Resumo

GUTIERREZ-HOYOS, Nohora Efigenia et al. Bioecological aspects of the freshwater oyster Acostaea rivoli (Mollusca, Etheriidae) in the Opia river, Tolima, Colombia. Rev. acad. colomb. cienc. exact. fis. nat. [online]. 2017, vol.41, n.159, pp.192-199. ISSN 0370-3908.  https://doi.org/10.18257/raccefyn.410.

The freshwater oyster (Acostaea rivoli) is an endemic Colombian species that plays an important ecological role in the aquatic ecosystem. The present study was performed in the Opia river basin, in the Tolima department. 18 sampling stations were evaluated during September and October of 2009. In each location quadrants of 1 m2 were distributed in ten longitudinal transects. Additionally, the vertical distribution was evaluated between 1 and 3 m deep. Parallelly, water samples were taken to analyzed 12 physicochemical variables, some of them were evaluated in situ and the others in the laboratory. In order to identify the relationships between the population and the physicochemical variables a principal component analysis and a Spearman correlation were performed. A total of 303 individuals were observed, the greatest density was recorded in the sampling site Lorencito with 6.67 ind/m2 and the lowest (0 ind/m2) was recorded in the sites Puente Doima, Molino el Federal and Quebrada Opia. As regards to the vertical profile, the highest density was registered in the first meter with 29.62 ind/m2 and the lowest in the third meter with just 4.50 ind/m2. In relation to the water parameters,variables such as: alkalinity (r=0.698; p=0.001), hardness (r=0.650; p=0.004), pH (r=0.714; p=0.001), chlorides (r= -0.530; p=0.024), phosphates (r= -0.603; p=0.008), nitrates (r= -0.490; p=0.039) and total coliforms (r= -0.540; p=0.021) were significantly correlated with population’s abundance and distribution. These variables could be related to mineralization processes in the basin, that combined with high values of calcium, high levels of water oxygen and proper habitats would allow this specie to inhabit the study area. © 2017. Acad. Colomb. Cienc. Ex. Fis. Nat.

Palavras-chave : Endemic; Oyster; Tolima; Physicochemical variable.

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