Freshwater stingrays in South America: From Lake Maracaibo to the Arari, the surprising habitats of rare river rays

Stingrays are usually associated with coastal waters, but some species have adapted to life far from the sea. In South America, freshwater stingrays inhabit rivers, floodplains, lagoons and lakes. Their presence is especially striking in seasonal floodplain systems, where changing water levels can connect lakes with rivers and flooded forests. Lake Maracaibo in Venezuela is home to the endangered Maracaibo River Stingray, while Brazil’s Lake Arari, Janauacá Lake and Catalão Lake support freshwater stingray species associated with the Amazon basin. Catalão Lake is particularly notable because it has been identified as a reproductive area for the Ocellate River Stingray.South American lakes where freshwater stingrays are foundLake Maracaibo, VenezuelaLake Maracaibo covers about 13,280 square kilometres and reaches roughly 35 metres at its deepest point. The Maracaibo River Stingray, Potamotrygon yepezi, is a strictly freshwater species associated with the Maracaibo basin. It is not found throughout the lake itself, but occurs in surrounding waters and rivers that feed the lake. The species appears to favour soft muddy or sandy bottoms and can reach about 40 centimetres in length. It is classified as Endangered by IUCN.Lake Arari, BrazilLake Arari lies on Marajó Island in Pará, near the mouth of the Amazon River. Researchers found the Ocellate River Stingray, Potamotrygon motoro, there while studying freshwater stingray diets on Marajó Island. According to a 2010 study published in the Brazilian Journal of Biology, titled “Diet of the freshwater stingray Potamotrygon motoro (Chondrichthyes: Potamotrygonidae) on Marajó Island (Pará, Brazil)”, researchers analysed the stomach contents of 137 stingrays and found that fish were the most important food group recorded in specimens from Lake Arari. The study also identified insects, molluscs, crustaceans and annelids among the food items found across the locations studied.Janauacá Lake, BrazilJanauacá Lake lies within the Amazon floodplain near Manaus. Surveys have documented four freshwater stingray species, which include Potamotrygon motoro, Potamotrygon scobina, Potamotrygon orbignyi and Paratrygon aiereba. Seasonal changes in water levels periodically connect the lake with surrounding floodplain habitats, helping explain how stingrays occur across linked rivers, lakes and flooded forests.Catalão Lake, BrazilCatalão Lake is a floodplain lake near the meeting of the Solimões and Negro rivers in Amazonas. Researchers recorded Potamotrygon motoro there during field surveys in 2014 and 2015. According to the 2025 Catalão Lake ISRA Factsheet, published by the IUCN SSC Shark Specialist Group, the lake is an important reproductive area for the Ocellate Freshwater Stingray. The assessment was based on surveys that captured 20 stingrays, including nine females and 11 males.Why are freshwater stingrays rarely found in lakesFreshwater stingrays are unusual because most stingrays are associated with marine environments. The species found in South American lakes have adapted to freshwater habitats, including rivers, floodplains, lagoons, and seasonally connected lakes. In the Amazon basin, changing water levels can connect lakes with rivers and flooded forests, allowing aquatic species to move between habitats.Some lakes also have particular importance for stingray populations. Catalão Lake, for example, has been recognised as a reproductive area for the Ocellate River Stingray, Potamotrygon motoro. Lake Maracaibo is home to the Maracaibo River Stingray, Potamotrygon yepezi, which is restricted to the Maracaibo basin and classified as Endangered. These examples highlight the specialised freshwater environments where these rays survive.Catch the latest World News and Live updates. Download the TOI app.