6% of the total zooplankton, with relatively high numbers of Synchaeta okai at stations EPZ015666 1, 3, 4 during summer. The diversity index value (H′) of the zooplankton community ranged between 0.66 and 2.16. The overall mean were 1.82 ± 0.26 (winter), 1.18 ± 0.37 (spring), 1.90 ± 0.15 (summer), 1.90 ± 0.15 (autumn). Diversity index values were generally higher during summer and autumn with parallel lower values of dominance at all stations. Station
1 attained higher values than those of the other stations. Highest density (annual average: 41.6 × 103 ind. m−3) was recorded at station 3, and lowest recorded at stations 6 and 7 (annual averages: 17.3 × 103 and 17.5 × 103 ind. m−3, respectively). Copepods were strongly dominant, making up the bulk of the zooplankton population. The highest copepod densities were observed in stations 6, 7, 5, 10 and 11. Copepod larval stages represented high percentage, fluctuated between 23.9% (station 6) and 65.9% (station 9) with an annual average of 42.1% of the total copepods. Protozoans were the most dominant group at stations 1, 2, 3 and 8, fluctuating between 37.2% (station 1) and 54.8% (station 3). Their abundance decreased to minimal at stations 6 and 7 (12.7% and 11.4%). Schmidingerella spp. were the most dominant fluctuating between 67.4% (station 1) and 96.2% (station 8). Rotifers were
third Pictilisib chemical structure in abundance (4.6%), and showed higher percentage at station 1 (12.0%) and decreased to reach minimal at stations 5 and 8. Cirripeds were relatively abundant in station 1 (10.3%), whereas in the other stations they accounted for only 0.3–2.7% of zooplankton numbers. Larvaceans contributed as little as 1.7% of the total count. The zooplankton standing crop was the smallest during winter (average: 11 ± 10.6 × 103 ind. m−3). The contribution of copepods to the total zooplankton has been represented by 69.5% with an increase of their larval stages (45.8%). Moreover, the dominant adult species was Oithona nana (19.0% of the total zooplankton). Protozoans were the second most abundant group making up 11.0% of the total zooplankton count. They were dominant by Schmidingerella
serrata and Tintinnopsis campanula Ehrenberg, Buspirone HCl 1840, representing respectively, 7.7% and 1.2% of the total zooplankton ( Fig. 3). During this season, cirripedes were represented by nauplii, which contributed 10.7% of the total count. Annelida constituted 6.3% of the total zooplankton with Spionid and Trochophore larvae were the dominant. In spring, the zooplankton crop was larger than other seasons (average: 31.3 ± 21.5 × 103 ind. m−3). It was the most productive season for protozoans, representing 78.2% of the total zooplankton. They were represented by 22 species (1 non tintinnid ciliates, 16 tintinnids and 5 foraminiferans) with the dominance of Schmidingerella serrata (73.9% of the total zooplankton). Copepods were the second dominant group, accounting for 17.6% of the total count.