title: [Observation on eggs of Oncomelania hupensis hupensis with scanning electron microscope].
abstract: OBJECTIVE
  To observe the structure of the mud hull packed Oncomelania eggs and the surface structure of colloid membrane called the third grade membrane of eggs.
  
  
  METHODS
  Scanning electron microscopy was used to observe Oncomelania snail eggs with integral mud hull collected from eastern Dongting Lake.
  
  
  CONCLUSIONS
  The mud hull of eggs was made of unshapen small humification combined with earth granules with a diameter of 2.6-9.2 microns. The mud hull in 60 um thickness was honeycomb-like in shape with many small holes and small folds on the wall. There were many round or irregularly round hollownesses on the inner layer of mud hull that contacts colloid membrane but no hole through mud hull. There were some protein fiber networks covering on the colloid membrane and apophysis. The structure of the mud hull showed that the exchange of matter was maintained between eggs and outside, and the mud hull is of great importance to regulating temperature and moisture for the growth of eggs by preventing hydrosoluble substances from penetrating into eggs. The protein fiber networks act on gluing mud hull and buffering outside power. The dense glue membrane might be a main barricade to prevent pharmaceutical molecules from penetrating into eggs.
authors.affiliation: Hunan Institue of Parasitic Diseases, Yueyang 414000.
authors.forename: Q B
authors.initials: QB
authors.lastname: Xia
authors.forename: Y B
authors.initials: YB
authors.lastname: Yuan
authors.forename: B
authors.initials: B
authors.lastname: Liu
authors.forename: P P
authors.initials: PP
authors.lastname: Tan
mesh_terms: D000818:Animals; D008855:Microscopy, Electron, Scanning; D010063:Ovum / Q000648:ultrastructure*; D012908:Snails / Q000648:ultrastructure*