Population growth responses of three Brachionus species (Rotifera: Brachionidae) fed live and dead (frozen or heat-killed) alga (Chlorella vulgaris)
Por:
Sarma S.S.S., Espinosa-Rodriguez C.A., Nandini S.
Publicada:
1 ene 2007
Resumen:
We evaluated the population growth responses of three species of Brachionus (B. angularis, B. havanaensis and B. rubens on Chlorella vulgaris at three densities (0.0625x106, 0.125x106 and 0.25x106 cells mL-1) offered in three forms (live, frozen and heat-killed). When raised on live Chlorella, increase in algal concentration resulted in increased population abundances of all the three brachionid rotifers. For B. angularis and B. rubens at any given food density live Chlorella resulted in higher population densities than when fed in frozen or heat-killed form. However, for B. havanaensis, heat-killed alga supported higher population densities than on live or frozen Chlorella. B. havanaensis failed to grow on frozen alga regardless of the food density, while the other two rotifers showed positive growth, especially under higher diet levels. The rate of population increase (r) varied from 0.45±0.03 to -0.58±0.01 per day, depending on the brachionid species, algal density and the diet form. Statistically, the r of B. angularis and B. havanaensis was significantly (p <0.05) affected by algal form and the density as well as their interaction. However, the r of B. rubens was not significantly affected by the algal form (p>0.05), although algal concentration and its interaction with diet type were significant (p<0.001). Thus, our study showed that the response of tested species Brachionus varied depending not only on the form in which Chlorella was offered but also on its concentration. © International Scientific Publications, New Delhi.
Filiaciones:
Sarma S.S.S.:
Laboratorio de Zoología Acuática, Divisio de Investigación y Posgrado, Universidad Nacional Autónoma de México, Edificio UMF, Campus Iztacala, 54090 Tlalnepantla Edo. de México, Mexico
Espinosa-Rodriguez C.A.:
Laboratorio de Zoología Acuática, Divisio de Investigación y Posgrado, Universidad Nacional Autónoma de México, Edificio UMF, Campus Iztacala, 54090 Tlalnepantla Edo. de México, Mexico
Nandini S.:
Divisio de Investigación y Posgrado, UIICSE, Universidad Nacional Autónoma de México, Campus Iztacala, 54090 Tlalnepantla Edo. de México, Mexico
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