Fishnet Algae-eater Care Guide - Tank Setup, Diet & Breeding

The Fishnet Algae-eater, Crossocheilus reticulatus, is a streamlined freshwater cyprinid with a distinctive net-like pattern. Dark markings form a reticulated mosaic across the pale gold, silver or olive-brown body, while the fins are generally translucent and the underside is lighter. Its mouth is adapted for grazing surfaces rather than hunting prey.

This active species spends much of its time moving across rocks, wood and other firm surfaces in search of aufwuchs. It is an energetic swimmer and can be entertaining to watch as it investigates the aquarium, although it is less likely to remain still than many small community fish.

In the wild, Fishnet Algae-eaters are associated with clear, well-oxygenated streams and rivers. Flowing water continually brings nutrients and exposes algae, biofilm and tiny invertebrates on stones and submerged wood. Their body shape and sucker-like grazing mouth reflect this specialised habitat.

They are generally peaceful, but adults can become assertive when competing for food or space, particularly in cramped aquariums. Compared with some similarly named algae-eaters, this species is best regarded as a medium-sized, active river fish rather than a tiny maintenance fish for a small tank.

Fishnet Algae-eaters are native to mainland Southeast Asia, including parts of Thailand, Laos, Cambodia and possibly adjacent areas of the Mekong and Chao Phraya drainage systems. They inhabit flowing freshwater streams and rivers, particularly areas with rocky surfaces and good oxygenation.

A group should have at least 150 litres, with a tank around 120 cm long preferred so these active swimmers have adequate horizontal space. Use a broad layout with smooth sand or fine rounded gravel, substantial open swimming room, and smooth stones, driftwood and hardy plants for grazing surfaces and shelter. Strong filtration, excellent oxygenation and a moderate current are important, while secure covers are sensible because active Crossocheilus can jump. Regular maintenance should preserve clean, stable water without removing every natural biofilm-covered surface.

Up to about 15 cm (6 in) in total length. Females are usually deeper-bodied and may be slightly larger than males.

The natural diet consists largely of algae, aufwuchs, biofilm and small organisms living among it. Offer a varied diet of algae wafers, sinking vegetable-based pellets, blanched courgette, spinach or cucumber, supplemented with quality sinking foods and occasional frozen or live foods such as bloodworm, daphnia or brine shrimp. Do not rely on naturally growing algae alone, especially in a mature group, because inadequate nutrition can lead to wasting and competition.

Fishnet Algae-eaters suit peaceful community aquariums containing similarly sized barbs, danios, rasboras, larger tetras, peaceful rainbowfish and other non-aggressive river fish. They should not be housed with large predatory cichlids, fin-nipping species or excessively boisterous tankmates. Keep an appropriately sized group so social interaction is spread between several fish, while providing enough floor and swimming space to reduce competition. They may show occasional rivalry with other algae-grazing cyprinids in a confined aquarium.

Fishnet Algae-eaters are not commonly bred in home aquariums. Their natural spawning behaviour is poorly documented, and successful commercial production generally relies on specialist facilities and controlled hormonal techniques. A mature aquarium may encourage natural courtship, but there is no dependable home-breeding method; eggs and fry would also be vulnerable to filtration and other fish.

Females are generally fuller through the abdomen and slightly larger once mature. Males tend to be slimmer, but the sexes are otherwise difficult to distinguish reliably without comparing adult fish in good condition.