Oniscus

Pronunciation

How to pronounce Oniscus: /oˈnɪskʊs/

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Summary

Oniscus asellus, the common woodlouse, is a widespread species native to Europe and common in the British Isles, known for its relatively large size and shiny brown/grey appearance. It plays an important role in ecological processes related to detritus decomposition.

Physical Characteristics

One of the largest native woodlice in Britain, up to 16 mm (0.63 in) long, relatively flat, and shiny brown/grey in colour; pale patches on the back store calcium for exoskeleton reinforcement after moulting.

Identification Tips

Look for a relatively large, shiny woodlouse with a flat body; pale patches are often visible on the back indicating calcium storage.

Habitat

Occurs in a wide range of habitats, including areas with little available calcium; commonly found under stones and on rotting wood; lives around items like rotting fenceposts, and is unique in inhabiting heather moors and blanket bogs.

Distribution

Widespread in the British Isles, Northern and Western Europe, as far east as Ukraine, in the Azores and Madeira; introduced widely in the Americas, predominantly in Mexico and the United States, east of the Mississippi River and west of the Rocky Mountains.

Diet

Detritivore, feeding on decaying plant material.

Life Cycle

Moulting occurs in two halves, with the rear half moulting before the front half.

Ecosystem Role

Plays a role in the decomposition process by contributing to the breakdown of organic matter.

Collecting Methods

• Hand collection in natural habitats

Preservation Methods

• Ethanol preservation
• Dry preservation

Similar Taxa

• Other species of woodlice within the family Oniscidae

Tags

• Oniscus
• woodlice
• common woodlouse
• isopoda
• European fauna