The Sucking Loach

The Sucking Loach (Gyrinocheilus aymonieri)

Order Cypriniformes, Family Gyrinocheilidae

Common names Sucking loach, Indian algae eater, Chinese algae eater, Siamese algae eater, Golden algae eater, Asiatic Scale Sucker

Synonyms Psilorhynchus aymonieri, Gyrinocheilus kaznakovi, Gyrinocheilus monchadskii

Description
The Sucking loach is a large fish, growing up to eleven inches. Although it is unlikely to reach its full size in the aquarium, it will nonetheless grow to be a large fish, usually around six inches. The natural colouring is in shades of brown – a brown back with a darker irregular horizontal stripe along the side which does not extend into the tail. The stripe may even be broken up sufficiently to form a row of spots in some specimens the stomach is pale grey. Although in its natural form this is not a particularly attractive fish, albino and part-albino aquarium variations are often available ranging from bright orange with a red eye to a mixture of brown and orange colouring. Mature male albinos show a pattern of regular red spots on the nose – this is not a disease, but tubercles. A variety of other fishes are often sold under the same name, especially the true Siamese Algae eater, Crossocheilus siamensis. Crossocheilus can be identified by the regular, smooth-edged horizontal stripe, which extends into the tail fin, and is a peaceful fish which is not to be tarred with the same brush. The sucking loach has no barbels, unlike true loaches.


Behaviour
Siamese algae eaters crowd together when small in the aquarium shop, but as they grow become increasingly aggressive and territorial. A foot long territorial fish requires a great deal of space to house it. The mouth is located on the underside of the head, and is designed for attaching to food and rasping at it; openings on the gill cover allow the fish to breathe while still firmly hanging on with its mouth. While small the fish can often be seen grazing across the aquarium glass, but as they grow they consume less and less algae. Even when young, the algae does not appear to be reduced dramatically, and it has been suggested that what they are actually doing is feeding on microorganisms living in the algae.

Aquarium requirements
These are tough and hardy fish, which will adapt to a wide range of water conditions. As aggressive fish, they are not suited to a community and should be kept alone. Wide bodied tankmates are particularly vulnerable to attack, and these loaches can attach to the sides of their companions and feed, initially on the mucous, but soon on the flesh of their unfortunate companions. An outbreak of ulcers and open wounds in a tank which contains a sucking loach does not take long to find the cause.

Feeding
Although the fish are often described as vegetarian in literature, if there is a choice between meaty foods and vegetable ones they usually choose a meat diet, and become almost completely carnivorous as they mature. They will, however, eat flake foods or pellets happily and voraciously.

Breeding
There is no information on the breeding of the sucking loach. Although the adult fish often develop tubercles on the nose, which is usually an indication of being ready to spawn, these fish are reputed to have been spawned only recently.

Diseases and disorders
The sucking loach is a tough and robust fish, more likely to cause problems in the aquarium than to suffer from them.

Notes
The sucking loach appears in this series of articles for two reasons; firstly it is indeed a beginner’s fish, being almost impervious to harm, but secondly because it is almost universally sold with misinformation. Nearly every aquatic outlet and publication propagates the idea that this fish is an ideal hard-working inhabitant for a community aquarium, when it is exactly the opposite. For someone who would like to try something different, a species tank for sucking loaches offers the opportunity to try a species about which little is known. For an aquarist who would like a community aquarium, this fish will be a disaster.

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