Scarlet Badis

Geographic Origin and Biotope: Northeast India (Brahmaputra basin, West Bengal). Inhabits slow ditches, calm pools and clear shallow waters saturated with patches of extremely dense vegetation.

Taxonomy and Morphology: Scarlet Badis (Dario dario). One of the smallest freshwater vertebrates in the world (often under 2 cm / 0.8 inches). Belongs to the Badidae. Sedentary character and "jerky" movement like a hummingbird.

Social Behavior: Micro-fish with the temperament of a dwarf Cichlid. Males establish very small defined territories and fiercely defend them in spectacular displays towards each other. Only one male per tank (with females) is recommended unless you have over 60 cm (24 inches) of space.

Coloration and Sexual Dimorphism: The male is an absolute jewel: seven vibrant red vertical bands alternating with silver-blue bands. The fins are bright red edged in ice white. Females are tiny, stocky, and almost entirely gray, lacking red pigment (impossible to find in shops).

Aquarium Setup: The king of nano-aquariums (20-30 liters / 5-8 gallons are sufficient for a pair). Absence of vigorous current. Plant every square inch: rocks encrusted with moss, ferns (Microsorum), carpets and Cryptocoryne. Lots of shelters are vital.

Diet and Feeding: Critical point: it is a micro-predator that will almost always ignore dry feeds. Feed daily with tiny LIVE prey (Daphnia, Microworms, Grindal, brine shrimp nauplii). With dedication it accepts frozen foods (bloodworms) waved in front of its nose.

Water Quality: Prefers cool subtropical temperatures (18-23°C / 64-73°F). Tanks heated to 27-28°C (81-82°F) drastically shorten its life. Very clean water and very slow sponge filters so as not to affect oxygenation.

Compatibility and Tankmates: To be kept strictly alone or with very few equally shy nano tankmates (e.g. Boraras brigittae). Adult Caridina shrimp are safe, but it will systematically eat the "zoeae" (baby shrimp).

Aquarium Reproduction: A receptive female enters the male's bush (territory). After the embrace, she lays a single adhesive egg which the male will defend. Microscopic fry demand Infusoria or live paramecia.

Risks and Diseases: Extreme thinness and deadly wasting due to food competition with tankmates. Fake females (submissive males who lose their colors so as not to be killed) complicate reproduction.