Morphofunctional bases of feeding and the trophic role of Lychnorhiza lucerna (Scyphozoa, Rhizostomeae)

Abstract

Over the last two decades, considerable attention has turned to scyphomedusae ecology due to the apparent increase in certain populations. Their feeding rates are high and they can deplete planktonic populations causing drastic consequences for the economy and the ecosystem. Data about feeding habits of medusae of Rhizostomeae, which dominate in tropical and subtropical coastal environments, are scarce. In Brazil, Lychnorhiza Lucerna Haeckel, 1880 is the most abundant Rhizostomeae and also reaches high densities during their population peaks, but nothing is known about feeding habits. This project aims to: (i) to describe the morphology and functionality of structures prey capture of L. Lucerna, (ii) to describe the species diet, prey selectivity and individual feed rates and (iii) to determine the species trophic level and the main nutritional sources by means of stable isotope analysis. Thus, the ecological role of these species will be better understood and essential information, to predict the consequences of the species blooms will be generated.