Otocinclus affinis is hard to find during the day. There favorite plant seems to be the Vallisneria gigantea. At the moment there is only one Otocinclus in the tank.
Otocinclus affinis
Loricariidae, Hypoptopomatinae
Habitat: South America
(Southeastern Brazil)
Length: up to 1,5 inch (3,8 cm)
Temperature: 68-79 °F (24-26 °C)
pH: 5-7,5
DH: 2-15°