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Seasonal variation of the community of copepods in the eastern sector of the Gulf of Cariaco, Sucre state, Venezuela

Abstract:

Copepods are the most numerous group of zooplankton in tropical coastal systems; they are mainly affected by salinity gradients, as occurs in the eastern sector of the Gulf of Cariaco. This study purposed to study the temporal and spatial variations in the structure of the copepod community during June, July, August, and September 2009 (rainy season) and October, November, and December 2009 and January 2010 (dry season). Samples were collected with a standard 60 cm diameter zooplankton net with a 330 µm mesh at the surface level. Temperature, salinity, and dissolved oxygen were taken in situ with a multi-parameter probe (YSI). Salinity presented a marked monthly variability, with values between 32.5 ± 1.56 and 38.5 ± 0.25 UPS in the rainy and dry seasons, respectively. A total of 45 copepod taxa were identified and Acartia tonsa was the most representative species throughout the study, followed by Temora turbinata, Paracalanus quasimodo, Subeucalanus subcrassus and S. subtenuis. The present study did not show a clear seasonal pattern in the abundance, diversity, and uniformity of the copepod community and the salinity values; therefore, it can be considered spatially uniform and seasonally homogeneous concerning these parameters.