Otocinclus Catfish

Otocinclus have a sucker-disc mouth that works less like a vacuum and more like a scraper, rasping algae films off leaves and glass with rows of tiny comb-like teeth — and unlike a lot of 'algae eaters' sold at that size, they actually keep eating algae as adults instead of switching to a general omnivore diet. That makes them one of the few fish in the hobby genuinely worth the label 'algae crew.'

Care level: Moderate · Temperament: Peaceful, shoaling · Max size: ~2" · Min tank: 10 gal · Diet: Herbivore, algae + supplemental algae wafers