白冠长尾雉(Syrmaticus reevesii)卵壳的超微结构及元素组成研究

THE ULTRASTRUCTURE AND ELEMENTAL COMPOSITION IN EGGSHELL OF THE REEVE'S PHEASANT (SYRMATICUS REEVESII)

对采自河南董寨国家级自然保护区的白冠长尾雉（Syrmaticus reevesii）卵壳样品进行了检测和研究，利用扫描电子显微镜观察了卵壳的超微结构，采用电感偶合等离子体光谱仪测定了卵壳中的化学元素．结果表明：白冠长尾雉卵壳的表面晶体层、栅栏锥体层和壳膜层的厚度分别为20．8，220．8和62．5μm，分别占卵壳总厚度的6．8％，72．6％和20．6％；栅栏层有很多蜂窝小孔，其直径为（0．32±0．08）μm（n=30）；卵壳表面有许多圆形或椭圆形的气孔，可能与胚胎发育过程中的气体交换有关，气孔横断面呈细漏斗状，在其上半部有颗粒状填充物．同时比较了白冠长尾雉野生和笼养个体未孵化卵壳中21种化学元素的含量，发现在组成卵壳的化学元素中，野生白冠长尾雉的Ca，Mg，P，S的质量分数叫〉1mg·g，其中Ca含量超过卵壳元素总含量的40％；Na，Si，S，K和A1次之，w=0．1～1mg·g^-1；Fe，Zn，Pb，Mn，Cu，V，Ti元素的w=1～100μg·g^-1；Ni，Cr，Co，Se，Cd的含量最低，w〈1μg·g^-1．与野生个体的卵壳相比，保护区人工饲养的白冠长尾雉的卵壳成分有显著差异，其中S，Cu，Fe，Al，Mn，Si，Sr，Se，Cr等元素野生个体与笼养个体相比，同种元素在不同个体上w的差异均达到20％以上．饲养个体对Fe，Mn，Si和Sr等4种元素摄入明显不足，而S，Cu，Al，Se，Cr等元素则显著偏高，这可能是造成董寨自然保护区白冠长尾雉卵受精率较低的主要原因．建议适当调整饲料中这些元素的配比，以保证饲养条件下白冠长尾雉拥有良好的营养供给，从而提高人工繁殖的成功率．

The eggshell of Reeve＇s Pheasant （Syrmaticus reevesii ） collected from Dongzhai National Nature Reserve in Henan Province, China is studied. By using scanning electron microscopy and inductively couple plasma spectrometry （ICP）, the ultrastructure and elemental composition of the eggshell of Reeve＇s Pheasant are studied. It shows that the average thickness of the surface layer of crystals, the palisade and cone layer and the eggshell membrane are 20. 8, 220. 8 and 62. 5μm, respectively, which accounting for 6. 8%, 72. 6% and 20. 6% of the total thickness of the eggshell. There are many vesicular holes in palisade layer with an average diameter of （0. 32±0. 08）μm（n= 30）. The function of such holes may be of significant to air exchange. The shape of eggshell pore on the surface layer of crystals is round or ellipsis. The fracture surface of the pore is funnel-shaped. Some granules are filled in the upper part of the eggshell pore. The content of 21 elements in the eggshell of wild Reece＇s Pheasant and captive individuals is compared and presented. It indicates that among the elements which composed of the eggshell in the wild, the content of Ca, Mg, P and S is extreme high, w〉1mg·g^-1. The w（Ca） is higher than 40% of eggshell. The content of Na,Si,Sr,K and Al is w=0. 1 - 1mg·g^-1, while Fe, Zn, Pb, Mn, Cu, V and Ti have lower concentrations, w=l - 100μg·g^-1 The w of Ni, Cr, Co, Se, Cd is lower than 1μg·g^-1 The elemental composition in the eggshell of the captive Reeve＇s Pheasant which kept in Dongzhai National Natural Reserve is different obviously from that of the wild, with a difference over 20% on S, Cu, Fe, A1, Mn, Si, Sr, Se and Cr. The less intake of Fe, Mn, Si and Sr in the one hand and overload of S, Cu, A1 and Cr on the other hand may responsible for the low fertility of captive Reeve＇s Pheasants in Dongzhai National Nature Reserve. In order to ensure the Reeve＇s Pheasant in good nutrient condition and to improve the breeding success, the elemental composition in the food shoud be adjusted.