Boraras maculatus(DUNCKER, 1904)
Type Locality: Bukit Terah, Bandar Maharani, Johore, Malaysia
Range: Malay Peninsula to Sumatra, Indonesia
Taxonomic Troubles: Originally described as Rasbora maculata, moved to the new genus as part of the 1993 revision of this group. At times these fish were considered to be juvenile Rasbora kalochroma.
Size: 2.5 cm TL (1 inch), one of the smallest vertebrates
Preferred Water Chemistry: Tropical, found in forest streams in soft, acidic water, but is quite adaptable, at least outside of spawning.
Difficulty: This is a hardy fish. The only concern is its small size as it affects tankmate choice and providing sufficient tiny foods.
Tank Setup: A small, heavily planted tank is ideal, and a dark substrate shows them off the best; these fish must be kept in schools, preferably 10 or more. Tankmates must be small to avoid predation, and highly energectic species like danios may intimidate these shy
Feeding: A micropredator that will usually take suitably sized prepared foods but greatly prefers small live or frozen invertebrates.
Breeding: This species has been bred in home aquaria. The fry, of course, are quite tiny and require the smallest of live foods at first—green water is a good choice. Males are more colorful and slender.
Description: One of several tiny, bright red rasboras; it has variable dark markings—a black leading edge to the dorsal and ventral fins, a large black mid-body splotch, and black spots or splotches at the ventral fin insertion and the caudal peduncle. Both the red coloring and dark spots vary considerably.
Notes: This is an ideal fish for a nano aquarium setup. While each individual is beautiful, the cumulative efffect of a large group adds to this display. A nice school can be kept in a desktop aquarium with some Java moss, whose deep green will contrast nicely with the scarlet fish; this plant also thrives under subdued lighting that these fish prefer. In a larger tank with peaceful tankmates they will school tightly, but if kept on their own in a small system, the individual fish will be much bolder and spread out in smaller groups through the plantings. When conditions suit them, their colors will be boldest—they will probably be quite washed out when you first bring them home until they get settled in. Fish with red pigments typically derive their color from their diet, so be sure to include foods high in caretenoids, like shrimp. Freeze-dried cyclops are an excellent choice and are very well accepted by the fish. Several very similar species are also imported, so making a positive identification may be difficult, but this is not a problem, since care is the same for all of them. People who have bred these rasboras successfully have used fairly soft and acidic water, but these fish do well in just about any aquarium water.