European freshwater shrimps (Atyaephyra desmaresti) are an active representative of the genus dwarf shrimps. The colour variations are different. The body colouring varies from transparent to stronger colours such as brown, black and blue. A grey or pink tint is also possible.
European freshwater shrimp can change the body colour. Some dominant specimens have a darker colouring and are called “black knights”. The rostrum is equipped with movable spines (20 to 25). In the front part of the lower rim there are 5 to 8 larger teeth. The females can grow up to 4 cm, the males remain smaller. While the males are rather transparent, the colouring of the females is more intense. The life expectancy is between 12 and 18 months.
The sociable animals like to live in groups of 10 to 15 specimens. European freshwater shrimp should be kept in tanks with a minimum length of 60 cm. They need space to swim and run around. A dense green planting gives them the opportunity to hide. They like to use the plant thicket as a retreat during moulting. The water temperature for the adult animals should be between 15°C and 18°C.
They tolerate lower temperatures of up to 4 °C. Health problems occur at water temperatures above 25 °C. This genus can also be kept in garden ponds all year round. This is problematic during hot summer periods, but they survive the winter months without major problems. European freshwater shrimps do not place great demands on water quality. Nevertheless, clean, filtered and aerated water should be used in the aquarium.
These shrimp require oxygen-rich water. The soft to medium water quality should have a pH value between 6.0 and 7.8. These active animals can move quickly with their tail fans. There is a risk that they will jump over the water surface with their rapid reverse gear. This tragic accident can be prevented by a cover plate on the aquarium.
European freshwater shrimps are omnivores. They remove plant remains and graze the area with green algae. Their diet also includes detritus and dead animals. They eagerly keep the aquarium clean and prevent excessive algae growth. Fish in the shrimp’s habitat enrich the food supply with the remains of the fish food. Because they live together with fish, supplementary feeding is not absolutely necessary for freshwater shrimp.
This shrimp species particularly likes to eat autumn leaves (beech or oak). First the leaves are grazed and later the remains are completely removed. Additional feeding is necessary if the shrimp are kept in an aquarium without fish. A special shrimp food and twice a week suitable proteins are sufficient for the conservation needs.
European freshwater shrimps reproduce once a year. The females can produce up to 1,500 eggs between April and August. The brood is carried under the abdomen of the female freshwater shrimp. The reproductive period is known from the “shrimp life” in the wild. When kept in an aquarium, the reproductive behaviour can change. There are no seasonal influences and the environmental conditions in the aquarium are the same all year round. After four to six weeks the larvae hatch. They are only 6 mm in size. Further development takes place in the “parental” tank. The offspring loves a slightly warmer climate.
By slightly increasing the water temperature (room temperature) you can support the rearing. If there are no predators in the tank, the “little ones” can develop in peace. The freely swimming larvae are not threatened by the adult shrimp. Mechanical equipment should be protected by very fine nets or sponge filters should be used. This is to prevent the shrimp larvae from sucking in the water. For further development, larvae of the European freshwater shrimp need very fine food. The distribution of mulm on the bottom of the aquarium can support the search for food.
European freshwater shrimps are by no means aggressive towards their own species and other co-inhabitants. A socialization with other shrimp and invertebrate species as well as with fish is possible. European freshwater shrimp do not mix with other species of their genus. Peaceful co-existence works if no predatory or aggressive specimens of other genera are introduced into the tank.