DIFFERENTIATIONS OF TWO SPECIES IN THE FAMILY ERGASILIDAE EXPRESSED BY ULTRASTRUCTURE
新鳋属两个种的分化在超微结构上的表达

The present paper deals with two specie belonging to parasitic copepoda of the family Ergasilidae. Two species of Ncocrqasilus have been observed for the first time by the scanning electron microscopy. It is discovered that the ultrastructure ct swimming legs ard the morphology of thorax-plate are different from each other: hg 1 txopod firt agmnt our spine, bilorked in N. longispinosus, comb-like in X. japonicus; leg 2 and 3 endopod third segment spine, dichela-like in N. lonegispinosus, monoramose in N.. japonicus; leg 2 to leg 4 exopod first segment outer spint, long in N. longispinosus, short in N. japonicus. These differences stated above are called the expression of differentiation between two species and those differences in whole biological kingdom are called the expression of biodiversity.