Both the common names for this species are misnomers, since this fish is not a “true” loach—as in the barbel-bearing Balitoridae and Cobitidae — and it does not occur in China. It does, however, eat algae and is able to attach itself to the substratum with its suckerlike mouth. It also has special adaptations, such as an aperture in the top corner of the gill cover that allows it to take in water for respiratory purposes while still clinging onto a surface with its mouth. A golden form of this species is now widely available.
This is a variably patterned species, giving rise to speculation that the fish currently considered P. myersi may consist of more than just a single species, or may contain several subspecies. Similar doubts surround some of the other species in the genus, making a detailed review highly desirable. In addition to Myer’s Loach, the following are the main species currently encountered in the hobby. All have similar behavioral characteristics and aquarium requirements: P. semicinctus (Half-banded Kuhli Loach) from the Malay Peninsula; P. kuhlii (“True” Kuhli Loach) from Java, Sumatra, Malaysia, Singapore, and Thailand; P. javanicus Gavanese Loach) from Java, and P. shelfordi (Shelford’s Loach) from Malaysia and Borneo.
The Kuhli Loach can be divided into two distinct subspecies on the basis of its coloration and markings: Pangio kuhlii kuhlii and P. kuhlii sumatranus (Sumatra Kuhli). The latter subspecies usually has fewer than 1 5 black circular bands along the length of its body, while P. kuhlii kuhlii has narrower, redder bands, and the black areas do not totally encircle the body. Kuhli Loaches have defensive spines close to the eyes. If threatened, they can raise the spines, which will easily become stuck in a net or in the mouth of a would-be predator.
Weather loaches, such as the Dojo, are renowned for their sensitivity to barometric pressure. When it drops—as happens preceding a storm — the drop in gas pressure in the swimbladder makes these fish very active. Thus they are said to be able to “predict” stormy weather. If the pressure drop is excessive, weather loaches (both the Dojo and its European relative, M.fossilis, the Pond Loach) will “burp” or “break wind.” Golden forms of the Dojo and of M.fossilis are also available.
This small spotted species is often found in quiet, slow-flowing waters with a sandy bottom into which it sometimes burrows. It feeds mainly on detritus and algae. The Lesser Loach was originally found in an area of thermal springs, hence its scientific species name “thermalis”.
There are several forms of this loach (regarded as subspecies by some authors). It is quite sensitive to high temperatures and is therefore strictly a species for the coldwater aquarium. In its natural habitat the species is known to be an important source of food for trout.
The peaceful nature of this species, together with its habit of destroying unwanted snails and other water pests, makes it an excellent choice for a community aquarium. Compared with other Botia species, it remains fairly small. Because of its patterning, it is sometimes confused with B. helodes (Banded Loach).
This small gem—as its common name suggests, it is the smallest member of the genus Botia—is now available more widely than it was during the latter decades of the 20th century. For optimum effect, it is best to maintain a shoal of a minimum of six specimens.
This is an unusually, but most attractively, colored species. It is sometimes confused with B. lecontei (Leconte’s Loach). However, in Orange-finned Loach all the fins are orange to yellow, while in B. lecontei the dorsal fin is grayish blue.
This is the best known and probably the most attractive of the Botia loaches. Owing to its relatively large size, it is considered a food fish in its native waters. Like its relative, B. helodes (Banded Loach), it is known for making clicking noises when excited.