Microstructure and ultrastructure of Sphaerospora chinensis.

Sphaerospora chinensis has experienced a complicated and confused naming process,but we have corrected this misleading situation in paper.We observed its structure by both light microscopy and electron microscopy.The whole shape of S.chinensis was ovoid and its polar capsules were surrounded by a lucent central layer,and so did the polar filament.Valve cells were originated from valve-forming body,a special tiny structure at the edge of pansporoblast.The two valves were jointed by tight junction in mature individuals.The two valves of spore both had several lines of stripes on the outer surface,but they were different in shape and colour to some extent.S.chinensis showed gill-parasitized and monosporous pansporoblasts.With the development of S.chinensis,organelles such as endoplasmic reticulum and microtubules degenerated or even disappeared.The extrusion of polar filament from polar capsule was a common phenomenon which suggested that the tendency of extrusion was likely due to the way of parasitism,i.e.,the sticky polar filament contributed to making the spore adhere to the gill filament.Chongqing was found to be a new distribution place of this species.