TRANSMISSIBILITY OF A COCCIDIAN PARASITE OF ABALONE, HALIOTIS-SPP

Renal coccidian infections developed in seed red abalone, Haliotis ruf escens, after 5-7 mo of exposure to infective waters at the Fish and G ame Marine Culture Laboratory in Monterey County, California. Similar infections developed in cohort seed abalone after 3 mo of exposure to infective waters in a barrel culture system located in an embayment ne ar Pt. Hueneme, California. In the experimental trials the coccidian w as directly transmitted from red abalone to pinto abalone after 10.5 m o of cohabitation. One hundred percent of the pinto abalone that share d aquaria with infected red abalone had coccidian infections after 17 mo of cohabitation, while no control abalone developed infections with coccidia. No change in the condition of the abalone or mortality resu lted from natural or experimental infections with coccidia.