Individual growth model for the appendicularian Oikopleura dioica

Abstract

A model of individual growth simulating the development of the main compartments and processes involved in the ecophysiology of the appendicularian Oikopleura dioica is presented. O. dioica is one of the 5 most frequent larvacean species inhabiting European seas, and laboratory studies are available for comparison with model outputs. Individual growth and interactions with the external medium are described by state variables and fluxes of C and N, using the stoichiometric approach. Three forcing variables control the animal's growth: temperature, food quantity, and food quality (i.e. C:N ratio and size of particles). Model outputs are compared to experimental data to analyse (1) the effect of food quantity and quality on trunk length; (2) the influence of temperature on trunk length, generation time, respiration, excretion and house production rate; (3) the variability of the filtration rate under different conditions of temperature, food quantity and food quality. Results of the model are coherent with most observations, and validation of the model was successful.