Parotocinclus haroldoi

Parotocinclus haroldoi is described from coastal rivers of southeastern Brazil, a region within the Atlantic Forest biome that harbours numerous endemic loricariid species. The species has the moderately compact body form typical of the genus, with fine spotting or reticulation on the flanks and the characteristic ventral sucker disc of the Loricariidae. It is a social species found in groups in clear, well-oxygenated stream margins.

The rivers of southeastern coastal Brazil where P. haroldoi occurs are clear, relatively fast-flowing, and characterised by moderately soft to hard water depending on the underlying geology. These streams support productive algal growth on rocks and submerged wood, providing abundant food for grazing loricariids. P. haroldoi co-occurs with several other endemic catfish species in these Atlantic Forest drainages.

For aquarists, P. haroldoi is an appealing, lively Parotocinclus that performs well as a planted tank algae manager. Its care is similar to Atlantic Forest Otocinclus like O. flexilis — moderately cool, well-oxygenated water with good current and established biofilm. It integrates smoothly into communities of similarly sized peaceful species and contributes consistent algae management throughout the day.

Water: Soft to moderately hard at pH 6.0–7.5 and 20–26°C; good oxygenation; regular water changes. Tank: 60 litres minimum with plants, smooth rocks, and moderate flow. Feeding: Biofilm, algae wafers, blanched courgette, and cucumber. Breeding: Not documented in captivity. Compatibility: Excellent with small community species; well-suited to Atlantic Forest biotope setups.