Study of Morphology and Density variation of Aequoreidae and Dipleurosomatidae (Cnidaria: Hydromedusae: Conica) in Bahrakan Coasts (North Western Persian Gulf)

This study was done on Hydromedusae in Bahrakan coasts due to identification and calculated of Hydromedusae density. Zooplankton samples collected by plankton net (300μm) from six stations in July, August, October of 2010 and December, February, April of 2011. Environmental parameters such as salinity, pH, temperature and dissolved oxygen were measured. In this study 6 species were identified. Aequorea forskalea, Aequorea sp., Dipleurosoma sp.1, Dipleurosoma sp.2 and Cuvieria sp. are the first report in the Iranian waters of the Persian Gulf. The medusae density was the highest in July (60.97 ± 2.56 N/10m3) and lowest in August (2.01 ± 0.76 N/10m3). The result of Correlation showed that the distribution of medusaes has more correlated with temperature (P<0.01).