Chinese Algae Eater – Detailed Guide: Care, Diet, and Breeding

Chinese Algae Eater – Detailed Guide Care, Diet, and Breeding

Chinese Algae Eater (Gyrinocheilus aymonieri) is a renowned freshwater fish in the fishkeeping hobby. They are loved by most aquarists because of their effective role in cleaning up the tank and keeping it algae-free.

Although this is a job they do best at a juvenile stage, their dietary preference alters in favor of meatier and live food as they mature.

Keep reading for everything there is to know about the Chinese Algae Eater, and how to successfully keep and care for this fish in your aquarium.

Quick Notes about Chinese Algae Eater

Name Chinese Algae Eater
Other Names CAE, Sucking loaches, Sucking catfish, Golden algae eater
Scientific Name Gyrinocheilus aymonieri
Tank size (minimum) 30 gallons (~120 liters)
Keeping Easy – Medium
Breeding Hard
Size up to 28 cm (~ 11 inches)
Optimal Temperature 22 – 27 °C (72 – 80 °F)
Optimal PH 6.0 – 8.0 
Optimal GH 5 – 20   
Dwellers Mid and bottom
Nitrate Less than 20
Diet Omnivore
Temperament Semi-aggressive
Life span up to 10 years
Color Form Olive-brown, yellow, albino, marble and leucistic

Origin and Taxonomy of Chinese Algae Eater

The Chinese Algae Eater, Gyrinocheilus aymonieri was first described by Tirant in 1883. It was named after the French linguist and explorer, Étienne François Aymonier. Chinese Algae Eater was first exported to Germany in 1956 for the aquarium trade, prior to that, they were used as a food fish in the native countries.

This species belongs to the genus Gyrinocheilus, and includes other species: Spotted Algae Eater Gyrinocheilus pennocki and Borneo Algae Eater Gyrinocheilus pustulosis unlike Gyrinocheilus aymonieri, they are rarely seen in the aquarium trade.

Note: The word Gyrinocheilus is derived from two separate Greek words, ‘Gyrinos’ which means “Tadpole”, and ‘Cheilos’ which means “Lip” (due to the somewhat triangular, tadpole-like mouth shape).

Natural Habitat of Chinese Algae Eater

Chinese Algae Eater is native to Mainland Southeast Asia. Despite its name (Chinese Algae Eater), it is found in the northern Malay Peninsula, Chao Phraya, Mae Klong, Mekong river basins of Cambodia, Yunnan province in China, Laos, Thailand, and Vietnam. They inhabit waterbodies like lakes, rivers, streams, and flooded fields.

In the wild, Chinese Algae Eater can be found in clear, shallow waters with sufficient sunlight exposure and the presence of dense biofilm which engulfs the substrate.

Substrates usually consist of boulders, gravel, and sand. CAE uses its sucker mouth to attach itself to solid surfaces, especially in fast-moving waters.

They also perform seasonal migration into muddy and deeper waters.

Description of Chinese Algae Eater

Chinese Algae Eater and different color morphs - wild, gold, albino, marble and leucisticChinese Algae Eater is a large fish species with long slender bodies and small fins, the length of its body reaches 11 inches (28cm) in the wild. However, they tend to grow smaller in aquariums where they often rarely exceed 7 – 9 inches (~15 – 22 cm).

Under proper care and good water condition, the Chinese Algae Eater can live up to 10 years.

The species is characterized by the presence of an elongated body, yellow eyes with a black ball, and an interior sucker mouth which they use to anchor to surfaces and scrape algae. A unique feature is the small dorsal fin with several firm rays that gives it a pseudo-spike appearance.

The color of Gyrinocheilus aymonieri varies. They are often yellowish or pale brown, the underside is lighter. Also present are dark black stripe that runs horizontally across the entire length of the fish, sometimes broken into little dots, they lack barbels.

Note: Common Chinese Algae Eaters often become muddy-brown as they get older.

Different color morphs of CAE exist, including gold, albino, marble, and leucistic.

