Xeruini Tetra

Geographic Origin and Biotope: Rio Negro Basin (Brazil). Inhabits amber water streams (blackwater) and very slow-flowing forest swamps, full of submerged leaves and roots.

Taxonomy and Morphology: Tyttobrycon xeruini. Dwarf characin (barely 2.5 cm / 1 inch). Tiny and partially translucent body. Proportionally large eyes.

Social Behavior: Timid gregariousness. Must be kept in groups of at least 10-15 specimens. Very peaceful but very shy; moves among dense vegetation exploring the leaves.

Coloration and Sexual Dimorphism: Light amber/translucent body with a thin golden and dark lateral line. Males are slightly smaller and more colorful during courtship. Females rounder.

Aquarium Setup: Miniature Amazonian aquarium (Minimum 50 cm / 20 inches). Dark substrate, catappa leaves to release tannins (fundamental) and dim lighting to shield the LEDs.

Diet and Feeding: Micro-predator. Eats only very tiny food: live brine shrimp nauplii, micro-worms (Bananaworms) and high quality powdered dry food.

Water Quality: Extremely demanding. Soft, acidic water (pH below 6.5, better 5.5-6.0) and pristine (zero nitrates). Very sensitive to pollutants and hard water.

Compatibility and Tankmates: Strictly for nano-aquariums. Shares the tank only with small Corydoras (hastatus), Otocinclus or Caridina. Any larger fish will prey on them or stress them to death.

Aquarium Reproduction: Very rare in captivity. Egg scatterers in mosses. Parents must be removed after spawning, but the larvae are so tiny they require infusoria.

Risks and Diseases: Osmotic shock and food competition. They suffer atrociously in tap water (hard) and starve if kept with voracious fish that steal their food.