بررسي پراكنش و فراواني زيوپلانكتونهاي خورباهوكلات

Zooplankton abundance and distribution in Bahoo - Kalat estuary at southeast of Iran

The abundance and distribution of zooplanktons with plankton net of 55 pm mesh size were studied in 8 stations of Bohoo-Kalat estuary at southeast of Iran from ovember 1996 to decernber 1997. The main zooplanktons of the estuary were copepoda (87%), protozoa (7.9%), polychaete larvae (1.3%) and barnacle larvae (1.2%). The monthly abundance of copepods were up to 80% and then the dominant zooplanktons. Observed copepod orders were cyclopoida (90.1%), calanoida (8.9%), harpacticoide (=1%) and poecilostomatoida (0.002%). Protozoa consisted of different tintinnids also the genus helicostomella (97.3%)and foraminiferans (1.7%). Larvae of penaeid shrimps, as important zooplanktons, observed during february to april and also in September. The mean yearly density of zooplanktons was 687371 ±266228 (n/mS). The minimal and maximal monthly density was sequencely observed in January and July. Besides the mean of total frequency of zooplankton, mean frequency of copepoda, polychaeta and barnacle larvae at July, and the medusa of coelenterata in april, were significantly different from other months by HSD Tukey test. There was not any significant difference between monthly mean frequencies of other zooplanktones. The minimal and maximal density was observed sequencely at stations 3 and 8. Yearly density of zooplanktonic groups in the stations were not significantly different. Cluster analysis of the density of different zooplanktons in sampling months classed July in a different class from the other months. This analysis detected that the station 8 was different from other stations.