Seuil de production de pseudo-fécès de l'huître creuse du Pacifique : Crassostrea gigas (Thunberg) dans des conditions de faibles charges particulaires

This study is part of a comprehensive research program focusing on the oyster shellfish management in the Marennes-Oleron Bay: Within this program, a task aimed to develop a biological model of the Pacific cupped oyster Crassostrea gigas. Our study addressed the issue of pseudo-faeces production threshold under various diet quality levels. Pseudo-faeces sampling was carried out using particulate matter concentration below Il mg 1-1 The various modalities prompted us to define two pseudo-faeces production models. The first model was developed using natural seawater. The organic matter ratio ranged from 25 to 45% while the pseudo-faeces production threshold reached 2.9 to 4.4 mg 1-1 of total particulate matter. The second model was established using seawater conditions enriched with algal culture. Within the range of 40 to 80 % of organic matter, the pseudo-faeces production threshold varied from 2.12 to 4.37 mg 1-1of the total particulate matter. The pseudo-faeces production threshold was estimated to 1.0 mg 1-1 of consumed particulate matter.