青苔鼠 · Sucking 'Loach'

Overview

Frequently sold as a small algae cleaner, Gyrinocheilus aymonieri demands planning for adult size, longevity, and territorial behavior. Shy juveniles can become troublesome adults, chasing companions or attaching to their flanks. It is therefore a poor casual addition to a standard community.

Distribution & habitat

Its range spans the Mae Klong, Chao Phraya, middle and lower Mekong, and Dong Nai systems in Thailand, Laos, Cambodia, and Vietnam. The original description concerned material from the Samrong Tong mountains of Cambodia. Trade labels referring to India or China do not identify its native range.

Flowing tributaries and streams contain boulders, pebbles, gravel, sand, and submerged roots. Clear shallow water supports abundant growth on illuminated surfaces. Seasonal movements into deeper, cloudier water or temporary flooded areas are suspected.

Aquarium setup

Shelter is important, but decoration otherwise permits flexibility. A river layout with varied rounded stones, gravel, wood, and attached ferns or Anubias suits it well. Bright light encourages grazing surfaces to develop algae.

Maintain high oxygen levels, moderate current, and consistently clean water. Organic waste accumulation is poorly tolerated. Soft-leaved plants generally remain unharmed, although actual behavior should still be watched.

Diet & feeding

Surface grazing supplies algae together with small crustaceans, insect larvae, and other organisms. Visible aquarium algae should not be treated as a complete diet. Provide regular small live or frozen foods such as bloodworms, Daphnia, and Artemia alongside quality flakes, pellets, and vegetable items.

Shelled peas, cucumber, softened zucchini, spinach, and chopped fruit are useful additions. Mixed-ingredient gel foods offer another option. Settled fish may rise into midwater at feeding time while continuing to browse growth on stones in a stream-style aquarium.

Behaviour & compatibility

Territorial behavior intensifies with growth, especially toward similarly shaped fishes. Many bottom dwellers, including cichlids and catfishes, may be harassed. Even larger companions can suffer attachment to their flanks and feeding on body mucus.

For a mixed aquarium, favor robust active fishes occupying higher water. Adding this species last can reduce the chance that it claims the whole aquarium beforehand. Solitary housing is not the only possible arrangement, but careful selection is essential.

Groups can distribute aggression, provided there are at least six individuals and exceptionally spacious accommodation. A hierarchy develops, and small numbers leave weaker fish exposed to concentrated attention. This is not a project for a minimum-sized aquarium.

Sexual dimorphism

Mature females are fuller-bodied. Adult males develop conspicuous snout tubercles in breeding condition; juveniles cannot be sexed reliably by appearance.

Breeding

There is no established method for ordinary aquarium spawning. Large-scale commercial production uses hormonal assistance, which differs from routine home breeding.

Notes

Despite its common trade descriptions, it is not a true loach. Individuals can exceed 15 years, making long-term planning necessary. Ornamental forms include albino, golden, mottled, and short-bodied strains. Repeated dye injections have been used on some golden fish, causing harm and reduced longevity; artificial dyeing should not be mistaken for healthy coloration.

Members of Gyrinocheilus lack barbels and have accessory water-entry openings above the gill covers. These permit ventilation while the mouth remains attached to a surface for feeding or anchorage. The absence of barbels helps distinguish them from some superficially similar algae-grazing fishes.