Dwarf rasbora

Geographic Origin and Biotope: Widely distributed in Southeast Asia (Peninsular Thailand, East Malaysia, Singapore, Sumatra). Inhabits peat swamps (blackwater) and river inlets closely associated with the ancient pristine rainforest.

Taxonomy and Morphology: Dwarf Rasbora (Boraras maculatus). "Maculatus" refers to the three characteristic dark spots on the body. Slightly plumper and larger (2.5 cm / 1 inch) than the very slender B. brigittae.

Social Behavior: Obligatory schooling fish. Creates cohesive groups (recommended from 15 specimens up) that swim elegantly in shaded areas. Totally harmless nature towards everything and everyone.

Coloration and Sexual Dimorphism: The body is tinted pinkish-red or soft orange. It has a prominent round spot behind the gill covers, one at the base of the anal fin and one at the base of the tail. Dominant males are distinctly redder and more slender than gravid females.

Aquarium Setup: A 40 cm (16 inches) tank hosts a good school. Lighting should be shielded by a thick blanket of floating plants (e.g. Pistia, Salvinia). Greatly appreciates tannins released by alder cones and Indian almond leaves (Catappa).

Diet and Feeding: In nature it preys on zooplankton and microscopic worms. In captivity it accepts very fine crumbled flakes, but the staple food must be brine shrimp nauplii, copepods, daphnia and microworms.

Water Quality: It poorly tolerates hard and alkaline tap waters, which fade its colors and reduce life expectancy. Needs parameters tending to acidic (pH 5.0 - 6.5) and extreme cleanliness without having currents in the tank.

Compatibility and Tankmates: See Boraras brigittae: safe cohabitation only with Neocaridina, peaceful snails, Pangio and Corydoras pygmaeus/hastatus. In a community aquarium with fish over 4 cm (1.5 inches) it would quickly be consumed or die of stress.

Aquarium Reproduction: Scatters sticky eggs daily on tufts of Java moss or Riccia fluitans. If the school is well fed and the mosses are thick, it is possible to see slight increases in population without any intervention by the aquarist.

Risks and Diseases: Many wild populations (e.g. in Singapore) are now extinct due to the conversion of peatlands into cultivated land. Very sensitive to sudden changes in pH and, due to its size, a victim of filters without a protective sponge.