| dc.description.abstract | Demographic responses of a commensal
annelid of freshwater crayfish, Stratiodrilus aeglaphilus,
to a sublethal organic enrichment were tested.
Censuses of the S. aeglaphilus population were
performed every 3 days during a 27 days period.
The demographic variables were estimated using a
quadratic programming method. Population growth
rate (k) was 1.0230 in the control, and 0.9145 in the
organic enrichment treatment, it was indicating
positive growing and decrease, respectively. Decomposition
analysis showed an antagonistic response of
the demographic parameters to organic enrichment,
with negative contributions from eggs and juveniles
stasis and growing probabilities, and positive contributions
from adults survival and fecundity. After the
organic enrichment, the positive effect on adults
could not compensate the adverse effect on the early
stages, thus causing a reduction of the population
density of S. aeglaphilus. | |
