Common Names: Kuhli loach, kuhlii loach, coolie loach
Type Locality: Jakarta, Java, Indonesia
Taxonomic Troubles: Originally Cobitis kuhlii. Until recently known as Acanthophthalmus kuhlii. Various species of Pangio are imported as kuhlii loaches, all are similar in requirements and care.
Size: 12 cm (4.7 inches)
Preferred Water Chemistry: Tropical, soft, acid; pH 5.5 to 6.5, under 100 ppm, 24 to 30 degrees Celsius (75 to 86 degrees Fahrenheit)
Difficulty: Fairly hardy, if their special needs are met
Tank Setup: These are strictly bottom fish. They need dense cover, preferably deep, dark caves. They will congregate in large numbers in cavitites under rocks or driftwood, or in a peat moss substrate.
Feeding: These fish can easily starve to death in a typical community aquarium. They are meek, shy, nocturnal bottom feeders, and provision must be made for getting sinking foods to them. They leave their hiding places after dark and do a complete job of scaveng
Breeding: Occasionally spawned. Conditioned females become unmistakably gravid with swollen bellies tinted green. A pair typically swims up to deposit the green eggs in floating vegetation. Young can take baby brine shrimp and are reported to have external gills at first.
An elongate, worm-like shape, with a tan base coloration overlaid with many irregular dark bars. All fins are greatly reduced in size, and the fish rarely swim, preferring to move purposively along the bottom.
Always popular due to their unusual shape and bottom-hugging crawl, these fish do not typically receive proper care. They cannot compete with other fish for food or hiding spots. The best setup for them is one in which they will rarely be seen; they will learn to slither out of their caves when food is dropped into the tank, but they will always lose out to faster, more aggressive tankmates. It is, however, a comical sight to see a bunch of them crawl out and begin combing each grain of gravel for tasty morsels. They seem to propel themselves forward by nosing over the substrate.
The more the merrier is definitely the case with this species. In fact, a species tank with a dozen or more of these fish is an ideal setup. Obviously, their worm-like appearance makes them irresistible to any fish with a mouth large enough to ingest them, so between getting eaten and losing out on the chow line, kuhlii loaches do not fare well with most tankmates. The most notable exception is with mild-mannered surface dwellers like gasteropelecid hatchetfish. Filtration for these sedentary, skinny fish need not be very robust, and water currents should be kept minimal with such setups as spray-bar returns. In fact, these fish were first spawned in the early days of the hobby in unfiltered, heavily planted tanks, in which they were kept without other fish and fed live foods generously.