Madagascar Rainbowfish

Geographic Origin and Biotope: Endemic to eastern Madagascar (Mananjary river). Inhabits mountain streams shaded by forests, characterized by clear, highly oxygenated waters with a moderate current, flowing over pebble and sand bottoms.

Taxonomy and Morphology: Madagascar Rainbowfish (Bedotia geayi / ex B. madagascariensis). An atypical Rainbowfish. The body is tapered and cylindrical (not high and compressed like Australian Melanotaenia), with a conspicuous second dorsal fin shifted towards the tail.

Social Behavior: Extremely peaceful but hyperactive. It is an obligate "schooling fish": it must live in groups of at least 6-8 specimens. The school is compact and tirelessly patrols the middle and upper levels of the aquarium in an endless swim.

Coloration and Sexual Dimorphism: Pale gray-golden body crossed by a thick horizontal black band. The magic is in the fins: dominant males sport fiery red or bright orange margins on the dorsal and caudal fins (which often end with intense red spots). Females have transparent fins.

Aquarium Setup: Requires very long aquariums (min. 100 cm / 40 inches). Needs a vast open space for swimming in the center and on the surface. On the sides, groves of plants and blunt river rocks with a moderate pump flow to simulate the stream.

Diet and Feeding: Omnivore (Micro-predator). In nature it consumes insects fallen on the surface. In the tank it accepts protein flakes, floating or freeze-dried bloodworms, and minute krill. It struggles to feed from the bottom due to the terminal-superior mouth.

Water Quality: Tolerates well medium-hard tap water (GH 8-15) and neutral to slightly alkaline pH. Excellent water quality and very strong oxygenation are fundamental (appreciates a thermal drop of 2°C / 4°F during the night).

Compatibility and Tankmates: The perfect companion for endemic Madagascar Cichlids or for lively communities with Danios, large peaceful Barbs and Loricariids. It does not nip, but its frantic back-and-forth will exhaust slow or shy fish (e.g. Angelfish and Gouramis).

Aquarium Reproduction: Relatively simple (Plant egg-scatterer). They lay large eggs daily equipped with adhesive filaments that hook onto mosses or acrylic wool mops. If well fed, parents do not prey on the eggs or young.

Risks and Diseases: Imminent extinction in nature due to deforestation in Madagascar; it is kept alive only by the aquarium hobby. Very sensitive to impact injuries: tanks that are too short cause them to crash into the side glass.