Insights into the rocky shore intertidal microturbellarians of Northern Patagonia

BULNES, VERÓNICA N.; ADAMI, MARIANA L.

Sao Paolo

Simposio; XV International Symposium on Flatworm Biology; 2023

Universidade de São Paulo

The dynamics and composition of intertidal meiofaunal communities, particularly microturbellarians have been scarcely explored in the South-Western Atlantic compared with other regions in the northern hemisphere. Our aim was to explore the biodiversity of free living microturbelarians (sensu lato) inhabiting the intertidal shore located within the San Matías Gulf (40°49′00″ S, 64°43′00″ W), in the Argentinean Patagonia. This Gulf is located in the transitional zone between two zoogeographical provinces in the South-Western Atlantic shores: The Argentine and the Magellanic Biogeographic Provinces. In our study we selected four different intertidal substrates: 1-mussels bed on the rocky platform, 2-sandy patches, 3-tidal pools, and 4-tidal channels. During a five-day bioprospecting trip in the early autumn 2023 (mid-March), we extracted 40 samples. For the extraction, we used 25 cm3 corers in the sandy patches, tidal pools and channels, while in the mussel beds the samples were taken aiming at the centroid of patches with 100% mussel cover. The separation and examination of the samples were carried out in the CIMAS (Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni). For the separation, we used two different extraction methods: decantation of narcotized fauna (MgC1-method) and sea-water ice method (Uhlig). Examination of specimens were carried out with light microscopy, provided with a digital camera. The collected animals were prepared for further microanatomical, histochemical and molecular studies. The preliminary results revealed the presence of two Acoela species, four Macrostomorpha, four Rhabdocoela and three Proseriata. These preliminary results provide the basic information for us to continue exploring this area in a longer and more extensive bioprospection, aiming to assess the meiobenthic community in view of the imminent construction of an oil pipeline in the study area.