Horseface Loach (Horsehead Loach) Fish Species Profile

The horseface or horsehead loach is a relatively shy bottom-dweller that likes to burrow into the substrate; it will sift the sand through its gills in search of microorganisms or other food. Its long snout is reminiscent of a horse muzzle, hence its name. Peaceful and tolerant of aquarium life, this interesting looking fish is fun to watch as it successfully hides from other fish right near by.

Characteristics

Origin and Distribution

The horsehead loach is found widely throughout Southeast Asia including Borneo, Java, Malaysia, Myanmar, Sumatra, Thailand, and Vietnam. This wide distribution has led some to question if this is indeed a single species, or rather a group of closely related species that have not yet been differentiated. In the wild, Acantopsis species are found in fast-flowing rivers and streams that have mud, sand, or a fine gravel bottom.

First imported to Europe in 1929, this species is now exported extensively. To date, these fish have not been successfully bred in captivity, so all specimens sold in the aquarium trade are wild-caught.

During a revision of loaches by the scientific community in 2012, the scientific name for the horsehead loach was changed from Acantopsis choirorhynchos to Acantopsis dialuzona. However, it is common to find it referred to by either name, as well as by several older synonyms.

Colors and Markings

Elongate in shape, this loach has dark spots sprinkled over a yellowish-brown body color. The color patterns vary somewhat based upon the natural habitat in which the particular fish originated. At the end of the horse-like snout are three pairs of small barbells.

The caudal fin of the horseface loach is slightly forked, and the belly is flat and lighter in color than the rest of the body. Like other members of this family, this species is equipped with a pair of extremely sharp spines under the eye orbits. These spines can be extended as a means of defense when the fish is threatened or attacked. Care should be taken when netting this species, as these spines can easily become entangled in the net.

Tankmates

It is quite common to find this fish nestled under the substrate. They will remain just below the surface of the sand, with only their eyes poking out to allow them to monitor activities nearby. While below the surface, they will sift the fine substrate for small particles of food. Generally, this species is a rather slow swimmer but it is capable of making surprisingly quick darts about the tank when startled. This species is predominantly nocturnal.

Generally a peaceful species, the horseface loach may be combined with other peaceful loaches as well as other peaceful species that occupy the middle and top strata of the tank. These include barbs, danios, rasboras, and tetras. However, this species will do better when it is kept with others of its own kind. Ideally, keep at least a half-dozen of them together, if space allows. Within their own species group, they will often establish their own hierarchy, and may even establish territories that they will defend. To support a school of loaches, always consider a larger aquarium.

Horsehead Loach Habitat and Care

When building a habitat for this species the substrate is particularly important. Because they spend much of their time buried, they must have a fine substrate of either sand or fine gravel. If live plants will be used in the tank, do not plant them with bare roots, as they will be uprooted quickly. Instead, plant them in pots to keep them in place. Sturdy plants such as anubias are ideal. Another option for live plants is to use floating plants, which also subdues the lighting, something that this species prefers.

Driftwood and smooth rocks can also be used in the décor, being placed in such a way as to provide hiding spots. Good water movement is important, as this species requires an oxygen-rich environment. Frequent water changes are also necessary, due to the horseface loach's sensitivity to organic waste. The tank should be mature, as this fish does not cope well with the rapidly changing chemistry of a newly established aquarium.

Horsehead Loach Diet and Feeding

Relatively easy to please, this species will eat most foods that are offered. This fish particularly enjoys live foods and is accustomed to eating small crustaceans and insect larvae in their native habitat. Offering a varied diet will keep them in optimal health.

Since they are bottom feeders, make sure that food is reaching the bottom. This may require providing sinking foods in addition to other types of food. Live or frozen brine shrimp, mosquito larvae, daphnia, tubifex, and bloodworms are all good options for this loach. Lodge live food near the bottom with tongs. Supplemental algae wafers or tablets are welcomed as well.

Because they are more active at night, providing a moonlight is a good way to get an opportunity to observe these fish. Once the primary lighting is switched off, they sometimes will come out in the dim light to actively forage for food. Dropping a bit of sinking food in the tank after the main lights are off will help nudge them to come out of their hiding spots.

Gender Differences

There are very few clear-cut sexual differences between males and females other than size. Adults can reach a length of eight inches, but in most cases, captive specimens remain smaller. Adult females will typically be larger than males, and will also be rounder. 

In males, the first few branched rays of the pectoral fins are extended. However, that subtle difference is not always easy to spot, especially when the fish spends much of its time buried in the substrate. 

Breeding the Horsehead Loach 

There have been no documented instances of this species having spawned in captivity; this includes commercial breeding as well. All specimens sold in the aquarium trade are wild-caught, but their populations in the wild remain robust.

More Pet Fish Species and Further Research

If Horsehead loaches appeal to you, and you are interested in some compatible fish for your aquarium, read up on:

• Weather loach Species Profile
• Tiger barb Species Profile
• Giant danio Species Profile

Check out additional fish species profiles for more information on other freshwater fish.