Hassar orestis · Black-top Mouse Catfish

Overview

The retiring doradid Hassar orestis does best with company of its own kind and substantial cover. Newly imported fish can be fragile. Look for a rounded abdomen and normal eyes: a hollow belly or sunken eyes indicate severe wasting, whereas healthy fish usually become robust after settling.

Distribution & habitat

Records span northern South America, including Ecuador, Colombia, Venezuela, Guyana, Peru, and Brazil. Slow tributaries, swamps, standing waters, and coastal mangrove habitats provide roots and flooded vegetation for shelter.

Aquarium setup

Offer many retreats, particularly thick plant growth, which it appears to favor over hard decor alone. Subdued light encourages activity outside cover. Reliable filtration and careful maintenance matter because deteriorating water conditions are poorly tolerated. Its activity level is modest relative to its size.

Diet & feeding

New arrivals may accept only small items such as bloodworms, Daphnia, and fine dry granules. Settled fish become less selective and more confident, often moving around the aquarium when food is offered.

Behaviour & compatibility

Keep at least three to encourage confidence. Most companions other than extremely tiny fishes are safe, although its size may intimidate small, placid bottom dwellers. Characins or hatchetfish using other levels, suitable cory catfish, and many loricariids are easier combinations. Avoid substantially larger or strongly territorial companions that could dominate it.

Sexual dimorphism

Males develop an extended leading dorsal-fin ray. Female pectoral fins have a rounder outline.

Notes

The similar Nemadoras leporhinus has longer leading fin rays and a transparent dorsal fin marked dark at the base. This catfish can make audible sounds through pectoral-spine friction and swim-bladder vibration. Handle nets carefully because the pectoral spines readily catch in the mesh.