Asellus aquaticus

Isopods ( Asellus aquaticus )

The water louse ( Asellus aquaticus ) is a living in freshwater species from the order of the isopods.

Most species of isopods live in the sea, comparatively few occur on land or in fresh water. In the inland waters of Central Europe there are two or three species, of which the water louse is the only east of the Rhine.

Features

The water isopod is 10 to 20 millimeters long. The males are larger than females. At the head of water lice sit two eyes and two pairs of antennae. A couple is almost legs long, the other short.

Reproduction

The females lay up to 100 eggs that are carried in the brood sac. The young lice swarm out after 3 to 6 weeks and are already similar to adult animals.

Habitat

Water lice hold on in standing and in slow-moving waters. They feed on decaying plant debris, make no great demands on water quality and are very durable. They can survive for some time at very low oxygen concentrations or even under anaerobic conditions at high oxygen depletion in the water. The water isopod is a Leitorganismus for heavily soiled waters of the water quality class III. Drying her living waters from, they bury themselves in the mud. You can find a whole year on the isopods, also at the bottom of an icy waters.

Behavior

Isopods not use their legs for swimming, but move away by running. They live on the ground or climb on aquatic plants. The animals seem slow, but can be very nimble them in danger. You can withstand a stronger flow and migrate against the direction of flow. In waters with flow rates of more than 5 centimeters per second, it does not settle in permanently. This is but mainly because the flow conditions allow here no sufficient deposits of dead plant parts as a food source for the water lice.

Like other residents of the macrobenthos they serve in the food chain often as food for larger fish. They can transmit the disease to scratch the fish when they accommodate themselves scratch worms ( Acanthocephala ).

Water pipes

Isopods are among the organisms that can colonize potable water in areas with poor water quality. They feed on eingeschwemmtem organic material and break down the biofilms that can form on the walls of the pipes. Increased proliferation of water lice is therefore an indicator of increased pollution of the water. By isopods itself there is no health risk. When control measures must be taken to ensure that the bacteria, fungi and protozoa in the biofilms grow no faster after washing out of the water lice than before.