隆线溞及大型溞头胸甲及孵育囊上皮的构造

The Epithelium Structure of the Carapace and Brood Chember in Daphnia carinata and Daphnia maqna

本文报道了两种枝角类的头胸甲及孵育囊上皮的构造。经文献检索，是首次报道。上皮呈多角形，上皮以突起的角相接，构成了很多孔隙，这些孔隙就是血淋巴腔。背缘及腹缘的血腔都很宽大。上皮细胞的外侧是角质膜，外角质膜很厚，有多层，内角质膜极薄，且有很多微孔。透射电镜观察到成体内侧上皮有微毛及褶突，有输送血淋巴内营养物质及排除废物的功能。外侧上皮未发现特殊的构造。上皮内具特殊的胞器，线粒体能分生小线粒体、分层的球状体，还有具鳞片的分泌细胞，它们都产自外侧上皮。血腔内发现一种有核的变形细胞。内外上皮细胞间有纵横肌纤维，它们的伸缩可能与血淋巴循环有关。

Light microscope and Eletron microscope show that the poyangle internal and external epithelial cells, each linking other, form the hemolymph space in Daphnia carinata and Daphnia magna. The hemolymph space in ventral edge and dorsal side are larger then others. The external cuticle of carapace is thicker and closer then the internal, which can protect the animals. The internal epithelium of bed chamber in adults of D. magna form a lot of microvilli and folds, which generally act as secretion and absorption. There are no these structures in juveniles. It was also found that muscle fiber embed between the epithelium. The contraction of muscle fiber may led the hemolyph to circulate. Three special organelles in epithelial cells were found. Two were giant modify mitochondria and other was secretion organelle whach can secret triangle scales. The research results suggest that the epithelium of brood chamber may provide some materials to the eggs or embryos for their development, as well as that the carapace mainly function as protection.