Dinámica poblacional de Allonais lairdi (Oligochaeta, Naididae) en Los Talas, Provincia de Buenos Aires
The main objective of this work is to analyse the life cycle of Allonais lairdi Naidu, 1965 considering seasonal variations in abundance and biomass, periods of asexual and sexual reproduction, and dispersion. Quantitative samples of the vegetation were taken fortnightly (July 1994-1995) from a lentic water body located in Los Talas, Buenos Aires Province. Physicochemical parameters were measured: depth, transparency, temperature, conductivity, pH, and dissolved oxygen. Allonais lairdi showed a great fluctuation in density due to an asexual reproduction. The highest abundance was registered in February and immediately after individuals sexually mature were found. They represented 1. 63 % of the population. The period of sexual maturity was short, during March. The peak in biomass was registered in the fall, two months after the peak of abundance. This period is considered a generation cycle. Estimated annual production expressed as dry weight was 0.25 g.m-2.Three cohorts were succeeded in the analysed population: the first in October, the second in December (including the mature individuals) and the third one in April. The distribution pattern was analysed by using the Morisita Index. It showed a distribution at random during most of the life cycle being contagious as the density was low.
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| Format: | Digital revista |
| Language: | spa |
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Asociación Argentina de Ecología
1999
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| Online Access: | https://ojs.ecologiaaustral.com.ar/index.php/Ecologia_Austral/article/view/1606 |
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