ANA MILSTEIN - Agricultural Research Organization, Fish and Aquaculture Research Station, Dor, Mobile Post Hof Hacarmel 30820, Israel
GIDEON HULATA. - Agricultural Research Organization, Fish and Aquaculture Research Station, Dor, Mobile Post Hof Hacarmel 30820, Israel

Israeli commercial farms data were analyzed through multivariate analyses to study the relationships among fish species grown in a wide range of stocking combinations, culture seasons and management practices in different regions and farms. Data analyzed included 1,124 observations from well managed growout ponds from 31 farms located in four regions. The results of the factor and canonical analyses applied to the dataset show that: a) yield of each species was mainly affected by its own stocking density; b) feed pellets mainly affected common carp with little or no effect on other species; c) tilapia accounted for most of the variability in the polyculture system. Pond size and depth had a relatively low influence on fish production, compared to the abovementioned variables. Some variation among regions, mainly attributed to difkrent climatic conditions, were indicated.