Observation on The Eggshell of White-Fronted Shearwater With Scanning Electron Microscopy

White-fronted Shearwater (Puffinus leucomelas) breed on the islands near Qingdao,Shandong Province.This present paper deals with our study of the eggshell ultrastructure with scanning electron microscopy and the elements with TN-5500 energy spectrometer.The eggshell is mainly composed of 5 layers and Ca,P,K,Cl elements.The eggshell membrane layer can usually be divided into 2 layers,inner and outer membranes.Under the scanning electron microscopy,the inner surface of the membranc appears profuse mat fibres with some bud projections.They interweave into net and arrange in many layers.The mammilary cone is composed of petal and basal body.The bodies could be divided into mushroom and polygon forms.The polygon cone body has some petals projected from the core,and there is no petal on the mushroom.They arrange into different orientations,and the eggshell membrane be adhere on to the cones.The distance between the cones are different.The mammilary cone basal layer is a foundation of cone and denser than spongy layer.The spongy layer is the hardest part of the eggshell.It is composed sedimentary rock structure that the calcite deposit crystal into organic layers.There are many air pores in the spongy layer which open into the outer layer and the space between cones.The pore tube is composed of inner membrane and outer calcite tube.The embryo exchange air with the environment by these air pores.There are some pores mouths on the outer layer,and the surface of eggshell is rough with many projections.There is a protein membrane producted by oviduct to protect from bacterium and water loss.