Abstract |
The brood-pouch (marsupium) of the oniscid isopod species Armadillo officinalis Dumeril 1816 (see Vandel 1955) (Armadillidae), Schizidium tiberianum Verhoeff 1923 (Armadillidiidae), and Porcellio olivieri (Audouin 1825) (Porcellionidae) was examined during their marsupial (breeding) period. In the first two species eggs, embryos and mancas are contained inside sacs which are suspended by a chord from the marsupium roof, whereas in the last species, eggs are connected singly each by a cotyledon. The thin wall of these marsupial sacs is a monolayered, flat epithelium consisting of cells rich in rough endoplasmic reticulum (RER), infoldings, mitochondria, and secretion vesicles. In its structure it is similar to that of the cotyledons. Both structures are probably active in secreting nutrients to the developing embryos. The evolutionary significance of this structure is discussed. |