Cherry Shrimp (Red Cherry Shrimp)

About the species

The cherry shrimp (Neocaridina davidi) is a tiny, active shrimp for the freshwater tank – not a crayfish and not a "crab", but a true member of the infraorder Caridea, the same group as the better-known Amano shrimp. Sold under names like "cherry shrimp" or "red cherry shrimp", it comes in several bred colour strains of the same species.

A shrimp, not a crayfish

The mix-up with crayfish is common, but taxonomically these are entirely different animals. Freshwater crayfish, such as the invasive red swamp crayfish or the signal crayfish, belong to the infraorder Astacidea and are considerably larger, with prominent claws and a heavy armoured shell. The cherry shrimp belongs to the infraorder Caridea, family Atyidae – smaller, without prominent claws, and with a body that curves into a characteristic "C" shape when swimming. The wild population comes from freshwater habitats in China, Korea, Taiwan and Vietnam, where it lives in slow streams and ponds ranging from just a few degrees in winter to nearly 30 °C in summer.

Tank, water and parameters

A small group can live in a tank of about 20 litres, but 30–40 litres or more is recommended for more stable conditions, since a smaller water volume swings faster and that is riskier for such a small animal. It tolerates a fairly wide temperature range (roughly 18–26 °C) and pH (roughly 6.5–7.5), but needs adequate general hardness (GH), since it draws on the calcium and magnesium in the water to build a new shell after every moult. In water that is too soft or too acidic, moults fail more often. The shrimp is extremely sensitive to copper – even trace amounts from algae or snail treatments can be lethal, so care is needed when medicating other animals in the same tank.

Breeding without a larval stage

Unlike some other aquarium shrimp (the Amano shrimp, for instance), the cherry shrimp needs no salt or brackish water to breed. The female carries fertilised eggs under her abdomen ("berried", in hobbyist terms) until, after several weeks, they hatch as miniature copies of the adults – no free-swimming larval stage that would need separate rearing. That makes it one of the easiest species to breed in a home aquarium; given enough food and no predators, a colony sustains and expands itself.

Living with fish

The shrimp is peaceful and threatens neither plants nor other animals, but it is itself frequently prey. Most fish larger than the shrimp will eventually try to eat it, and the young are vulnerable even to fairly small species. It does best in a shrimp-only tank or alongside genuinely peaceful, tiny tankmates (some small catfish species, for example); with distinctly predatory or territorial fish, cohabitation is risky for the shrimp population, not for the tank itself.

Why it is not on the invasive species list

The cherry shrimp is not on the EU's list of invasive alien species of Union concern (Regulation (EU) 1143/2014) – among crustaceans, that list covers species such as the red swamp crayfish (Procambarus clarkii) and the marbled crayfish (Procambarus virginalis), not freshwater shrimp of the genus Neocaridina. That said, the species is documented to have survived, after aquarium releases, as small isolated populations in a handful of warm, often thermally-influenced waters in Europe (for example in Germany, Hungary, Poland and one stream in Slovakia). That is one more reason never to release shrimp, or any aquarium animal, into natural waters, even a species that looks harmless.

Pros & cons