Pseudotothyris obtusa

Pseudotothyris obtusa is a member of the otothyrine loricariid group, a clade within Loricariidae that includes Otocinclus and its close allies. Described from Atlantic Forest coastal rivers of southeastern Brazil, it is a small, compact catfish with a rounded snout (reflected in the name 'obtusa') and subtle reticulated or mottled dorsal patterning that provides camouflage against sandy and gravelly stream substrates.

In its natural Atlantic Forest habitat, P. obtusa inhabits clear, moderately cool to warm coastal streams with sandy and gravelly substrates, occasional boulders, and abundant driftwood and leaf litter. It grazes biofilm from wood surfaces and leaf litter as much as from hard rocky substrate — a dietary breadth that makes it less dependent on algae production than some of its relatives. This adaptability to organic-rich biotopes may ease its transition to life in the aquarium.

For aquarists, P. obtusa is a gentle and understated species suited to Atlantic Forest biotope setups or careful soft-water planted aquaria. Its affinity for driftwood and leaf litter means it integrates naturally into blackwater-influenced setups. It is best kept in groups and maintained with excellent water quality, moderate temperature, and reliable supplemental feeding.

Water: Soft to moderately hard at pH 6.0–7.5 and 18–24°C; leaf litter and driftwood provide tannins that replicate Atlantic Forest stream conditions. Tank: 40 litres minimum with driftwood, Indian almond leaves, and fine substrate. Feeding: Biofilm on wood and leaf litter primary; supplement with algae wafers and blanched vegetables. Breeding: Not documented; driftwood-rich, slightly acidic setup is the probable prerequisite. Compatibility: Peaceful with all small Atlantic Forest community species.