THE PEOPLE FROM THE LARBIM
Researchers and Fellows
Lic. Ariana B. Alarcón Saavedra
Doctoral Fellow CONICET
My research is focused in the integral study of reproductive strategy and trophic ecology of a small brooding species sea star Asterina fimbriata along the Patagonian coasts, to understand life history and estimate the ecological role of this species in the environment. This study will provide new knowledge about the biology of this species, expanding the information to promote the conservation of invertebrate biodiversity in Patagonia.
- To study the reproductive cycle of sea star Asterina fimbriata and its relation with different environmental variables.
- Analyze the development stages, number and size of its offspring.
- Determinate reproductive effort of the adult females and analyze relationship between fecundity and parent size.
- Determinate the diet composition along study period through a stable isotope and e-DNA metabarcoding techniques. Also study feeding behavior of adults and the possible influences of water temperature.
- Estimate energetic cost of the adult females throughout the reproductive cycle and evaluate the ecological role of this species in the environment.
Sea stars are very important in the marine ecosystems and the most representative class of echinoderms in Argentine waters. At present, the information about biology and ecology of some sea stars is practically unknown. There are species that have developed an interesting uncommon reproductive mode as a derived reproductive strategy by which they brood their embryos and take care of their young during development. This phenomenon is characteristic in species of high and medium latitude, and in species that live in deep environments.
A lot of starfish feed by the eversion of their stomach incorporating partially digested prey. Traditionally, the studies of feeding have been done directly from digested material, but this difficult to identify the remains. Due to this, in recent years indirect methods have been started to complement the traditional technique such us stable isotope and e-DNA metabarcoding techniques. The e-DNA metabarcoding allows to obtain better results of the taxonomic composition of diet from highly digested remains and allows to sample a lot of much environmental substrates for obtain information.
Asterina fimbriata is a small brooding species of 20 mm approximately, that spans along the Patagonian coasts. At present, the information about biology of this sea star is practically unknown. 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. Is very important to know the population, reproductive and feeding parameters of this species to provide information that help to conserve of invertebrate biodiversity in Patagonia.
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