The samples of Crustaceans (Malacostraca) were collected in the fresh water, from
different regions of Al-Assi valley (the river, Katenah lake, the reservoirs such as Al-
Zaafaranh, Al-Sindianh and from Al-teen spring), between August 2010 and Augu
st 2011.
The samples were preserved in alcohol (70 %). After accurate inspection of the collected
samples, there were 4 species classified, two species of freshwater belonging to true crabs
were recognized by depending on the masculine organs as following: Potamon potamois
and Potamon setiger from the Potamidae family, one species of shrimps Atyaephyrra
dessmarestii-orintalis from Atyidae family, and only one species of amphipods which was
Grammars lacustris of Gammaridae family.
All examined species were described morphologically, explaining the most important
classified features that distinguish these species presented with clarifying paintings and
with the pictures for these features.
