Boeseman's Rainbowfish

Geographic Origin and Biotope: Endemic to the Ayamaru Lakes (Papua, Indonesia). These karst lakes have crystal clear, alkaline waters rich in submerged aquatic plants.

Taxonomy and Morphology: Boeseman's Rainbowfish (Melanotaenia boesemani). The rainbowfish par excellence. The adult male has a high, massive and flattened body, with the two dorsal fins very close together.

Social Behavior: Gregarious, peaceful, tireless swimmer. Males exhibit their love parades (Flashing) lighting up with fluorescent colors to impress females at dawn, crossing each other at full speed.

Coloration and Sexual Dimorphism: Unmistakable "half-and-half" dichromatism: the head and the front part of the body are a metallic Blue-Violet, while the rear half (caudal peduncle included) is bright Yellow-Orange. Females remain more slender, silver and less brightly colored.

Aquarium Setup: Long tank (120 cm / 48 inches min) to allow school swimming. Leave the center completely clear for the parades. Stem plants and intricate roots should be confined to the back. Likes intense light and dark background to maximize colors.

Diet and Feeding: Water column omnivore. Needs natural carotene (Astaxanthin, Krill, Spirulina) to develop the orange half of the body. Insert frozen bloodworms and shrimp-based pastes.

Water Quality: Attention to the lakes of origin: the Ayamaru lakes are karst, therefore the water MUST be hard (GH > 10) and alkaline (Ph > 7.5). In soft and acidic water (like Amazonian), boesemani will waste away.

Compatibility and Tankmates: Ideal fish for robust community tanks. Insert together with rainbowfish of the genus Glossolepis (G. incisus), Clown Loaches and Barbs. Due to their hyperactivity, do not associate them with Discus or excessively shy/slow fish.

Aquarium Reproduction: Mop Spawner. Breeders drop a few eggs daily tangled in the vegetation with sticky filaments (they do not eat their offspring if well fed). The eggs take about 7-10 days to hatch.

Risks and Diseases: Juvenile disappointment. Very often sold at the juvenile or sub-adult stage, they appear as very sad "little gray fish". Many snub them; in reality they will take up to a year of excellent care to develop the glorious blue/orange colors.