DISTRIBUTION, GROWTH, PRODUCTION, AND ECOLOGICAL SIGNIFICANCE OF THE CLAM UNIO-TERMINALIS IN LAKE KINNERET, ISRAEL

The distribution, body composition, growth rate, and population struct ure of Unio terminalis were measured at different sites of Lake Kinner et (Israel). Maximum clam density was found on the muddy sand between 0.3-6 m depth. Clams were most abundant in the River Jordan inlet zone , where they showed the highest growth rate. This was probably related to both highest food availability and the highest density of fish hos ting Unio glochidia in this area. U. terminalis in Lake Kinneret has a more massive shell and ash content as compared with the European Unio species. The annual P/B ratios of U. terminalis populations at differ ent sites were similar and ranged within 0.17-0.18. The computated fil tration capacity and energetic budget permit the assumption that the U . terminalis population plays a substantial role in removal of organic particles from the water in the Kinneret shallow inshore zone (up to 15 m depth), and in nutrient recycling.