What do turtles eat?

The facts in one table

Sources: NOAA Fisheries · NOAA Fisheries · NOAA Fisheries

The diet depends on which turtle you mean

Sea turtles are the clearest illustration of how far apart turtle diets can be. Green turtles crop seagrass meadows and algae and keep those meadows productive in the process, which is why they are treated as a grazing species rather than a predator. Leatherbacks are built for a diet of jellyfish and other gelatinous animals, which is also why floating plastic bags are so dangerous to them. Hawksbills take sponges from reef faces, a food almost nothing else can digest.

Freshwater and land turtles widen the picture further. Many pond turtles are opportunistic omnivores that take insects, snails, fish and aquatic plants, while tortoises are land grazers that live on leaves, grasses and flowers. If you are asking about an animal in a tank at home rather than one in the sea, the answer is set by the species you have, not by the word "turtle".

Sources: NOAA Fisheries · NOAA Fisheries · NOAA Fisheries · RSPCA

Young turtles eat differently from adults

NOAA describes young green turtles in the open ocean feeding on the plant and animal life found in drifting communities such as pelagic Sargassum, rather than grazing seagrass the way adults do. The switch to a plant-dominated diet happens when the animal moves into coastal foraging grounds. Population matters too: NOAA notes that the East Pacific population tends to eat more animal prey than other green turtle populations, so even within one species the diet is not fixed.

Source: NOAA Fisheries

Turtles kept at home

For aquatic pet turtles the RSPCA describes a varied diet built on a quality dried food for the species, with thoroughly defrosted freshwater fish, live invertebrate foods such as river shrimp and bloodworm, live plants like pondweed, and cuttlefish bone as a source of calcium. It also warns that these animals are opportunistic feeders that will overeat if allowed to, which is why it recommends feeding every two days and only as much as the animal clears in about five minutes, removing what is left.

Two problems come up often enough to be worth naming. The first is feeding one single food, which the RSPCA warns against because of the build-up of toxins; the second is vitamin A deficiency, which is linked to eye problems and is the reason beta-carotene-rich vegetables are recommended. Species and age change the right answer, so the diet for the animal in front of you is a question for a veterinarian who sees reptiles.

This page describes what the animal eats in the wild and, where relevant, in human care. It is general information, not a consultation: if an animal is unwell or has eaten something it should not have, consult a veterinarian.

Source: RSPCA

What most people get wrong

• "Turtles are herbivores." Only some are, and only at some ages. Among sea turtles the green turtle is the mainly plant-eating exception, not the rule.
• "Lettuce is a complete diet." It is not: a single food is exactly what the RSPCA warns against for pet turtles, and calcium and vitamin A are the usual casualties.
• "Sea turtles eat jellyfish." Leatherbacks do. Hawksbills eat sponges and green turtles graze seagrass — mixing them up is how wrong feeding advice spreads.

Sources: NOAA Fisheries · NOAA Fisheries · NOAA Fisheries · RSPCA

Frequently asked questions

What do green sea turtles eat?

NOAA Fisheries describes adults as primarily herbivores eating mostly seagrasses and algae, with sponges and other invertebrates taken as well.

How long do sea turtles live and how big do they get?

For the green turtle NOAA gives an adult length of 3 to 4 feet (about 0.9–1.2 m) and a weight of 250 to 400 pounds (about 113–181 kg), with a lifespan that is unknown but estimated at 70 years or more.

Can I feed a wild turtle I found?

No. Feeding wild animals changes their behaviour and can harm them, and a turtle out of place may be sick or injured. Contact a licensed wildlife rehabilitator or a veterinarian instead.

Do baby turtles eat the same food as adults?

Often not. NOAA describes young green turtles feeding in drifting open-ocean communities such as Sargassum, and only moving to a seagrass-dominated diet once they reach coastal foraging grounds.