The Short Answer: Tadpoles eat algae and aquatic plant leaves and stems when they are young, then add more and more protein like insects, insect larvae, and small fish as they mature.
What Are Tadpoles?
Tadpole is the catch-all term for a larval or immature amphibian. This means that a tadpole can grow up to become a toad, a frog, a newt, a salamander, or a caecilian.
Amphibians are unique, cold-blooded animals that generally spend their first life stages in water as tadpoles, then become terrestrial or land-dwelling after maturing into adults.
Fun Fact: Tadpoles are also known as polliwogs.
For the purpose of this article, tadpoles will refer to the immature amphibians of the Anura order (frogs and toads) unless otherwise stated.
There are 6,482 species of tadpoles in the Anura order, and they range in size from 1-4 inches depending on the species. Tadpoles generally live in bodies of freshwater like ponds, lakes, rivers, and creeks.
They can also be found in some unique areas like the Jerdon’s tree frog – whose tadpoles live in the water that collects in the hollows of trees. Some species even grow inside their mother before being ‘birthed’ as mature adults.
Tadpoles live on all continents except Antarctica, and they have adapted to their own environments. For example, in some species of tree-dwelling frogs, the eggs will be laid in the tree on its leaves, and after the tadpole hatches, it will drop into the water below.
Tadpoles can be found in a wide range of water temperatures, from 40 degrees Fahrenheit up to 85 degrees. They tend to grow the best when the temperature is between 65-75 degrees, and most species will time their mating and reproduction with favorable changes in water temperature.
Fun Fact: Even though there are no tadpoles on Antarctica today, a 40-million-year-old frog fossil was discovered there.
Tadpoles are characterized by many features that adult frogs and toads lack, but there is a wide variety in how they develop and what exact structures they have.
Almost all tadpoles have broad tails and short, rounded bodies with internal gills that are hidden by an operculum, or a fleshy covering. Their anatomy changes as they mature and all tadpoles start as eggs.
The eggs are generally laid in water by an adult female, and when they hatch 6-21 days later, the tadpoles are small and delicate. Many species will attach themselves with a cement gland, or a specialized sticky structure, to floating grasses or weeds in the water for the first 7-10 days of their life before they begin to forage for food.
Once tadpoles detach and swim freely, they will spend most of their time searching for food. The tadpoles of some species are social and will swim in schools, while others are more solitary.
The operculum will cover the gills of tadpoles by four weeks, and between 6-9 weeks, they start undergoing other transformations as they mature. Limb buds will sprout from the rear first, then slowly elongate.
This is followed by front leg formation while the tail shortens in a process known as apoptosis. Apoptosis is another name for programmed, intentional cell death, and is responsible for many developmental changes in animals.
By 12 weeks on average, the limbs will be completely formed, and only a short tail stub will remain, and lungs will have also developed to replace the gills. Once the lungs have formed enough, you can actually see tadpoles coming up to gulp air from the surface. Between 12 and 16 weeks, they will show semi-terrestrial behaviors, meaning they dwell both in the water and on land before leaving the water altogether as mature adults.
Fun Fact: Only one species of tadpoles, Barbourula kalimantanensis, never develops lungs and instead absorbs oxygen through its skin. This is also true for many tadpoles of salamander and newt species, and one species of caecilian: Atretochoana eiselti.
Many creatures will prey on tadpoles, including humans in some parts of the world. Several species each of fish, birds, and larval water insects all use them as a food source, and in extreme cases tadpoles will even cannibalize each other.
In order to avoid predators, tadpoles will generally use whatever plant life is around when they are hatched to provide cover and protection.
What Do Tadpoles Eat?
Tadpoles are voracious eaters and are primarily herbivorous when they first hatch – meaning they live off of plants and plant matter. As they grow, they tend to become omnivores, meaning they will also start eating animals like insects and small fish.
This does not apply to all species of tadpoles – some are also scavengers meaning they will eat dead animals and some are even strictly carnivores, meaning they will catch and eat the meat of other animals as their only food source.
How Do Tadpoles Get Their Food?
In their first 7-10 days after hatching, tadpoles will mostly eat the remaining yolk sac that is leftover from their eggs. Once that’s gone, they will search the area where they hatched for algae since they are too small to eat much else.
Very young tadpoles will also occasionally eat decaying plants, but they prefer to eat algae. As they get bigger, tadpoles can start to search for and eat plant matter and other aquatic vegetation.
As tadpoles mature further, they become able to hunt, eat, and digest smaller animals and insects. They may travel farther to find more varied food sources, or stick to the area where they hatched.
What Do Young Tadpoles Eat?
As mentioned, very young tadpoles do not have to forage for food because they can use their yolk sac, which is rich in protein and other nutrients, to sustain them. Once that runs out, they will start eating algae.
These tadpoles are not picky about the kinds of algae they eat, and they usually do not have to venture far from the area they hatched. They may also nibble on decaying plants and grasses.
Larger tadpoles will eat the leaves and stems of plants, and their digestive systems are optimized to get as much nutrition as possible from this herbivorous diet.
