Water inside the shell are benthic animals, specifically the mollusc phylum, the river water in the common species are: China round field snail Flat-bellied round field snail China round field snail Pear-shaped ring-pronged snail Rusty ring-pronged snail Square ring-pronged snail Snail (ear-shaped river snail) Hubei nails snail Threaded swamp snail Ear radish snail Stillwater vertebrate solid snail, etc., if you want to picture, put these names Baidu search pictures on the line, all are common freshwater snail species. Bugs zooplankton; branching horns, commonly known as fish bugs (freshwater: naked abdomen trevally, weevil trevally), copepods (seawater), aquatic insects more : water jumping insects, stoneflies, mayflies, dragonflies larvae, fish lacewings, stoneworms, rocking mosquito larvae a lot of not in detail, the picture of their own Baidu