Temperature-dependent demographic differences in sessile rotifers of the genus Limnias (Rotifera: Gnesiotrocha)
Por:
Jimenez-Santos, M. A., Sarma, S. S. S., Nandini, S.
Publicada:
1 jul 2019
Resumen:
Aim : Rotifer research on sessile taxa has received less attention
because they are not easy to identify in fixed samples. In the Lake
Xochimilco, a Ramsar site in Mexico City, three morphotypes of L.
ceratophylli and a single morphotype of L. cf. melicerta occur in
different densities. The aim of this study was to test if temperature
was responsible for the differences in the population densities of these
morphotypes.
Methodology : The presentstudy was carried out using population growth
method consisting of 4 treatments (3 morphotypes of L. ceratophylli and
one of L. cf. melicerta) at 20 and 25 degrees C. Experiments were
carried out in 50 ml glass jars containing 25 ml synthetic medium with
Chlorella vulgar's as food. The population growth rates (r) were
derived. Analysis of variance (ANOVA) and post hoc tests were used to
quantify the intro -and interspecific differences in the population
growth rates.
Results : The temperature levels for optimal population growth rates
differed among the morphotypes of same species. At 20 degrees C, the
morphotype 1 had the highest r (0.23 d(-1)) similar to that of L. cf.
melicerta, while morphotype 3 had the lowest (0.15 d(-1)). For L. cf.
melicerta, the r was higher at 25 C than at 20 degrees C. Of three
morphotypes of L. ceratophylli, morphotype 3 had the highest rat 25
degrees C similar to that of L. cf. melicerta at same temperature.
Interpretation : There were significant differences among growth
patterns within the morphotypes of L. ceratophylli, depending on culture
temperature. These trends highlight the relative importance of
environmental variables in differentiating morphotypes of a sessile
species complex which could explain their possible seasonal. changes in
the natural waterbodies.
Filiaciones:
Jimenez-Santos, M. A.:
Univ Nacl Autonoma Mexico, Posgrad Ciencias Mar & Limnol, Mexico City 04510, DF, Mexico
Sarma, S. S. S.:
Univ Nacl Autonoma Mexico, Lab Aquat Zool, Tlalnepantla 54090, Mexico
Nandini, S.:
Univ Nacl Autonoma Mexico, Lab Aquat Zool, Tlalnepantla 54090, Mexico
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