title: [Organization of the parenchymula of the endemic Baikal sponge Swartschewskia papyracea (Dyb)].
abstract: The larva of the endemic Baikal sponge Swartschewskia papyracea freely swimming in water is a parenchymula which contains all main types of cells peculiar for the definitive sponge. Ultrastructure of these cells is described. Flagellar cells of the larva form a continuous layer with signs of polarity in distribution of organoids and inclusions specific for epithelial cells. Early specialization of collencytes secures, already at the larval stage, synthesis of a specific protein--collagen. Cytoplasm of blastomere-like nucleolar amoebocytes is overloaded with yolky inclusions at various stages of digestion. A developed Golgi complex is characteristic for this type of cells. Amoeboid cells with peculiar inclusions limited with a membrane and filled with a fine fibrillar material having central electron opaque granules are revealed.
mesh_terms: D000818:Animals; D007814:Larva; D008854:Microscopy, Electron; D011161:Porifera / Q000033:anatomy & histology* / Q000166:cytology / Q000254:growth & development; D012800:Siberia
vernacular_title: Organizatsiia parenkhimuly éndemicheskoĭ baĭkal'skoĭ gubki Swartschewskia papyracea (Dyb).