Checkerboard Cichlid

Geographic Origin and Biotope: Rio Negro basin (Brazil and Venezuela) and Orinoco. Dominates tea-colored blackwaters, very dark and tannic, in shaded streams full of leaf litter and white sand, almost devoid of aquatic plants.

Taxonomy and Morphology: Checkerboard Cichlid (Dicrossus filamentosus). Very peculiar dwarf Cichlid. It does not have the stocky size of Apistogramma: its body is elongated and tubular, resembling a pencilfish (Nannostomus).

Social Behavior: Peaceful, calm but strongly gregarious-hierarchical. Moves by slowly patrolling the bottom in schools, unlike typical dwarf Cichlids. A male can manage a harem of many scattered females.

Coloration and Sexual Dimorphism: Unmistakable "checkerboard" pattern (2-3 rows of black squares on a silver/beige background). Dominant males possess a spectacular fringed caudal fin (filaments) with red-blue colors. Small, round females with red ventral fins during brooding.

Aquarium Setup: Strict Blackwater biotope: low and wide tank (at least 80-100 cm / 32-40 inches). Very fine inert sand entirely covered by catappa, oak or beech leaves. Tangled roots, soft light, NO calcareous rocks.

Diet and Feeding: Omnivore specialized in sifting sand and leaves. Offer live brine shrimp nauplii, cyclops, daphnia and microworms. Eats industrial granules with great difficulty (which must sink fast and not swell).

Water Quality: Limit chemical ecosystem for a hobbyist aquarium. Demands temperatures of 28°C (82°F) or more, a distinctly acidic pH (4.5 - 5.5 in reproduction) and virtually distilled water rich in peat.

Compatibility and Tankmates: The ideal is a species-only tank. Excellent surface companions: Hatchetfish (Carnegiella), Cardinals (Paracheirodon) and Nannostomus. Avoid Apistogrammas, active Corydoras or invasive Loricariids.

Aquarium Reproduction: Extremely difficult. Lays red eggs on broad sunken leaves, rather than in hidden dens! The female becomes very red and furious, protecting the litter from everyone, including the male. The larvae tolerate only very soft water (TDS < 30).

Risks and Diseases: Deadly sensitivity to nitrates and bacterial pollution of the bottom. If the water values are wrong (e.g. pH 7, high GH), it wastes rapidly and is a fixed prey of dropsy.