Reproduction and feeding of the sea star Asterina fimbriata in Patagonia, Argentina

ARIANA ALARCÓN SAAVEDRA; GREGORIO BIGATTI; MARTÍN I. BROGGER

Conferencia; International Conference for Young Marine Researchers (ICYMARE); 2021

Sea stars (Asteroidea) inhabit from intertidal zones to greater depths. They can reproduce both sexual and asexually, and exhibit many reproductive strategies. Some species present direct development and their youngs are brood, an interesting uncommon reproductive mode, as a derived reproductive strategy. Asteroidea represents worldwide the most diverse class of echinoderm and is the most representative in Argentine waters. At present, the information about the biology and ecology of some sea stars is practically unknown. The present project aims to study the reproduction and feeding of Asterina fimbriata, a small brooding species that spans along the Patagonian coasts. Samples will be taken monthly during two years at Camarones Bay (44°S-65°W). In preliminary samplings we have observed some individuals of A. fimbriata with an arched body posture, while brooding embryos masses on its oral surface. Whether those individuals are females or if they are not able to ingest food during the brooding period (as occurs in Anasterias minuta, another sea star of this region) it’s uncertain. To unveil this, we will study the existence of a reproductive cycle and its relation with different environmental variables. We will also analyze the developmental stages of its offspring. We will determine the reproductive effort and the relationship between fecundity and parent size, and also describe their diet through a stable isotope and e-DNA metabarcoding techniques. We will evaluate the feeding behavior of adults and the possible influences of water temperature. Furthermore, we will estimate the energetic cost of the adult females throughout the reproductive cycle and estimate the ecological role of this species in the environment. This project will provide new knowledge about the biology of this species, expanding the information to promote the conservation of invertebrate biodiversity in the Southwestern Atlantic