Demographic responses of Cladocerans (Cladocera) in relation to different concentrations of humic substances
Por:
Gama Flores, Jose Luis, Salas M.E.H., Sarma S.S.S., Nandini, S.
Publicada:
10 nov 2019
Ahead of Print:
1 ago 2019
Resumen:
Cladocerans are constantly exposed to humic substances in nature, yet
the effects of these substances on their survival and reproduction are
not well known. Here, the effects of humic substances (20 and 40 mg L-1)
(HS) on the life history variables of three common cladocerans,
Ceriodaphnia dubia, Moina macrocopa, and Daphnia pulex were evaluated.
The results showed that the effect of humic substances on the tested
cladocerans is species-specific, affecting either survival, reproduction
or both. For M. macrocopa, exposed to HS at a concentration of 40 mg
L-1, the average lifespan and the life expectancy at birth were
significantly reduced as compared to controls, but for C. dubia and D.
pulex these parameters were increased. Gross reproductive rate was
unaffected by the HS level for both D. pulex and M. macrocopa, but it
was significantly higher for C. dubia. When compared to the
corresponding controls, for HS-exposed cladocerans, the rate of
population increase was significantly reduced in case of D. pulex while
it was stimulated for both C. dubia and M. macrocopa. It appears that
humic substances had a slightly stronger influence on survivorship than
on reproduction of the tested cladocerans.
Filiaciones:
Gama Flores, Jose Luis:
Carrera de Biología, Universidad Nacional Autónoma de México, FES Iztacala, Tlalnepantla, Edo. de Méx, Mexico
Salas M.E.H.:
Carrera de Biología, Universidad Nacional Autónoma de México, FES Iztacala, Tlalnepantla, Edo. de Méx, Mexico
Sarma S.S.S.:
División de Investigación y Posgrado, Universidad Nacional Autónoma de México, FES Iztacala, Tlalnepantla, Edo. de Méx, Mexico
Nandini, S.:
División de Investigación y Posgrado, Universidad Nacional Autónoma de México, FES Iztacala, Tlalnepantla, Edo. de Méx, Mexico
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