The Saddleback Hillstream Loach (Homaloptera orthogoniata) is a very rare and beautiful species that is native to both Malaysian and Indonesian Borneo. It is known for its multi-colored brown, tan, and red coloration. This fascinating, peaceful fish is primarily an algae and biofilm grazer that is an excellent candidate for the mature subtropical an tropical aquarium.
An aquarium with heavy water flow (10-15x turnover per hour) and very clean, clear water is required for the Saddleback Hillstream Loach. Like other hillstream loaches, this loach is native to shallow, clear, fast-flowing waters and it is sensitive to declines in water quality, so regular aquarium maintenance and maximum oxygen saturation are absolutely necessary.
The Saddleback Hillstream Loach is primarily a biofilm and algae grazer in nature, but it also feeds on very small crustaceans and other invertebrates. It is known to often accept frozen meaty foods, but such foods should only be part of its diet. This fish will also often accept high-quality dry foods that are rich in plant matter, but it is absolutely essential that biofilm and algae are naturally available in the aquarium to ensure its long-term health or else it may slowly starve or suffer from incomplete nutrition. As long as it is kept in a well-maintained, mature aquarium with good biofilm and algae growth as well as high water flow, the Saddleback Hillstream Loach is a hardy and entertaining fish. It will not bother aquarium plants. In fact, Anubias species are an excellent plant to keep with this loach because Anubias can foster significant biofilm/algae growth in an aquarium with moderate to high lighting.
The Saddleback Hillstream Loach is a very social species, especially as an adult, so it should be kept in groups. Most small rasboras, tetras, hillstream loaches, gobies, and other small, peaceful fish are good tankmates for this species. Since they inhabit similar waterways, many smaller freshwater goby species are ideal tankmates as well. It can be kept with invertebrates too large to be considered prey, but dwarf shrimp might fall under the category of "potential prey items" due to the size of the Saddleback Hillstream Loach. Peaceful bottom-dwelling fish are also a possibility, but care must be taken to make sure that the Saddleback Hillstream Loach is not outcompeted for food.
Little reliable information is known about the breeding habits of the Saddleback Hillstream Loach. However, it is not necessarily unlikely that it will soon be bred in the aquarium world, especially with the recent progress in breeding other loach species by many individuals.