Chinese Algae Eater

About

The Chinese algae eater (Gyrinocheilus aymonieri) is one of the most widely sold freshwater fish in the hobby, yet it's also one of the most frequently misrepresented. Juveniles are small, harmless-looking, and genuinely useful at tackling algae, but the fish people bring home and the fish they end up with a few years later can feel like two different animals. Native to the river systems of mainland Southeast Asia, the Mekong, Chao Phraya, and Meklong basins among others, it naturally clings to hard surfaces in flowing water, using its sucker-like mouth to rasp algae and periphyton while a clever spiracle opening on each gill cover lets it keep breathing without releasing its grip. That mouth becomes a problem in the aquarium as the fish ages: adults are known to latch onto the flanks of larger tankmates and feed on their body mucus, and they can be intensely aggressive toward anything with a similar body shape, including Crossocheilus, Epalzeorhynchos, and Garra species. Bottom dwellers of all kinds tend to bear the brunt of this behavior. All fish in the trade are commercially farmed, and several color variants exist, though artificially dyed individuals are best avoided entirely. With a lifespan potentially stretching past a decade, this is a fish that demands realistic long-term planning.