Af. Alva-martinez et al., Comparative population dynamics of three species of cladocera in relation to different levels of Chlorella vulgaris and Microcystis aeruginosa, CRUSTACEANA, 74, 2001, pp. 749-764
We conducted population growth experiments for 22-30 days using three speci
es of cladocerans measuring (adult mean length (Am) standard error): Daphni
a pulex (2413 +/- 129), Moina macrocopa (1286 +/- 49) and Ceriodaphnia dubi
a (951 +/- 57) fed the green alga Chlorella vulgaris and cells separated by
ultrasonic waves of the Cyanobacterium, Microcystis aeruginosa, offered in
three densities (0.75 x 10(6), 1.5 x 10(6), and 3.0 x 10(6) cells ml(-1)).
An increase in the availability of Chlorella and Microcystis resulted in a
n increase in the abundance of D. pulex. The response of the other two spec
ies to Chlorella and Microcystis differed greatly. M. macrocopa showed incr
eased population abundance with increasing Chlorella levels but crashed com
pletely when fed Microcystis on day 2. On the other hand, the population de
nsities of C. dubia showed an inverse relation with Chlorella levels but in
creased with increasing levels of Microcystis aeruginosa. C. dubia reached
a peak density of 37 +/- 1 ind. ml(-1) at 3.0 x 10(6) cells ml(-1) of Micro
cystis. Under the same food conditions, D. pulex reached 10 +/- 0.5 ind, ml
(-1). The rate of population increase per day (r) was similar (0.24) for D.
pulex and M. macrocopa on Chlorella vulgaris at 3.0 x 106 cells ml(-1). No
statistically significant differences were detected for r values and the p
eak population densities between D. pulex fed Chlorella or Microcystis, but
the differences were significant for Moina and Ceriodaphnia. We found no c
lear relation between the body size of cladocerans and their ability to con
sume Microcystis cells, although D. pulex consistently grew well on either
Chlorella or microcystis.