Nutritional and reproductive strategies in a chemosymbiotic bivalve living in a tropical intertidal seagrass bed

Marine Ecology Progress Series

Matthijs van der Geest¹  Reindert W. Nauta¹  Theunis Piersma¹  Sidi Ould Ely¹  Jan. A. van Gils¹  Amadou Abderahmane Sall¹ 

关键词: Bivalvia;    Mixotrophy;    Stable isotopes;    Seasonality;    Reproductive cycle;    Life history;    Sulphide;    Seagrass;   

DOI  :  10.3354/meps10702

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Sulphide-oxidizing endosymbiont-bearing bivalves often dominate the infauna of seagrass-covered sediments, where they control sulphide levels and contribute to carbon cycling by feeding on chemosynthetically fixed carbon and suspended particulate organic matter (SPOM). Previous studies from temperate habitats suggest that SPOM availability may regulate growth and reproduction, since SPOM may be of greater nutritional value than the material provided by bacterial endosymbionts. To examine if changes in diet correlate with body condition and reproductive activity, we studied seasonal patterns in somatic and gonadal investment and gametogenic development in relation to nutrition in the endosymbiont-bearing bivalve Loripes lucinalis in seagrass-covered intertidal flats at a tropical study site (Banc d’Arguin, Mauritania). Carbon stable isotope analysis revealed clear seasonal cycles in the relative heterotrophic contribution to the diet of Loripes, with mean monthly values ranging from 21% in March to 39% in September. Seasonality was also observed for size-corrected body and somatic mass, both increasing from March to October, suggesting food limitation during winter. In contrast, Loripes exhibits a semi-annual reproductive cycle characterized by major spawning events during both January-February and July-August. Growth and gametogenic development seem to especially require supplemental heterotrophic nutrition from June to January. Thus, the ability to shift to heterotrophic feeding contributes to growth, reproductive output and survival in Loripes, with downstream effects on population dynamics and seagrass functioning.

【 授权许可】

Unknown