Harlequin shrimps stand out very clearly in the aquarium mainly because of their body colouring. In the ground colour the animals are reddish. Their body is colored by light stripes, which can also show a tiger pattern in some shrimp. This varied pattern gives the harlequin shrimp their name, which is supposed to remind you of the costume of clowns.
However, the exotics from Indonesia are also easy to overlook. Because even larger shrimp of this genus are only about 1.5cm in size. This makes them the smallest freshwater shrimp you can find in an aquarium.
Harlequin shrimp are very busy animals. They love it when they can search for growing algae between aquarium plants or mosses. Mostly you can find them close to the bottom of the aquarium. They like to move on soft ground of sand or gravel. However, they only show themselves outside when they feel safe. On the other hand, if the shrimp notice even the slightest disturbance, they immediately take flight. It is therefore very important that the aquarium contains many places of retreat such as hollow stones, mangrove roots or bamboo sticks.
The clowns among the shrimps prefer it very warm in their environment. In the wild, they are found exclusively in Lake Towuti, which belongs to the Indonesian island of Sulawesi. The water temperature of the lake is never lower than 25°C, even in colder seasons. The harlequin shrimps therefore feel at home in a water temperature of 28°C to 29°C. The animals also need well-filtered water with a high oxygen content. To improve the quality of life it is very important that at least one third of the aquarium water is replaced once a week. This requires deionised fresh water, which is mixed with special minerals from the specialist trade. However, weekly cleaning of the aquarium is not absolutely necessary, as the animals also like to occasionally search for microorganisms or algae in the detritus to eat them.
Harlequin shrimp are rather gourmets. They are not satisfied with normal food such as brown autumn leaves or pieces of vegetables. The animals almost exclusively want to eat small, live starfish as food. If they don’t find any starfish, they sometimes look for growing algae. However, these are rather small appetizers for the shrimp than a real food source.
Occasionally the shrimp make do by looking for other aquarium inhabitants as emergency food. In their natural environment the animals would, for example, look for sea urchins to eat. However, fish and other shrimp do not attack them, so there is no danger of hungry harlequin shrimp eating the aquarium.
The breeding of Harlequin shrimp is basically simple. A female produces almost 20 eggs within one cycle. The larvae develop into young in the eggs and are released from the mother’s breeding room when they are mature.
As soon as the young shrimp are able to make their first movements, they take care of their food independently. In the early stages, the small harlequin shrimp will only eat growing algae and microorganisms. During this period, the shrimp are endangered because larger fish or crabs could easily regard them as easy prey. When the animals grow up, they switch to live food and then want to eat mainly starfish.
Providing the ideal living conditions for breeding harlequin shrimp is the big challenge. Compared to other shrimp species, fresh water is completely sufficient for breeding. But the procurement of food and the purchase of the special minerals for the water are together rather expensive. Beginners should therefore rather refrain from breeding their harlequin shrimp. For experienced breeders with the necessary sources of supply, however, it should not be too difficult to create the right conditions for the animals to reproduce successfully.
Harlequin shrimp are very peaceful on the one hand, but on the other hand they are also very shy. In the vicinity of fish, crabs or other strange inhabitants the animals feel uncomfortable and hide. A socialization is therefore only recommended with other shrimp in a species tank. The shrimp like to swim in groups of 10 to 15 individuals and are also open to other shrimp species. They can be socialised with, for example, gold spot shrimp, as they are native to the same region as harlequin shrimp.