Registro de <i>Cordylophora caspia</i> (Cnidaria, Hydrozoa) en el embalse Río Tercero Mtro. Pistarini (Provincia de Córdoba, Argentina) y sus posibles impactos en este ecosistema

Cordylophora caspia (Pallas, 1771) is a euryhaline hydrozoan native to the Ponto-Caspian region but with a global distribution. It has a high invasive potential, largely due to its ability to adapt to a wide range of temperatures and salinity levels and to form resistant structures. It thrives in a great variety of freshwater and estuarine habitats, colonizing both natural and artificial substrates, where it causes serious biofouling issues. This species has been accidentally introduced into various regions worldwide, and in this publication, we report its first record in the Río Tercero Mtro. Pistarini Reservoir, Córdoba Province, Argentina. This is where the Embalse Nuclear Power Plant, which uses the reservoir’s waters as coolant, and the Fitz Simon hydroelectric power plant are situated. During monitoring conducted in August and October 2023 in the water intake systems of these facilities, colonies of C. caspia were found at approximately 18 meters in depth. Monitoring its populations is essential to understanding its ecological impact and implementing mitigation measures, as its control presents a challenge due to its high reproductive capacity, tolerance to different environmental conditions, and resistance to certain chemical treatments.