They also possess specialized organs that help water reach their gills when their mouth is affixed on something; two branchial apertures are responsible for this role, they function in a way that forces water across the gills to aid respiration.

Chinese Algae Eaters are quite similar to other shoaling fish species, these include some species of Crossocheilus, for example, Siamese Algae Eater, C. atrillimes, and C. langei, Cambodian logsucker Garra cambodgiensis and Flying fox Epalzeorhynchos kalopterus.

Difference between Chinese Algae Eater and Siamese Algae Eater

Chinese Algae Eater is mostly misidentified as the Siamese Algae Eater. They share some similarities; both are algae eaters and have similar body structure, however, the Siamese Algae Eater has varying body features.

Siamese Algae Eater lacks the distinct sucker mouth of Chinese Algae Eater, and there are jagged edges in its horizontal stripe which extends through the tail fin.

  Chinese Algae Eater Siamese Algae Eater
Body shape More Elongated  
Horizontal Stripe Uneven Smooth
Stripe Stops at the tip of the tail Runs to the tip of the tail
Barbels No Yes
Head shape Eyes are close to the top Eyes are in the middle of the head

Difference between Chinese Algae Eater and Siamese Algae Eater

Chinese Algae Eater Behavior

Chinese Algae Eater is mostly peaceful when they are young, but as soon as they grow older, they become territorial and aggressive towards others. This species is well-known for sucking the slime coats and ripping off the scales off their tankmates, which is a serious problem, as it invites all sorts of infections.

Adult Chinese Algae Eaters are also reputed as feeding off smaller community fish, as well.

Note: CAE are mostly nocturnal and often hide when the other fish are being fed. It can be one of the reasons why they resort to slime sucking and effectively killing all of their tank mates.

They are best kept with active, fast-moving, and top-dwelling fish species; those that spend most of their time in the upper regions of an aquarium.

You should note that adding Chinese Algae Eaters last in an aquarium will help to diminish territorial aggressiveness. Some hobbyists suggest keeping them in groups of 5 to reduce aggression towards other species, but this is only advisable if you maintain a very large tank.

At the same time, small groups (2 – 3) are not advisable as well unless you have a huge tank. The strongest one can bully others to death.

Keep in mind that Chinese Algae Eaters are good jumpers. They are also extremely fast swimmers. It can become a real problem if you decide to catch it in a planted tank.

Chinese Algae Eaters have strong personalities and it can be especially enjoyable watching. They are also pretty shy and skittish.


  • Social: No
  • Active: Yes
  • Temper: Semi-aggressive 

Feeding Chinese Algae Eater

Chinese Algae Eater is a versatile feeder. They will feed on a variety of food apart from algae present in the tank which they are already known to consume.

They should be fed quality flake foods and algae wafers on a regular basis. For example (link to Amazon):

Chinese Algae Eater eats cucumberYou can equally throw in a mix of vegetable matter to substitute algae, blanched vegetables like lettuce, spinach, zucchini or cucumber, and shelled peas can stand in for this purpose.

Important: As youngsters, they do an excellent job of feeding algae, and cleaning plants, rocks, gravel, etc. However, as they mature, their diet radically changes until they barely eat algae at all.

Since Chinese Algae Eaters tend to be omnivorous (more carnivore) as they mature, their diet should be supplemented with meatier food, such as:

Tip: Due to their nocturnal nature, you can feed them about 30-60 minutes after lights out to satisfy their appetite and reduce potential aggression toward tankmates.

Ensure to remove any uneaten food after 24 hours as it can easily ruin the water quality, and this is detrimental to the health of the fish and its tankmates.


  • Diet Type: Omnivore
  • Food Preference: Algae when young, more protein-based food as adults.
  • Feeding Frequency: Daily

You can read more about it in my articles:

How to Blanch Сucumbers and Zucchini for Shrimp, Snails and Fish the Right Way
Indian Almond Leaves and Alder Cones in a Shrimp Tank.

Are Chinese Algae Eaters Plant Safe?

