The
marsupium or
brood pouch, is a characteristic feature of
Peracarida, including the orders
Amphipoda,
Isopoda and
Cumacea. It is an egg chamber formed by
oostegites, which are appendages which are attached to the coxae (first segment) of the first
pereiopods. Females lay their eggs directly into the brood chamber, and the young will develop there, undergoing several
moults before emerging as miniature adults referred to as
mancae. Males have no marsupium.