Costa Rica, NOAA Fisheries reports.
Mini FAQ
Why are they called 'green’ if they’re not green?
Green on the inside: all that seagrass turns their body fat green from chlorophyll.
How do they hold their breath for 5 hours?
By slowing their heart rate to about one beat every nine minutes, cutting oxygen use enough to sleep on the seafloor.
How do they find their birth beach?
They likely imprint on their natal beach’s magnetic and chemical signature, then navigate back by Earth’s magnetic field.
Are they actually recovering?
In some regions, yes, Hawaii and Florida especially, though globally they’re still endangered.
Art by Lee Eisenbarth, CC BY 4.0: how to use this art.
Sources: IUCN Red List, Wikipedia.