Asellus aquaticus
FAMILY
Asellidae
TAXONOMY
Asellus aquaticus Linnaeus, 1758, type locality not specified.
OTHER COMMON NAMES
English: Hog slater, hoglouse; French: Aselle, cloporte d'eau; German: Wasserassel.
PHYSICAL CHARACTERISTICS
Individuals are brownish and have long, oval, dorsoventrally flattened bodies. Some have two yellow, fluorescent stripes down their backs. Males are typically larger than females, reaching approximately 0.8 in (20 mm). Individuals that live in caves and other dark environments are unpigmented and have no visible eyes.
DISTRIBUTION
Europe.
HABITAT
A freshwater isopod, the water louse lives primarily in surface-water areas, including ponds and slow-moving creeks. Researchers have found well- and cave-dwelling populations of this species.
BEHAVIOR
The male guards its intended mate for several days before fertilization by hoisting up the female from the substrate and carrying her underneath him. Unpaired males sometimes are successful in attempts to take the place of mating males by struggling with and separating united pairs.
FEEDING ECOLOGY AND DIET
The diet includes coarse, particulate, vegetative matter taken from the sediment.
REPRODUCTIVE BIOLOGY
Water lice reproduce from early spring to mid autumn. Observations differ on whether males prefer larger females. Heftier females produce more and faster-hatching eggs but are a heavier load for males to carry during the precopulatory, mate-guarding period. Males that choose larger females may cut back on precopulatory mate guarding and carry the female nearer to her fertile period, which occurs during her final molting.
CONSERVATION STATUS
Not listed by the IUCN.
SIGNIFICANCE TO HUMANS
None known.
