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¹ National institute oceanography and fisheries, fisheries, Alexandria, Egypt DOI : 10.4194/1303-2712-v19_4_09 Viewed : 3743 - Downloaded : 2735 Assess the state of fish assemblies in surf zone of the Egyptian Mediterranean coast off Alexandria was carried out by determining community parameters such as abundance, diversity and impact of Immigrant fishes on species composition. Fish community in Beach area off Alexandria includes 22 families. Only 9 species dominated the catch representing 81.41% by number and 60.89% by weight. Immigrant fishes in beach area included 10 of 45 species, these migrant species representing about half of the community by number (47.07 %) and 38.34 % by weight. The index of relative dominance (% IRD) revealed that Siganus rivulatus was dominated in Beach area contributing about 54.47% and it represent frist rank by number in all seasons. The results of biological indices lead us to consider fish community in summer more diverse than in others seasons. Relation between fullness index and numerical abundance of dominant fish species showed that, the Maximum values of both indices were found for S. rivulatus and Scomber japonicas in spring and for Stephanolepis hispidus in winter, while Pagellus erythrinus reavealed the maximum fullness index in autumn and and highst numerical abundance in winter. Significant positive correlation was found between abundances of Diplodus vulgaris and Pagellus erythrinus (r = 0.98**), and between Sardinella aurita and Boops boops (r = 0.99**), in contrary, Sardinella aurita revealed significant negative correlation with Stephanolepis hispidus (r = - 0.89*). Ecological impacts of invasive alien species are decline in abundance of endemic species. The dominance of alien species can attributed to their ability to tolerate multiple anthropogenic stressors, in altering communities. Keywords : Ecological guilds, Fish assemblage, Beach area off Alexandria