Combined effects of temperature and salinity on the demographic response of Proales similis (Beauchamp, 1907) and Brachionus plicatilis (Muller, 1786) (Rotifera) to mercury
Por:
Arreguin Rebolledo, Uriel, Nandini, S., Escobar Sanchez, Ofelia, Sarma, S. S. S.
Publicada:
1 jul 2018
Resumen:
The demographic response of the brackish-water rotifers Proales similis
and Brachionus plicatilis to mercury (0.5, 2, 8 and 32 mu g L-1 of
HgCl2) at different salinity levels (10 and 20 parts per thousand) and
two temperature (25 degrees C and 32 degrees C) regimes were evaluated.
Median lethal concentration (LC50) for P. similis and B. plicatilis was
10 and 16 mu g L-1, respectively, showing that Proales similis was more
sensitive to mercury than B. plicatilis. The rate of population increase
(r) for both species was greater at 10 parts per thousand salinity and
32 degrees C (ranged from 0.6 to 0.95 d(-1)). The r-value decreased as
the concentration of mercury in the medium increased. Regardless of the
temperature, at lower salinity and higher mercury concentration (32 mu g
L-1), P. similis died within six days. The survivorship of P. similis
and B. plicatilis was higher at 25 degrees C than at 32 degrees C
(ranged from 5 to 8 and 7-13 d, respectively). Fecundity was higher at
32 degrees C than at 25 degrees C for both rotifers species. There was a
significant effect of the interaction among salinity, temperature, and
mercury in both species on the reproductive variables such as net and
gross reproductive rates, generation time and the rate of population
increase. Considering the sensitivity of P. similis, we suggest that
this species be included in the list of marine bioassay organisms. (C)
2018 Elsevier Ltd. All rights reserved.
Filiaciones:
Arreguin Rebolledo, Uriel:
Univ Autonoma Sinaloa, Ciencias Recursos Acuat, Fac Ciencias Mar, Mazatlan 82000, Mexico
Nandini, S.:
Univ Nacl Autonoma Mexico, FES Iztacala, Lab Zool Acuat, Edificio UMF, Tlalnepantla 54090, Mexico
Escobar Sanchez, Ofelia:
CONACYT Direcc Catedras CONACYT, Mazatlan 82000, Mexico
Univ Autonoma Sinaloa, Fac Ciencias Mar, Mazatlan 82000, Mexico
Sarma, S. S. S.:
Univ Nacl Autonoma Mexico, FES Iztacala, Lab Zool Acuat, Edificio UMF, Tlalnepantla 54090, Mexico
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