Background: The aquatic Acari are known as water mites and occupy a wide range of habitats. The freshwater mites, Unionicola aegyptiaca, were collected from the freshwater mussel, Caelatura aegyptiaca, River Nile, Sohag,Egypt. The present paper focuses on the structure of the cuticle and musculature of freshwater mite, U. aegyptiaca.
Results: Histologically, the cuticle consists of two main layers: epicuticle and procuticle. The latter divided into twosublayers, exocuticle (exo) and endocuticle (en). The musculature of the present species, U. aegyptiaca, is dividedinto three regions: gnathosoma, idiosoma, and legs. The muscles of the body are classified according to their position and function.
Conclusion: Details of muscles of gnathosoma, coxal epimerae, genital field, and legs were all described and discussed. The cuticle and musculature of U. aegyptiaca were studied by using the light microscope, and the drawings were down with the help of a camera Lucida. It is likely to note that the cuticle and musculature of freshwater mite, U. aegyptiaca, were described and discussed for the first time in Egypt.