||About the interest of a zooplankton compartment in pond systems: methodology to study the growth kinetic of Daphnia pulex on Scenedesmus sp.
LIADY MOUHAMADOU NOUROU DINE ,
TANGOU THIERRY TABOU ,
FIOGBE EMILE DIDIER ,
HENRY MICHEL CAUCHIE ,
VASEL Jean-Luc ,
||Water Science & Technology
||A reliable characterization of cladocerans’ growth kinetic on their substrates is crucial for the
estimation of their biochemical conversion rate in pond models. Although many studies reported
cladocerans’ growth inhibitions by high chlorophyceae contents, their growth kinetics had continued
to be described in many pond system models by Monod-type kinetic, which describes growth
saturation by high substrate contents, but fails to explain the disappearance of cladocerans observed
during chlorophyceae’s bloom periods. This study aimed to develop a methodology and assess
whether growth-inhibition-type models used to describe microbial growth kinetics can be applicable
to cladocerans. Experiments were carried out using Daphnia pulex populations and Scenedesmus sp.
First, biomass of D. pulex was measured through digital image processing (DIP) during growth
experiments. Then, three candidate models (i.e., Andrews, Edward and Haldane models), along with
the Monod model, were fitted to the observed data and compared. The results showed that the DIP
technique provided reliable results for estimating the biomass of D. pulex. Our findings show that the
candidate growth inhibition-type models satisfactorily described D. pulex’s growth kinetic (86%
variance accounted for). Scenesdemus sp. were not strong inhibitors of the growth of D. pulex (high
inhibition constant and low half-saturation constant found).
||cladocerans, growth-kinetic, image processing, modeling, pond
||1436 - 1440