Neocaridina davidi (Freshwater Shrimp) from Taiwan is commonly kept in aquaria. The natural colouration of the shrimp is green-brown. There is a wide range of colours such as red, yellow, orange, green, blue, violet, black, etc., however, the red morph is more frequently sold. The density of colouration on adult shrimp, dependent on breeding, determines their sale price and «quality» (grading). This «quality» is purely aesthetic, as the size, behaviour and other characteristics of the animal are more or less equal across varieties. Full-grown shrimp reach about 4 centimetres long. Neocaridina davidi shrimp are omnivores that may live 1 – 2 years.
Neocaridina davidi shrimp are easy to care for in the home freshwater aquarium and breed well. They will adapt to a wide range of water conditions and will thrive in the same conditions as many common aquarium fish. Neutral to slightly alkaline pH, with zero ammonia and nitrite as well as low nitrate, gives the best results. A cooling system is recommended in warm climates. A few Neocaridina davidi shrimp can be kept in a desktop aquarium of 4 – 8 litres capacity, and a setup of 40 l or more will allow for an active colony. A planted tank is most comfortable for the shrimp and the plants provide cover for adults and young. Plants also provide more surface area to grow biofilm for shrimp to graze on.
The shrimp spends a great deal of its time sitting on aquatic plants, when available, and hiding in them for protection, especially after moulting. They also eat the film of algae and microorganisms that form on plant leaves without harming the leaves in the process. Java moss and Java fern are both excellent plants for the shrimp tank, as they thrive in the same conditions as the Neocaridina davidi shrimp and provide both the physical benefits of the plants to the shrimp and aesthetics to human viewers. Young shrimp spend much of their early life hiding among plants and feeding on microorganisms and tank algae.
Neocaridina davidi shrimp respond to the colour of their background and substrate. If they are kept in a tank with the light-coloured substrate, they will become paler, or even transparent. On a darker substrate, they take on their full colouration. Colour intensity also depends on the types of food available (live foods and those high in protein and fats are more beneficial than flake foods), water pH, and temperature.
The Neocaridina davidi shrimp is a non-aggressive shrimp. They are active throughout the day, and can be seen grazing on biofilm, aquarium décor or the sides of the tank, hunting detritus among the gravel, and sometimes even mating. Periodically, a shrimp will shed its exoskeleton, leaving an empty white ghost of itself caught in the plants or drifting around the tank. This should be left in the tank, as the shrimp will eat it to recover the valuable minerals it contains. There have been some reports by people of some shrimp attacking other vulnerable shrimp or fish, possible explanations have been insufficient protein in their diet or just general insufficiency of biofilm in the tank.
Female pregnant Neocaridina davidi shrimp tend to hide in the dark. If they feel endangered by predators, they will abandon their eggs. They need an environment with wood or plants such as Java Moss in which to hide themselves and their babies. When they are carrying the eggs under their bodies, they can be witnessed circulating water over the eggs with their pleopods (swimming legs) to ensure good health.