What the species is and where it came from
Chelonia mydas is a large sea turtle of the family Cheloniidae. It is the only species in its genus. It lives in tropical and subtropical seas worldwide — Atlantic, Pacific and Indian Oceans.
How it works, in terms someone would actually use
It migrates long distances between nesting beaches and shallow coastal seagrass meadows. It feeds exclusively on seagrasses as an adult. Its green fat — not its shell — gives it its name.
What it gets right
It reliably occupies shallow lagoons where seagrass grows. It sustains genetically distinct Atlantic and Pacific populations. It is the only species in the genus Chelonia.
What it does not
It does not eat jellyfish, crustaceans or fish as an adult. It does not inhabit deep pelagic zones year-round. It does not have a global endangered status: the IUCN lists it as ‘least concern’ globally in 2025.
What it changed
It redefined dietary specialisation among marine reptiles. No other aquatic turtle species is herbivorous as an adult.
Who it is for, and who it is not
It is for marine ecologists studying herbivory in oceans, conservationists tracking regional subpopulations, and divers who can access shallow seagrass meadows. It is not for those seeking novelty in behaviour beyond migration and grazing, or for anyone expecting data on lifespan, clutch size or population trends — none are provided in the sources.
Is it worth your time
Yes, if you want to see the only fully herbivorous aquatic turtle. No, if you expect to observe it feeding in deep water or outside tropical and subtropical lagoons.
