Porthole Catfish

Geographic Origin and Biotope: Endemically widespread throughout the large Amazon basin (Peru and Brazil). Tireless populator of swamps, slow-flowing igarapés, and stagnant alluvial tracts. Exploits the very dense underwater foliage to camouflage perfectly among shadows, roots, and silt.

Taxonomy and Morphology: Known as the "Porthole Catfish". A 10-centimeter (4-inch) siluriform exponent of the Callichthyidae family. Cigar-shaped and tapered body used for horizontal swimming in mid-water, shielded along the flanks. Possesses two sets of unusually elongated barbels (longibarbis).

Social Behavior: Hyperactive but very timid fish and prone to acute psychosis in captivity if kept solitary or exposed to open and bare tanks. Obligatory and categorical stationing in thick schools of at least 6-8 individuals, where the species will lose its inhibitions, floating in a group among the branches.

Coloration and Sexual Dimorphism: Extreme sobriety: "dirty" pinkish-sand livery decorated laterally by a decisive longitudinal row of circular black spots (similar to portholes, hence the name). Dominant males flaunt notably swollen first pectoral spines, encrusted with tiny sensory villi (hairs).

Aquarium Setup: Pelagic and benthic swimmer: combine free swimming with intricate Vallisneria forests, huge broad-leaved plants and floating bark to alleviate panic. The substrate must be, here too, necessarily of very fine rounded sand. Tanks with generous volumes (> 150 liters).

Diet and Feeding: Micro-predator. Sifts water and soil hunting frantically both day and night. Excellent devourer of bottom fish tablets, willingly accepts semi-floating granules mixed with conspicuous administrations of tubifex, bloodworms and large daphnia or mysis.

Water Quality: Temperate/warm, loves Amazonian temperatures of 24-28°C (75-82°F). Tolerant on average ranges: neutral-subacidic pH (6.0 - 7.2) and moderate GH (2-15). Endowed with strong resistance, takes in atmospheric air swallowing it (accessory intestinal respiration) in case of warm waters poor in oxygen.

Compatibility and Tankmates: Sweetest tankmate for Amazonian biotopes with calm waters. Triumphant insertion together with imposing schools of medium-sized Tetras (Lemon tetra, Bleeding heart) and quiet Cichlids (Mesonauta, Cleithracara, Geophagus). Exclude fierce Astronotus or hostile loricariids.

Aquarium Reproduction: They do not lay like Corydoras. The male engineers and builds a large and compact nest of bubbles and vegetation anchored on the surface to large leaves or floating plants, in which he crams the eggs following mating and which he will rabidly defend against intrusions.

Risks and Diseases: Many specimens succumb in the first days in the tank due to sudden jerks caused by panic (crashing against the glass) in overly bright and bare tanks. Enormous sensitivity to intoxication with intensive treatments based on Malachite Green.