If you have a planted tank, you will always find Chinese Algae Eaters actively searching through the plants and grazing on them. Do not worry, they do not eat healthy plants. However, they will eat dying, rotting, or decaying plants.

Nonetheless, keep in mind that Chinese Algae Eaters are pretty fast and have a strong mouths. It may be a problem for soft and tender plants in the tank, as they can accidentally damage them.

Another problem is that Chinese Algae Eaters often redecorate everything to their liking; they can uproot or knock plants over.

Floating plants, Anubias, Java fern, Amazon Sword can be a good choices for the tank with Chinese Algae Eater.

Keeping and Housing Chinese Algae Eater

What’s good about these fish is their hardiness. They survive well in fast-moving, and also brackish water.

Tank Size:

Pet stores often say that a 10 or 20-gallon (80 liters) tank will be a good choice for this fish. This is wrong. Chinese Algae Eater will easily outgrow these tanks in 4 – 6 months!

The minimum tank size for housing Chinese Algae Eater is 30 gallons (120 L). However, if you plan on stocking a group of these fish then you should opt for a 55-gallon tank (220 L) or more.

Larger tanks are essential because it helps to curb the territorial aggressiveness of adult Chinese Algae Eater and ensure that they maintain adequate spacing from tankmates as they grow bigger. They need some space. It is always the key to territorial aggression and bullying.

Water Parameters:

Temperature: The optimal temperature range for this species is in the range of 74 °F to 80 °F (23 °C to 27 °C).
pH: Chinese Algae Eaters are pretty hardy and can tolerate a pH range between 6.0 – 8.0.
Hardness: Water hardness value should be in the range of 5 – 20 dGH.


You can never go wrong with a fine sand substrate and small gravel mix.

Avoid coarse gravel; its sharp edges can injure/scratch the body of the fish as they swim in the lower regions of the tank.


Light is not important for the Chinese Algae Eater. Lighting should be adapted to the needs of plants in your tank.

Bright lighting will help boost the growth of algae on plants and decors. However, if you are new to this hobby DO NOT do that! You have to understand the balance in the tank. Otherwise, you will have so many different types of algae that will turn into a disaster.

Water flow:

The water movement should be strong enough to replicate the flow in the natural waters that they dwell in. A powerhead or canister filter can provide the much needed current.


The best way to make Chinese Algae Eater feel lively and comfortable is to mimic their natural habitat. You can place large smooth rocks on the substrate, in addition to artificial caves, driftwood, PVC pipes, and twisted roots, these will give them a place to hide or explore.

They are very timid fish. Therefore, it is absolutely important to set the tank up, so they have lots of room to hide and lots of privacy.

Basic Tank Equipment (links to check the price on Amazon)

Care and Maintenance

This fish is easy to care for, you don’t need to have lots of experience to successfully keep Chinese Algae Eater healthy in your aquarium. Ensure that the tank water is always clean and well-oxygenated to provide the fish with the best habitat and living conditions.

You should do a 25% partial water replacement weekly or biweekly, or 25-50% at least once a month to maintain good water quality. This fish is highly sensitive to nitrates, make it a priority to keep the nitrates level as low as you can.

During water changes, use a vacuum siphon to rid the substrate of leftover food and wastes.

Sexing Chinese Algae Eaters

Differentiating between males and females is difficult. However, what you should know is that the females are plumper than the males, although they both have multiple small tubercles or thorns around the mouth, those of the males are more pronounced in spawning conditions.

Breeding Chinese Algae Eaters

There is very little proven knowledge on breeding and reproductive behaviors of Chinese Algae Eater, as well as established methods of successful breeding.

In my research, I have found that in captivity spawning is probably triggered by tweaking of the water temperature and parameters (24°С or 75F, pH 6.8, GH 4 – 5), as seen in many fish species, but that is not certain for now. Good aeration is also an important part.

Next, you will need a group containing male and female counterparts and this is somewhat hard to achieve. Chinese Algae Eaters become mature when they are 1-2 years old.

The Chinese Algae Eater females require some kind of hormonal injections: before spawning and immediately after spawning.

