First record of the fiddler crab Leptuca (=Uca) uruguayensis in the Bahía Blanca Estuary (Buenos Aires, Argentina) with comments on its biology in South America

Abstract

The occurrence of the fiddler crab Leptuca (=Uca) uruguayensis (Brachyura: Ocypodidae) in the Bahía Blanca Estuary (Buenos Aires, Argentina) is reported for the first time. The organisms had a small patchy distribution with high densities in an environment with silty-sandy sediments and low organic matter content, near the population of the dominant varunid crab Neohelice granulata. The presence of this species suggests that larvae of L. uruguayenesis may have been introduced into the estuary via the ballast water of ships. The field sampling was extended to other sites closer to this harbour to assess if the species was inhabiting other places within the estuary, but with no results. Within this framework, the monitoring of this population is fully recommended; moreover, it is necessary to keep monitoring other sites in order to assess if this species could settle in other places in the future.