Remarks: Orange otos (Nannoptopoma sp., formerly Hypoptopoma sp.) are small, algae-eating fish from South America. They have been called orange zebra otos, Robocop otos, and several other names. They are a very uncommon species with not too much known about them. This species rarely grows larger than 1.5" long and has an attractive pattern of thick, dark brown or black vertical bands along their white or cream colored bodies. When kept in proper conditions, they tend to take on a beautiful orange hue that stands out nicely against green plants.

   Orange otos require a plentiful amount of algae to graze on as they have extremely fast metabolisms. This appetite makes them do a remarkable job cleaning leaves, wood, rocks, and glass of green and brown algae. They rarely accept prepared foods, so having a tank with well-established driftwood or stones covered in algae and aufwuchs will be very beneficial to their long term health. Providing fresh and blanched vegetables such as zucchini, spinach, or green beans can be a good way of getting them to eat if algae becomes scarce. 

  As this species doesn't have much in the way of defense and is very small, orange otos should not be kept with aggressive species or those big enough to swallow them. They also require high levels of dissolved oxygen and do not tolerate poor water quality so heavy filtration and frequent water changes are a must. If a tank has high flow, it can be very entertaining to watch them play in the current.