Morphology of a new species of water mites Linobia porosa (Astigmata, Linobiidae) collected from roots of floating plant, Eichhornia crassipes

The adult specimens of the water mite Linobia porosa were collected from the roots of the floating aquatic plant Eichhornia crassipes in the Nile River, Sohag Governorate, Egypt. The morphological characters of the present species align with those of the family Linobiidae and the genus Linobia. The specific characters of the present species were compared with those of other published species of the same genus. These characters are summarized as follows: The body is broadly oval-shaped with a triangular rostral shield. The fixed digit of each chelicera bears three serrated setae and two simple setae behind its movable digit. The palpal tarsus is inverted trapezoidal in shape and carries ten setae and five solenidia of varying sizes. The propodosomal region bears a long simple sensory seta, a pair of serrated setae, and three exobothridial setae. The hysterosomal region is adorned with raised circular warts and consists of seven plates (five central, one lateral, and one opisthosomal). The central plates are guarded by a row of circular pores. The lateral plate is inverted U-shaped and bears two pairs of tiny simple setae, while the opisthosomal plate carries a pair of simple setae, a pair of opisthosomal glands, and a group of scattered pores.