The next day after spawning, the female will lay down around 3000 – 4000 eggs. After that, parents should be immediately removed from the rearing tank. Otherwise, they can eat all eggs.

The incubation period is pretty short, it takes only one day. However, the percentage of healthy eggs is extremely small due to the susceptibility of eggs to fungal diseases. Whitened eggs should be removed at once.

The Chinese Algae Eater fry are not aggressive to each other.

Problems associated with Chinese Algae Eaters

While there are not many diseases specific to Chinese Algae Eater, they may still be plagued by a few common ones.

One of them is Ich. This occurs as a result of a parasite that causes tiny white spots to form across the body. The factor that constitutes to this disease is poor water conditions, therefore, you should always endeavor to maintain stable water parameters to prevent the fish from getting stressed.

Another problem is bloat, which is caused by overfeeding. Feeding fish with a well-balanced diet / right food portion will help to keep them in good shape.

Also, when you detect an unhealthy fish in the tank, you will need to move them into a quarantine tank to prevent the disease from spreading to other inhabitants in the aquarium. When they are back to good health, you can reintroduce them into the main tank.

Chinese Algae Eater and Suitable Tankmates

Chinese Algae Eaters prefer a solitary life, in that regard. Ideally, they should be separated from other fish species especially those of similar size, lifestyle, and appearance with them.

These fish can be a very bad choice for a community tank setup. Think twice before adding Chinese Algae Eater to your tank, you can find much better options such as Pygmy Cory CatfishOtocinclus Catfish, etc.


Large and slow-moving tankmates should not be kept in the same tank with Chinese Algae Eater. This semi-aggressive fish may latch onto their flat bodies in order to eat their slime coat, resulting in injuries and most likely parasitic infections. Some examples are Discus and Angelfish.

Note: Many aquarists believe that this kind of behavior is the result of inappropriate feeding. Chinese Algae Eaters only attack their tank mates when they are really starving.

In some cases, people say that they have never had any problems with Chinese Algae Eater and that they are pretty peaceful. Well, it is either they are very lucky or their fish was only half-grown.

Do not keep Chinese Algae Eaters with small fish species (like Guppies) as well. They can/will eat them.

Possible tankmates to consider are Swordtails, Zebra Danio, Clown loach, Cherry barbs, Tiger Barbs, Emperor Tetra, Platies, and Mollies.

Shrimp and Snails:

Inverts such as dwarf shrimp and freshwater snail should not be introduced into a tank with Chinese Algae Eater as they are very likely to get attacked. This fish can suck the snails out of their shells.

It is possible to keep them with shrimp or snails when they are young and small. Unfortunately, this fish grows very fast, and soon you will need to constantly monitor them to ensure that they are free from possible harm. Until one day it will be too late.

Therefore, no, no, and no.

Dwarf frogs

There are even examples when Chinese Algae Eaters feed on Dwarf frog’s slime skin! Therefore, do not keep them with Dwarf frogs.

Crayfish and Crabs:

Absolutely not! Keep them away from all types of crayfish and most freshwater crabs.

Although it is very unlikely that crustaceans will consider Chinese Algae Eaters as prey. They can still harm them with their claws in the act of defense.

In Conclusion

Even though Chinese Algae Eater is a popular fish for beginner, intermediate and experienced aquarists, this fish may not be the best choice when it comes to peaceful freshwater fish for aquariums. It definitely does its job excellently as an algae eater when it is young, therefore helping to keep the tank algae-free.

However, Chinese Algae Eaters have very specific needs and preferences, or else there can be disastrous results.

They get very large, and in many cases, the pet stores conveniently forget to tell you that. In addition, this fish species is a terror for non-compatible tankmates like Angelfish and Discus amongst others. Unfortunately, lots of people have been tricked into buying the wrong fish!

So endeavor to keep an eye out for aggressive behaviors that are likely to be exhibited by them. Also, keeping Chinese Algae Eater in very large tanks will help to curb their territorial tendencies and ensure that they live in harmony.

Chinese Algae Eater – Detailed Guide Care, Diet, and Breeding pinterest

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