Abstract

CELIS, SEBASTIÁN; MANCERA, ERNESTO  and  LEON, JENNY A.. Assessment Of The Pajarales Complex Rotiferofauna During The Rainy Season, Departamento De Magdalena, Colombia. Acta biol.Colomb. [online]. 2008, vol.13, n.2, pp.23-40. ISSN 0120-548X.

ABSTRACT In order to assess the potential effects of the Magdalena River recommunication with its former delta, we studied the abundance and composition of the rotiferofauna of the Pajarales Complex (PC) during its highest annual zooplankton abundance. We selected the Rotifera phylum, due to its high reproductive rates and the efficiency in energetic transformation process. We sampled the rotifers with a van Dorn bottle, during the second rainy season in 2006. During each sampling we registered salinity, temperature, pH, and dissolved oxygen. We calculated the rotifer diversity using the Shannon-Wiener H’ (log10) index comparing among sampling sites and sampling dates to establish variations along the study period. The physico-chemical variables were graphically related with the diversity values calculated using 0,05 for α and 95% for the confidence interval. We found a total of 20 morphotypes belonged to Brachionidae, Lecanidae, Filiniidae, Synchaetidae, Hexarthriidae and Testudinellidae families, been Brachionidae and Lecanidae the most abundant. The relationships between diversity and physico-chemical variables, show salinity as the main responsible of the rotifer diversity. In conclusion, the current rotiferofauna in the PC is most abundant and diverse than 16 years ago, before the recommunication with the Magdalena River. Likewise, dissolved oxygen concentration, pH and salinity of the CP waters were different. Taking into account that salinity was the most influent factor in the rotiferofauna diversity, the river recomommunication probably favored the increment of rotiferofauna diversity in the PC.

Keywords : Rotíferofauna; Pajarales Complex; Magdalena River; Ecological Rehabilitations; Colombian Caribbean.

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