The blue Gabonese fan shrimp or blue monster fan shrimp ( Atya gabonensis )are among the most interesting invertebrates in the aquarium. The name indicates the most obvious characteristics:
- “Blue”: striking body colour
- “Gabon”: original homeland Gabon in Central Africa
- ” Fan-shaped hand”: describes the two fan-shaped scissors
- ” Monster”: names the above average size of up to 16 cm
The most impressive features of the fan shrimp are the fan hands with the bristles. These developed from the two shears in the course of evolution. They give it the ability to fish food particles from the water.
It also has a strongly developed third pair of legs. With them they can hold on to the bottom even in strong currents and at the same time catch the particles floating around. To clean the dirty compartments they simply fold them up and clean them with their mouth parts.
Both sexes show a strongly folded surface of the rear shell, the so-called carapax. On the other hand, the legs and belly shields of the male are much stronger than those of the female.
The blue body colouring of the Gabonese fan shrimp can be different. It often acts as a mirror for the condition of the habitat and the state of health. The blue colour can change with poor husbandry conditions, stress with other aquatic animals, moulting and with increasing age. In these cases it becomes lighter or darker and receives orange, brownish or light beige colour parts.
Under ideal conditions in the aquarium, the blue monster fan shrimp quickly acclimatizes. They are sociable, absolutely peaceful and easy to care for. Sometimes they show a territorial behaviour and it can come to disputes with conspecifics about the best place. These small tiffs are easy to avoid with sufficient seating.
This shrimp species is not only one of the most visually impressive, but also one of the most active in the aquarium. In order to prevent its size from becoming an obstacle for the shrimp and to allow it to swim and fish for particles, it requires a tank with at least 80 litres.
The optimal fan shrimp aquarium is moderately densely planted and not overcrowded. If the bottom is given a dark background, the blue colour is particularly effective. For resting, observing and fishing it needs well secured places. These can be stones, ceramic shards and root wood. They like to sit there, stretch out their heads and direct their fan hands against the water current. To support them in their activities, a prudent aquarium keeper will install a strong ventilation system for good oxygen supply and flow conditions.
As the shrimp are mainly active at dusk and at night, they sleep during the day. Sufficient safe hiding places must be available for the resting periods. Recommended are: walkable caves, inverted, open shells, open tubes and broad-leaved plants.
Last but not least a good water quality ensures the health of the animals:
- Temperature: 24 to 28° Celsius
- pH value: 6,5 to 8,0
- Total hardness: 6 to 20° dGh
- Carbonate hardness: 3 to 12° dKh
The conductance is 400 to 850µS
The Blue Gabonese fan shrimp feed mainly on the suspended particles of detritus and algae. Special food is recommended, which is beneficial to fan activity and is filtered out by the shrimp. This food must float in the water, be distributed by the current and must not sink to the bottom too quickly.
Suitable varieties include the following: Dust food, flake food and powder food. Special food pastes can also be attached to the aquarium. These dissolve slowly in the water and the individual parts get into the current.
The breeding of the blue Gabonese fan shrimp is not possible in a freshwater aquarium, because it belongs to the primitive reproduction type. In the wild they spawn exclusively in brackish water. The Zoe larvae hatching from the eggs need seawater for their development and swim out to sea with the current after hatching.
Should the shrimp species nevertheless be allowed to mate and reproduce in a suitable aquarium, the female will carry a large number of eggs. The gestation period is between 5 and 6 weeks.
The age expectancy of the large animals is about 2 years.
Like most relatives, the blue Gabonese shrimp are sociable and peace-loving. They are among the optimal inhabitants for a stream biotope aquarium. They get along well with the much smaller dwarf shrimp, peaceful and current-loving small fish such as fin-sucking or mosaic gourami. They can also live together with filtering piano snails or Brotia herculea.
However, the large size must not lead to a socialization with other large animals such as large shrimps or large American crayfish.