Chili Rasbora

Geographic Origin and Biotope: Endemic to the Jelai river basin in Central Kalimantan (Borneo, Indonesia). The natural habitat consists of peat swamps covered by the forest canopy, in which the water ("blackwater") appears the color of dark tea.

Taxonomy and Morphology: Chili Rasbora / Mosquito Rasbora (Boraras brigittae). One of the smallest aquarium fish in the world (often not exceeding 1.5-2 cm / 0.6-0.8 inches). Slender and tapered shape. Not to be confused with the similar B. urophthalmoides (less red).

Social Behavior: Obligate schooling fish of a very shy nature. Must be kept in large groups (minimum 10-15 specimens, better dozens) to dispel fear. Without a group, it will die of stress hiding forever.

Coloration and Sexual Dimorphism: Adult males have a spectacular fiery red/chili livery that contrasts with a long and bold irregular black band running along the lateral line. Females are slightly more faded (pinkish-orange) and have a noticeably more swollen abdomen.

Aquarium Setup: Perfect for nano-aquariums (from 20-30 liters / 5-8 gallons for a small group). Requires very dense planting, low lighting, floating plants and dark water enriched by woods and leaves. The filter must have a very gentle flow.

Diet and Feeding: Micro-predator. Because of its tiny mouth it needs powdered foods, pulverized microgranules, infusoria and newly hatched brine shrimp nauplii. They really appreciate live microworms.

Water Quality: The brightest colors are revealed in soft and weakly acidic water, but captive-bred generations tolerate values close to neutrality well. Extremely sensitive to ammonia and nitrite peaks.

Compatibility and Tankmates: Ideal in a Species Tank or with shrimp (Neocaridina spp.) of which they prey only on newly hatched young. Shareable only with dwarf Corydoras (pygmaeus), Pangio or Otocinclus. Never with carnivorous or medium/large fish.

Aquarium Reproduction: Continuous egg scatterers among mosses and dense foliage. No parental care. In a well-established and mature tank (rich in biofilm and microorganisms) some fry may survive and join the school spontaneously.

Risks and Diseases: They constantly risk being sucked into the filter intake grille. Use of a sponge pre-filter or air filters is mandatory. Malnutrition from "food too big" is a frequent cause of death.