Ghost shrimp

Ghost shrimp, also sold as glass shrimp or grass shrimp, are small, almost transparent freshwater shrimp from the slow streams and lakes of the southeastern United States. They reach about 3 to 4 cm and can move the pigment around in their bodies to blend into whatever is behind them, which is where the 'ghost' name comes from. They are cheap, widely stocked, and often sold as live food, so they get treated as throwaway animals; kept properly, though, they are active, hardy, and a genuinely useful part of a cleanup crew.

During the day they pick at algae, biofilm and leftover food, and they get noticeably busier toward evening, since they are natural night-foragers that tuck into plants when the lights are bright. They are peaceful and shrimp-safe, and they get on with any calm fish too small to treat them as a snack, such as small tetras, rasboras and corydoras; larger or aggressive fish will just eat them. Because they are so tough once settled, they often get recommended as a first shrimp. The catch is that feeder-tank stock frequently arrives stressed and underfed, so slow acclimation and steady water quality do most of the work in keeping them going.

Aim for roughly 18 to 28°C and a pH around 6.5 to 8.0 in clean, well-filtered water; like all shrimp they react badly to copper and to ammonia spikes. Keep them in a group rather than alone, as they are sociable foragers. Their life is short, usually about a year, and adults often fade not long after a spawning season. Ghost shrimp will breed in freshwater, but the hatchlings are tiny and free-swimming and need infusoria-grade food, while the adults will happily eat them, so raising a brood realistically means a separate, densely planted tank.