Isopods

'T* I IK ORDKR ISOPODA consists of X 100 families and 10,000 species of crustaceans. Most isopods arc marine. However, 32 families (3,800 species) belong to a suborder called Oniscoidea and are amphibious or live in terrestrial habitats. They arc known collectively as woodlice. Wood I ice have a segmented, flat body with seven pairs of similarly shaped and sized legs. The female carries the eggs inside a brood pouch, which is located beneath the abdomen. The young arc kept in this pouch for a while after they hatch out.

Most woodlice favor damp and cool conditions, although some have become adapted to a wide range of habitats, including extremely dry regions. Some woodlice have camouflage coloring that blends with their background.

0rder ISOPODA

Family ARMADILLIDIIDAK

Pill woodlice

Also called pill hugs, these woodlice are convex in cross section, with a rounded hind margin. Many can roll up into a ball for protection.

• I JFK CYCLK The eggs arc carried in a brood pouch until they hatch. As in many woodlice, the newly hatched young have one less pair of legs than the adults. The mother may provide her young with some protection.

• OCCl IRRKNCK Europe and the Mediterranean. In places such as leaf litter and debris.

curled up for protection j* segments of outer casing overlap

ARMADH.udum s ALBUM is pale with dark markings and lives in salt marshes and coastal areas. It does not form as tight a ball as the pill millipede (see p.242) when it rolls up.

Length _i ¡n (0.5-2.5em)

Feeding habits ^ j ^ ^^

Order ¡soPODA

Family poRCKLLIONIDAE

No. of species ^qq

porcellionids

I he smooth or warty body surface of these woodlice is usually either gray or grayish brown, with various other markings. Some species of porcellionid have narrower bodies and are able to run quickly.

• LIFE CYCLE The females carry the eggs in their brood pouch until they hatch.

• ( )( :< A KKF.V IF. \\< h It Iw iilc, hui m.link in temperate regions. Found mostly in leaf litter and debris.

• REMARK As with all woodlice, nitrogenous wastes are excreted as ammonia gas - not as urine. This gives large colonies of woodlice a characteristic smell.

grayish brown • body warty body « surface grayish brown • body warty body « surface

VORCll.LH) SCAIil li is a widespread species. It is usually a grayish color, but orange and cream forms are often found in coastal regions.

Arachnids

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