Reproduction in deep-sea vent shrimps is influenced by diet, with rhythms apparently unlinked to surface production

Paru dans Ecology and Evolution

Methou, P., Chen, C., Kayama Watanabe, H., Cambon, M-A., Pradillon, F. Variations in offspring production according to feeding strategies or food supply have beenrecognized in many animals from various ecosystems. Despite an unusual trophic structure based on non-photosynthetic primary production, these relationships remain largely under-studied in chemosynthetic ecosystems. Here, we use Rimicaris shrimps as a study case to explore relationships between reproduction, diets, and food supply in these environments. For that, we compared reproductive outputs of three congeneric shrimps differing by their diets. They inhabit vents located under oligotrophic waters of tropical gyres with opposed latitudes, allowing us to also examine the prevalence of phylogenetic vs environmental drivers in their reproductive rhythms. For this, we used both our original data and a compilation of published observations on the presence of ovigerous females covering various seasons over the past 35 years. We report distinct egg production trends between Rimicaris species relying solely on chemosymbiosis-R. exoculata and R. kairei-and one relying on mixotrophy, R. chacei the life history of vent animals.