SCANNING ELECTRON-MICROSCOPY STUDY OF A COPULATING MONORCHIID (TREMATODA, DIGENEA)

During a survey of parasites of fishes from the Kuwaiti coast of the A rabian Gulf, a pair of digeneans were found in copulation in the intes tine of 1 of 4 Gnathodon speciosus; the digeneans were recovered and s tudied by scanning electron microscopy (SEM). SEM micrographs suggest a I-way transfer of sperm and reveal the presence of longitudinal ridg es with openings or depressions in the metratermal segment of the term inal organ of the recipient. The digeneans were identified as monorchi id species of Lasiotocus. This is the first evidence of copulation in a digenean demonstrated by SEM.