Goharia obscura NOV. GEN., NOV. SP. (archoophora : goharidae NOV. FAM.)‎ : a new acoelan turbellaria from the Red Sea

الملخص EN

Eight specimens of a new Acoelan Turbellaria, Goharia obscura novo gen, novo sp.

which belongs to a new family "GOHARIDAE", were collected from a depth of about 50 cm inthe sandy lagoon at Ghardaqa and north leddah in the Red Sea in 1986.

The worm is dark brown with fine white longitudinal strands.

Symbiotic algae and eyes are totally missing.

It has a zeppelin shape.

Reconstructions of the new Acoelan Turbellaria were drawn from the medi~n sagittal position, by the examination of transverse, longitudinal and frontal sections of the worm stained by Mallory stain which gave excellent results..

Camera lucida was also used.

This worm is related to a new family GOHARIDAE because it has a peculiar sense organ, situated near the anterior end, with a ventral aperture.

The mouth is ventral and the pharynx is missing.

The female genital aperture and the Antrum femininum are absent.

The male genital aperture is located dorsally very near to the postel:i°r end.

It is belonging to a new genus, due to the fact that it has from 4 to x cuticularized bursa mouth pieces.

The number of the sperm balls are variable.

The penis is cuticularized.

The main retractor muscles of the sense organ pass through the brain mass, and ends before the statocyst.

It is a new species, as it possesses a highly developed nervous system, consisting of a spherical submuscular nerve plexus, having 5 nerve stems and medio-dorsoventral nerve commissure.