Arnold's Otocinclus (Otocinclus arnoldi) Care Guide
Otocinclus arnoldi is a small dwarf suckermouth catfish from the lower Paraná and Río de la Plata, a peaceful shoaling algae grazer for mature, planted tanks.
Overview
Otocinclus arnoldi is a dwarf suckermouth catfish of the family Loricariidae (subfamily Hypoptopomatinae). FishBase lists a maximum standard length of about 4.8 cm.
Taxonomy
- Family: Loricariidae
- Scientific name: Otocinclus arnoldi
- Subfamily: Hypoptopomatinae
- Common synonyms: Arnold Oto
Habitat
FishBase records the species from the lower río Paraná drainage, the lower and middle río Uruguai, and the río de la Plata. Otos are diurnal shoalers of small streams and well-oxygenated river margins, grazing the film on wood, stones and broad-leaved plants, and possess an air-breathing adaptation.
Tank requirements
- Minimum tank volume: 60 L (16 gal)
- Adult size: 3-4 cm (1.2-1.6 in)
- Temperature: 24-28 °C (75-82 °F)
- pH: 6-7.5
- GH: 2-12 °dGH
- Group size: ≥6 individuals
- Lifespan: 8-12 years
Diet
The diet is algae-based, dominated by diatoms and aufwuchs. The fish does best in a mature, planted aquarium with a steady supply of soft green algae and biofilm, supplemented by blanched vegetables and algae wafers. Animal foods are a minor part of the diet.
Compatibility
A peaceful species easily outcompeted for food, it requires calm tankmates. It is a social shoaler best kept in groups of at least six and is plant-safe, suiting communities of small tetras and Corydoras.
Breeding
In keeping with the genus, it lays adhesive eggs that are not guarded, depositing them on plants and aquarium surfaces.
Conservation status
The IUCN Red List assessed the species as Least Concern (2020).