Animals That Eat Algae

Written by: Akeem Eletu
Last updated on:

This article has been reviewed by veterinarian Sara Ochoa

What Animals Eat Algae?

One of the fascinating things about algae is that they are not plants, even though they have chlorophyll and other necessary pigments for performing photosynthesis. They grow in saltwater oceans, freshwater lakes, and other waterways at a depth of the photic layer where the sun reflects and penetrates through the water. 

Algae feed on the waste of decomposing materials and waste of marine animals. Also, the growth of algae largely depends on the photosynthesis process. But what animals eat algae?

Here is an illuminating piece that discusses animals that eat algae and some benefits of eating algae.

Do Animals Eat Algae?

Yes, some animals eat algae in case you have been wondering what animals eat algae. In addition to phytoplankton, algae form the bases of aquatic food webs.

Also, primary consumers like small fish, crustaceans, and zooplankton enjoy eating algae. Many young marine animals like frogs, fish, and aquatic insects eat algae as their primary food source.

There are various types of algae, and they vary in colors, such as red, blue, and green. You will often find algae in water where it forms gooey mats. Algae may look unattractive and less desirable when you look at it, but these animals treat it as a delicacy whenever they get some. 

What do algae eat? Algae are not animals, so they don’t need food to survive or multiply because they get their nutrients and energy from sunlight. 

Algae are essential to the ecosystem because they help provide oxygen to living things via photosynthesis. Incredibly, they contribute up to 50% of oxygen in the atmosphere, which humans and other organisms utilize. 

There is a whole lot more to algae than just food for animals. Even though they aren’t plants, algae are effective fertilizers for growing crops. The list of the benefits and functions of algae for living organisms on earth is almost endless.

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What Animals Eat Algae?

Different species of aquatic consumers eat algae. Algae serves as a source of protein, many vitamins, and minerals for animals. It also serves as a source of prebiotics, especially for ruminant animals. Below is a list of animals that love algae.


Algae grow in freshwater. So it is only natural for some fish species like Kuhli loach, Hillstream loach, Chinese algae eater, Octocinclus, Siamese algae eater, and Bristlenose pleco to eat algae. These fish species live in freshwater and depend on algae as a source of food.

Octocinclus eat biofilms and algae, growing and gathering on rocks and plants. Although hillstream loaches eat algae, they don’t solely depend on it as a food source. The diet of this fish species needs to be supplemented with other nutritious and high-quality meals to enhance their growth and development.

Unlike other fish, the Plecostomus is a collection of fish that are omnivores. This group of fish includes all sizes of suckermouth catfish. Plecos don’t have a specific diet as they can get nutrients by feasting on foods like wood fiber, fish food, shrimps, algae, thawed frozen foods, and insects. They have a long list of menus they can pick from whenever they feel like it. But they love and feast on algae when they get the chance.

Also, the Chinese algae eater feasts on algae that form on plants and rocks. Chinese algae eaters are small distinct sucker-mouthed fish that can eat algae as much as possible, even with their sucker-mouth.


Mollusks prefer green algae because it is a simple and available food source. Limpets, Chitons, Abalone, and the common whelk are examples of mollusks that frequently eat algae.


There are various snail species you can find in freshwater. They include Apple snail, Sun snail, Rabbit snail, Malaysian trumpet snail, Ramshorn snail, and Nerite snail. These snails eat algae.

These snails have an essential role in the aquarium or the wild freshwater. They maintain the tank (or the freshwater bodies) and ensure that dead plants, fish, algae, and other detritus don’t remain in the tank or pond. 

They scavenge these waste materials and ensure they are recycled and eradicated correctly. Snails are a good maintenance choice for your aquarium if you wish to keep the algae in check.


Shrimps are also a perfect example of algae eaters that live in freshwater. Shrimps are omnivores that will eat anything ranging from plankton to algae. There aren’t selective animals, so they can conveniently eat all types of algae. 

Shrimps will even eat alga that grows on hard surfaces in the tanks or ponds. Ghost shrimp, Bee shrimp, Amano shrimp, Sulawesi cardinal shrimp, Grass shrimp, Bamboo shrimp, Cherry shrimp, and Snowball shrimp are notable algae eaters.

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Sea Urchins

Sea urchins usually live in colder, offshore waters. They have a structure of five rigid plates called Aristotle’s lantern that comes together like a beak. With this mouth, they can scoop up algae for feeding whenever. 


Although crabs are omnivores, this does not stop them from eating algae when the opportunity arises. The sally lightfoot crab and the common mithrax are two common types of crabs that eat algae the most. 

Crabs usually dwell beneath the ocean floor, coral reefs, and rocks because they are in search of food. They scavenge for organic matter, waste, carcass, and algae in the water, and their claw makes the eating and hunting process manageable and easy.


Tadpoles are young or baby frogs. They are too young to follow the same staple meals as mature frogs. Tadpoles are herbivores that survive on soft plants like moss, duckweed, and algae. The diet to follow depends on their species. But they all like algae at that young age and depend on algae as the primary source of feed for the first few weeks of their existence. 

Final Thoughts

While some eat all algae types (the green algae: Chlorophyta, the brown or golden-brown algae: Phaeophyta, and the red or purple bacteria Rhodophyta), others are specific and demanding in the type of algae they eat.

Other Animals that eat algae include centipedes, salamanders, Antarctic krill, Bluegills, Sea Cucumbers, Sora, Gadwall, Coot, Scoter, and turtles (like the Midland painted turtles, wood turtles, red-eared sliders, sea turtles), etc. So when next the question “what animals eat algae?” crosses your mind, be sure to check back on this article for a fairly exhaustive list.

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