Population dynamics of Oithona hebes (Copepoda: Cyclopoida) in a coastal estuarine lagoon of Venezuela: a stage-dependent matrix growth model

We study some aspects of the development and population dynamics of the copepod Oithona hebes. In this experiment, the number of individuals of different stages are monitored through 14 days. The data suggests the absence of density-dependence. A stage-dependent matrix model that predicts the number of the three stages, nauplii, copepodids, and adults, is constructed. Using experimental data we estimate the elements of the matrix model, by using regression as well as maximum likelihood methods. Finally the value of the asymptotic growth rate of the population is obtained with the eigenvalue with largest modulus of the transition matrix. We also estimate a confidence interval of the growth rate, which indicates that its difference from 1 is not statistically significant. The ecological and evolutionary implications of this finding are discussed. The predictions of a stochastic version of the model generally agree with the values experimentally obtained.