Seasonal Response of Daphnia pulex to Cyanobacterial Extracts at Different Temperatures in Valle de Bravo Reservoir (Mexico)
Por:
Nandini, S., Sanchez-Zamora, Carlos, Sarma, S. S. S.
Publicada:
1 feb 2021
Resumen:
Valle de Bravo reservoir supplies drinking water to 40% of Mexico City.
Here we present data on the population growth and life-table demography
of the cladoceran Daphnia pulex, cultured at temperatures of 20 degrees
C and 25 degrees C and with different concentrations of the crude
extracts from blooms of Microcystis aeruginosa, collected in January,
and Woronichinia naegeliana, collected in September. We hypothesized
that Daphnia pulex would be more sensitive at the higher temperature and
to toxins from W. naegeliana as these blooms have been shown to be more
toxic to rotifers. We extracted the toxins and conducted acute toxicity
tests at eight concentrations of microcystins at 20 degrees C. The LC50
was 26.8 mu g/L and 11.5 mu g/L, respectively, for Microcystis and
Woronichinia samples. The chronic toxicity tests included population
growth and life-table demography studies at 5 and 10% of the LC50
concentration, at 20 degrees C and 25 degrees C. Four replicates for
each of the three treatments, which consisted of treatments with low and
high cyanotoxin levels and a control without cyanotoxins, were set up.
The population growth rate ranged from 0.18 to 0.42 d(-1) on the
extracts from M. aeruginosa (January) and from 0.2 to 0.31 on extracts
from W. naegeliana. Daphnia, being better adapted to cooler
temperatures, was more adversely affected at 25 degrees C than 20
degrees C. The adverse effect of cyanobacterial extracts was greater
from Microcystis than Woronichinia blooms. The tolerance of Daphnia
pulex to cyanotoxins depends on the bloom-forming species and the
temperature.
Filiaciones:
Nandini, S.:
(Corresponding Author), Univ Nacl Autonoma Mexico, Lab Zool Acuat, Div Invest & Posgrad, Campus Iztacala,Ave Barrios 1, Tlalnepantla 54090, Estado De Mexic, Mexico
Univ Nacl Autonoma Mexico, Lab Zool Acuat, Div Invest & Posgrad, Campus Iztacala,Ave Barrios 1, Tlalnepantla 54090, Estado De Mexic, Mexico
Sanchez-Zamora, Carlos:
Univ Nacl Autonoma Mexico, Lab Zool Acuat, Div Invest & Posgrad, Campus Iztacala,Ave Barrios 1, Tlalnepantla 54090, Estado De Mexic, Mexico
Sarma, S. S. S.:
Univ Nacl Autonoma Mexico, Lab Zool Acuat, Div Invest & Posgrad, Campus Iztacala,Ave Barrios 1, Tlalnepantla 54090, Estado De Mexic, Mexico
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