Isopoda
Assel is a redirect to this article. For other meanings of isopod and isopods, see isopod (disambiguation).
The isopods (Isopoda) are an order belonging to the class of higher crustaceans (Malacostraca). Isopods range in size from 0.3 mm to nearly 50 cm. Most isopods are herbivores and thus biologically belong to the first decomposers.
The body of isopods, unlike the closely related amphipods, is flattened from the back to the abdomen. They have seven pairs of legs and a constant number of limbs. The gills are located on the rear legs. However, different species show different levels of adaptation to life on land, so in addition to gill breathing, there are also species with other respiratory organs such as tracheae or lungs.
The original habitat of isopods is the sea. However, they are also found in fresh water. One group - the terrestrial isopods - have left the water, but have retained their gill breathing throughout. The young develop directly from eggs in a gross pocket (marsupium) under the female's body. A female may have up to 100 young in a year. Because isopods must keep their delicate gill appendages constantly moist, they prefer moist habitats, but can also be found in dry areas. Thus, the woodlouse (Oniscus asellus) can be found in fallen leaves, under tree stumps and under stones. With their mouthparts (mandibles) they can eat fallen leaves and dead wood.
Species (selection)
- Woodlouse (Porcellio scaber)
- Cliff Assassin (Ligia oceanica)
- Woodlouse (Oniscus asellus)
- Armadillidium opacum
- Common woodlouse (Armadillidium vulgare)
- Giant isopods (genus Bathynomus)
- Aquatic sowbug (Asellus aquaticus)
- Cymothoa exigua
- Orthione
