Care Guide for Siamese Algae Eaters (SAE) — Housing, Food, and More

If you visit our retail store or warehouse, you’ll notice that many of our plant tanks employ the services of the Siamese algae eater (SAE). This hungry animal is always looking for food, which makes it one of the best algae eaters and cleaner fish in the fishkeeping hobby. However, its 6-inch (15 cm) adult size means the SAE more suitable for medium to large aquariums. Learn what it takes to care for this very energetic and effective algae eater.

What are Siamese Algae Eaters (SAE)?

Crossocheilus oblongus (formerly C. siamensis) hails from Southeast Asia and looks like a miniature freshwater shark because of its torpedo-shaped profile and sharp snout. Both sexes have very similar appearances, except the female may have a chunkier body because of her ability to produce eggs. Besides its algae-eating abilities, the SAE's eye-catching appearance and active swimming behavior makes it a fish store favorite, and this species reportedly has a longer lifespan compared to other smaller fish.

What is the difference between the Siamese algae eater, Chinese algae, eater, and flying fox?

• The Siamese algae eater grows to 6 inches (15 cm) long and has a bold, black line down its side with a tannish-gray back and lighter-colored belly. It has a pointy face and shark-like body, and its fins and tail are completely clear.
• The Chinese algae eater can reach 11 inches (28 cm) in length and has a large suckermouth (instead a pointed mouth like the SAE). The regular version is brown in color with a bumpy black stripe down the middle, whereas the gold variety is entirely golden-yellow without any black stripe.
• The flying fox is much more similar to the SAE in appearance because of its 6-inch (15 cm), shark-like profile. However, it has a thin, shiny gold line that looks like it’s surrounded by two black stripes. Also, the fins are not clear but instead have black markings on them.

Left to right: Siamese algae eater (Crossocheilus oblongus), Chinese algae eater (Gyrinocheilus aymonieri), and flying fox (Epalzeorhynchos kalopterus)

How to Set Up an Aquarium for SAE

A single SAE can live in a 50- to 55-gallon freshwater aquarium with a tight-fitting lid to prevent it from jumping out. They are quite hardy when it comes to water parameters and can be kept in temperatures between 68–80°F (20–27°C), pH of 6.0–8.0, and soft to hard water. In the wild, they are found in clear streams with lots of algae and biofilm growth on the rocks and driftwood, so provide them with hardscape and other decor to graze and rest on. SAEs are safe with aquatic plants, but some hobbyists report that they may nibble on the leaves if they are not fed enough.

How many Siamese algae eaters should you keep together? Technically, the SAE is a shoaling fish that swims together in large groups, but in an aquarium setting, they can be semi-aggressive towards their own kind, especially as they get older and start establishing a pecking order amongst themselves. We personally find that a single Siamese algae eater can do quite well by itself, but if you plan on buying a group of them, make sure you get at least three or more to spread out the aggression. Increasing the tank volume for each additional SAE and providing obstacles that block line of sight will also minimize any territorial infighting.

What fish can live with Siamese algae eaters? They can get along with other tank mates in a community setting, as long as you take their speed and bottomless stomachs into account. To make sure they don’t hog all the available food, pair them with similar-sized, fast-swimming species — such as loaches, barbs, giant danios, cichlids, and livebearers. They will eat dwarf shrimp but seem to leave most snails and larger shrimp alone.

SAEs do well in planted community tanks when paired with the right tank mates.

What Do Siamese Algae Eaters Eat?

This omnivorous species is not picky and will happily consume both protein and plant matter — including flakes, wafers, freeze-dried foods, frozen fish food, and blanched vegetables. Its downturned, small mouth allows it to reach every nook and cranny when searching for small food particles, freshwater plankton, and of course algae that grows on surfaces. Because juveniles require a lot of nutrients to grow, they will forage nonstop for leftovers and all kinds of algae — including hair and black beard algae (BBA). As they reach adulthood, their hefty size allows them to get the lion’s share of the fish food, so they are less likely to graze on algae. To get older SAEs to eat algae again, try cutting back their meal portions or even fast them for a week to whet their appetites.

Siamese algae eaters prefer to eat fish food over algae when given the option.

While Aquarium Co-Op does not ship live fish, you can check out our list of preferred online retailers to see what fish, shrimp, and other aquatic animals they have in stock. Also, if the Siamese algae eater is too big for your tank, read our online article on the 10 Best Algae Eaters for Freshwater Aquariums.