Freshwater crab Freshwater crab There are around 1,300 species of freshwater crabs, distributed throughout the tropics and subtropics, divided among eight families. They show direct development and maternal care of a small number of offspring, in contrast to marine crabs which release thousands of planktonic larvae. This limits the dispersal abilities of freshwater crabs, so they tend to be endemic to small areas. As a result, a large proportion are threatened with extinction. There are more than 1,300 described species of freshwater crabs, out of a total of 6,700 species of crabs across all environments. The total number of species of freshwater
Forensic limnology water conducting tissues, which affects their dispersion throughout ecosystems. These microscopic organisms mainly inhabit freshwater environments because of their inability to survive with the cleaning agents present in domestic water sources. Diatoms are identifiable based on each species unique silica cell walls and vary depending on their environment. Because they have determinant properties diatoms create flora profiles for scientists. When these microscopic algae die, their frustules (silica cell walls) becomes a part of the water sediment. The presence of the frustules enables scientists to compare the cell walls of the deceased organisms with the living diatoms to determine characteristics of