Red Cherry Shrimp (Neocaridina heteropoda)

These aquarium shrimp are primarily algae eaters. They will eat any food intended for aquarium use, but some will prefer compressed algae discs. 

Neocaridina heteropoda or cherry shrimp is a species of freshwater shrimp commonly kept in aquariums. Full-grown cherry shrimp reach about 4 cm (1.5 in) in length. They prefer clean water, with a pH of 6.5-8, and a temperature of 18-30°C (65-85°F). Cherry shrimp are omnivores that may live 1-2 years.

Housing
Red cherry shrimp are fairly easy to care for in the home freshwater aquarium. They will adapt to a wide range of water conditions, and will thrive in the same conditions as many common aquarium fish. A few cherry shrimp can be kept in a desktop aquarium of 1-2 gallon capacity, and a setup of 10 gallons or more will allow for an active colony.

The aquarium shrimp spend a great deal of their time sitting on aquatic plants, when available, and hiding in them for protection, especially after molting. They also eat the film of algae and microorganisms which forms 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 that the cherry shrimp do, and provide both the physical benefits of the plants to the pet shrimp and pleasing visual contrast with the red bodies of the pet shrimp to the human viewer.

This aquarium shrimp also respond to the color of their background and substrate. If they are in a tank with light-colored substrate, they will become paler, even transparent. On a darker substrate, they take on their full red coloration.

Like most aquatic invertebrates, Red Cherry Shrimp are very sensitive to ammonia buildup in their water. They should never be put into a tank which has not been fully cycled, and regular testing should be done on any new tank until it is certain that the tank is stable. Even trace amounts of ammonia can weaken or kill shrimp, so aquarium cycle control is critical. The usual causes of ammonia spikes are overfeeding leading to uneaten food decaying in the tank, insufficient denitrifying bacteria, and overcrowding by shrimp, fish, or both.

It is important to note that, like most freshwater invertebrates, Red Cherry Shrimp are extremely sensitive to copper!. Therefore, if copper-based treatments for the external parasites of fish are used in a tank containing cherry shrimp, the shrimp should be removed for the duration of the treatment and until the copper has been cleared from the water. It is advisable to use a copper test kit (available from specialty aquarium stores and suppliers) to confirm this.

Some shrimp breeders advise adding small amounts of the iodine supplements sold for saltwater tanks to a tank of cherry shrimp; others say it is unnecessary or even harmful. There is at present no general consensus on iodine supplementation.

Behavior
The Red Cherry Shrimp is a non-aggressive shrimp. They are active during the day, and can be seen grazing on algae on aquarium decor 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 pet shrimp will eat it to recover the valuable minerals it contains.

Diet
The Aquarium Shrimp are known as algae eaters. They will eat any fish food, but some will prefer algae or spirulina-based fish food.  Blanched (boiled until soft) vegetables such as zucchini, baby carrots, and spinach can be used as a supplemental food, but should be fed sparingly. Uneaten vegetables can very quickly decompose and create water quality problems.

Sexing
The male is smaller and less colorful than the female. The male's tail, not being needed to carry eggs, is thinner. The female is larger and displays a much darker and more extensive red color, and often has a "saddle" marking of developing eggs.

Breeding
Breeding Red Cherry Shrimp is as simple as putting an adult male and female together in an aquarium. You can observe the eggs developing in the female's ovaries as a white or yellow triangular "saddle" marking on her back. When she is ready to lay the eggs, she releases pheromones into the water to signal her availability to males. The male shrimp in the tank will often become agitated, swimming very actively about as they search for the source of the pheromones. After a brief mating process, the female lays her eggs and affixes them to her swimmerettes.

When the young hatch, they are tiny (~1 mm) copies of the adults. They have no planktonic larval stage. They spend their first few days of life hiding among plants, where they are almost invisible, nibbling on the biofilm on the plants. They then emerge and graze on algae on tank surfaces and ornaments.

Tank Mates
These Aquarium Shrimp are very small and harmless, meaning that any carnivorous or omnivorous fish is a possible risk to them. Even fish too small to eat an entire shrimp can harass them, pick at their legs, etc. Newly hatched shrimp are so tiny that nearly any fish can, if so inclined, eat them. Therefore, if you intend to breed them, they should have a tank to themselves. Small, non-aggressive fish such as neon and cardinal tetras, otocinclus catfish, and possibly strictly vegetarian species of killifish, can be kept with cherry shrimp. Cichlids, barbs, and similar fish will eat them.

Availability
The Cherry Shrimp has become widely available in the United States and Europe and can now be purchased over the Internet, at aquarium stores, and from private breeders, especially through local aquarium societies.