Crossocheilus siamensis

by Renée/BettaStarz

Known as the "best Algae-Eating fish" in the world. They've earned this title since the Siamese Algae Eater (SAE) are the only known fish that will eat the dreaded Red Beard/Black Brush Algae. But the SAE is quite often confused with so many other members of the Cyprinid family. I'll discuss the differences later

Siamese Algae Eaters will eat Algae all their life. Many of the look-alikes that don't do as good of a job eating Algae as the SAE, and will stop eating it as they reach adulthood. Also, many of the look-alikes when they reach adulthood are very aggressive towards their own kind (look-alikes) or other fish. The SAE is not aggressive towards it's own kind or other fish. That's a very important characteristic difference.

Below is some more information about the Siamese Algae Eater.

Size In captivity they usually only grow to 4 - 5 inches. But they can grow up to 6".
Origin South East Asia (Malaysian Penisula)
Temperature Ranges of 75-82
pH 6.0 - 8.0
Food Omnivorous (with a preference for vegetable-based foods/Algae, Flake Foods, Lettuce and other vegatables).
Tank 30 gallon minimum size (for 2).
Environment Lots of Plants and heavy Filtration. They like clean highly Oxygenated water.
Breeding They do not breed in captivity.
Lifespan Up to 10 years.
Sexing No visible differences. Although the female "may" appear fuller.
Behavior Non-aggressive (although their look-alikes are aggressive).
Activity Very active and are fast Swimmers. They also are prolific Jumpers (you must keep their tanks covered).
Algae Eating Will eat Algae all their life. And is the only known fish to eat the Red Beard/Black Brush Algae (an Aquarium's worst nightmare). Note: Look-alikes do not eat the tough Red Algae, nor do look-alikes eat Algae all their lives like the SAE's do.
Plant Eating They do not eat your Plants. But they may appear like they are, as the eat the Algae off the plant leaves.
Availability Extremely popular and available in Europe. Not as available in North America. Usually one of the look-alikes will be falsely labeled as a SAE. Hopefully, as the become more known for their Algae-eating ability, we'll see many more SAEs here in the U.S. But the fact that they do no breed in captivity is the biggest challenge to their availability.
Other They also like to eat Planaria. Which tend to pop up in Fry Tanks.

Now that you know all about the SAE, it's time to tell you the difference between them and their look-alikes. This way you can spot them more easily. Chances are if you see them labeled 'Siamese Algae Eater' in your local fish store (LFS) they are not true SAE's.

The SAE and it's look-alikes are mistakenly labeled by very creative names, such as: Siamese Flying Fox, Thailand Flying Fox, Thailand Algae Eater, Algae Eater, Algae-Eating Barbs, Siamese Fox, Chinese Fox, and many more misnomers.

Below is a chart and pictures that will help you tell the SAE from it's look-alikes.

Crossocheilus siamensis

Garra taeniata or Epalzeorhynchus sp


  • Barbels (whiskers) - 1 pair
  • Fins - Transparent
  • Black Band - that runs from the nose of the fish all the way through the fork in it's tail (this will rule out all but 1 look-alike, so it should be the first thing you look for)
  • Black Band - edges are in a zig-zag pattern
  • Behavior - Non-Aggressive
  • Activity - Very active fast and smooth swimmer
  • Barbels - None
  • Fins - Has a light colored black band across the Dorsal and Fins are yellowish in coloration
  • Black Band - stops at the Caudal peduncle and does not run through the tail
  • Gold Stripe - Thin Gold Stripe above the Black Band
  • Behavior - Aggressive
  • Activity - Not as active as the SAE, swimming is sort of goofy looking.
Epalzeorhynchus kalopterus
Gyrinocheilus aymonieri
  • Barbels - 2 pairs
  • Fins - Has a dark band across it's Dorsal and Anal fins. Their finnage is very colorful
  • Color - This fish is the most colorful of the look-alikes. And is the one that you'll likely find in your LFS, incorrectly labeled as an SAE.
  • Black Band - runs from the nose through the tail like the SAE.
  • Black Band - is much thicker than the SAE and is very smooth and does not zig-zag
  • Gold Stripe - above Black Band
  • Behavior - Aggressive
  • Activity - Likes to hide
  • Other - The FF looks most like the SAE, however, there are several distinct differences as listed above (most notably the "colored fins" and "2 pairs of Whiskers").
  • Barbels - None
  • Mouth - Has a large "Suckermouth" like a Catfish
  • Fins - Transparent or Spotty
  • Dark Stripe - It looks more like a stripe than a band. And sometimes the stripe looks like spots (see pic)
  • Behavior - Aggressive
  • Activity - Likes to stay at the bottom of the tank and is active
  • Other - The CAE doesn't really resemble the other 3. However, because of it's name it's usually mistaken and sold as a SAE.

The 3 things I look for in identifying the "true" Siamese Algae Eater from it's look-alikes are as follows:

  • Black Band extending through the tail (the Flying Fox band also extends through it's tail, but it's band is much thicker and it does not zig-zag)
  • 1 set of Barbels - (the False Siamensis and the Chinese Algae Eater "do not" have Barbels, the Flying Fox has 2 pairs)
  • Absence of coloration in the Fins (the False Siamensis and the Flying Fox have blackbanding and coloration in their Finnage, the Chinese Algae Eater has no coloration, although they might have spots in their finnage. Again, the CAE doesn't really look too much like the SAE)

Hopefully the above comparisons will help you identify the "true" Siamese Algae Eater. No Aquarium arsenal against Algae is complete without a SAE in the tank!


Frank, N and Sarakontu, L, 1994