In captivity, young tadpoles can be fed commercially available tadpole food or pellets, or they can eat the algae and plants in your tank like hornwort. You can also offer tadpoles foods like lettuce and leafy greens, but these are better used as treats since most don’t have enough nutrients to sustain their growth initially.
It is important to note that tadpoles will sometimes refuse to eat without a place to hide, so providing adequate shelter for your tadpoles is just as important as providing food and high-quality water. It is also important to note that, just like in the wild, tadpoles do not need to be fed for the first 7-10 days of their life.
What Do Older Tadpoles Eat?
As tadpoles mature, their digestive tracts shorten, and they become more easily able to digest meat and animal matter. They will often catch and eat insects and insect larvae like water striders, and many species will also scavenge dead insects.
Like their mature versions, tadpoles will eat anything that they can catch and fit into their mouths, including small fish, but most species will not cannibalize each other unless food is extremely scarce.
In captivity, older tadpoles can eat a wide range of foods, from raw veggie chunks to aphids, bloodworms, dead insects, and insect larvae. As tadpoles start to develop legs (between 6-9 weeks), they will need a more substantial amount of protein, and eventually they will become entirely carnivorous adults.
You can also feed commercial tadpole food in larger quantities, but just make sure that you don’t give them any protein sources they wouldn’t encounter in the wild like chicken, beef, etc. They won’t be able to digest it well.
What Do Adult Tadpoles (Frogs/Toads) Eat?
The exact diet of frogs and toads varies by species – sometimes widely – but all of them are carnivores. Smaller adults will eat insects like mosquitoes and flies, while larger adults will eat insects like worms and grasshoppers.
Some of the largest frogs and toads will even eat mice, snakes, other amphibians, and baby turtles. Overall, size is the most significant determinant of an adult’s diet followed by location, and most will eat any animal or insect that they can fit into their mouth.
What Do Other Kinds of Tadpoles Eat?
Salamander tadpoles are carnivorous, eating small freshwater microorganisms like cyclopsen or daphnia. As they mature, they will eat larger daphnia, then later insect larvae and tubifex worms like sludge worms.
By the time salamander tadpoles are two months old, they are eating the same diet as the adults. This can range from worms to maggots and other insect larvae to the insects themselves, like crickets and flies.
Newt tadpoles are also carnivorous and will eat microworms like nematodes to start. Then they will move on to larger animals like brine shrimp, daphnia, and small worms like whiteworms and grindle worms.
As tadpoles mature, they will move on to larger worms like blackworms, tubifex worms, and bloodworms, and adults will eat worms, slugs, insects, and small invertebrates.
Caecilian tadpoles, unlike others, feed predominantly on plankton until they mature. These large, worm-like amphibians then become burrowers and feed on worms, insects, lizards, snakes, and frogs.
Fun Fact: Caecilians swallow their food whole.
Tadpole Food Options
Your tadpoles can thrive on a wide variety of foods, as long as they are fed the ones most appropriate for their life stage.
Vegetables (fresh or boiled)
Fish food flakes
Egg yolk (hard-boiled)
The Tadpole Digestive System
Tadpoles consume food through their mouths, and the species that have teeth chew it into small pieces. It passes down the diverticulum, the tadpole version of an esophagus, to their stomach.
In the stomach, the food is ground down and digested into its smallest nutrients and parts, and then it passes into the intestines where the nutrients are absorbed. The intestines of tadpoles are long and coiled – ideal for extracting nutrients from an herbivorous diet, and as the tadpole matures, its intestines shrink and condense into the short form that is best suited to digesting meat.
Once the nutrients have been absorbed in the intestines, the remainder is expelled from the cloaca as feces. The cloaca is the common opening of the digestive system, urinary tract, and reproductive tract in birds, amphibians, and fish.
How Often Should I Feed My Tadpoles
Tadpoles younger than five weeks should have constant access to plants and algae, but make sure that you don’t have too much algae in the bottom of the tank (more than one layer thick). Tadpoles will devour everything they can once they finish their yolk sac, so making sure to limit the algae will keep them from becoming obese.
As with any captive environment, the goal is to mimic their natural habitat as much as possible. Once tadpoles are older than five weeks, you can start introducing various protein sources and harder veggies in meals, generally two per day.
Tadpoles with legs should be given more and more protein on a meal-fed basis compared to plants, and make sure that you clean out any excess or uneaten food regularly to maintain your water quality.
Summary of What Tadpoles Eat
Tadpoles are the immature life stage of amphibians and can refer to a larval frog, toad, salamander, newt, or caecilian.
Tadpoles in the order Anura grow up to be frogs and toads, and they start off eating their yolk sac once they hatch.
After the yolk sac is finished young tadpoles will eat algae and soft plant matter, then graduate to plant leaves and stems.
Older tadpoles who are sprouting limbs will eat protein as well from insects and their larvae, dead insects, and small fish.
In captivity, making sure you feed tadpoles a diet that is appropriate for their life stage is essential to helping them grow.
Mature tadpoles (frogs and toads) leave the water, using their newly developed lungs to breathe, and are entirely carnivorous.