||Assuit Univ. J. of Zoology
||Soliman, F.E.; Moustafa, A.Y., Ismail, T.G. and El-Masry, S.M.
Three pleurobranch species; Berthellina citrina (Ruppel and Leuckart, 1828),
Pleurobranchus grandis (Pease, 1868) and Pleurobranchus albiguttatus (Bergh, 1905)
were collected from seven sites in the upper intertidal zone, on the North Western
Coast of the Red Sea; Egypt. They inhabit the lower surfaces of medium sized stones
in pools containing water all the time.
A redescrpition of Berthellina citrina was carried out and the main recorded new
criteria were: the color variation within the individuals, the structure of the shell, gill,
jaws and radula. Also, Pleurobranchus grandis characterized by having large sized
individuals. The anterior part of the mantle divided into two lobes that overlap with
each other and its dorsum has reddish brown and white polygons arranged in special
manner. As for P. albiguttatus; it has triangular white marks or patches inside
randomly scattered brown tubercles. The tips of the white triangular patches are
directed towards the mantle edge. In addition to these taxonomic criteria some
ecological information as the temporal and spatial distribution of the three species
have been evaluated.