Distribution and its mechanisms of Branchinecta gaini (Branchiopoda: Anostraca) in the area of the Wilhelm Archipelago (Maritime Antarctica)

The anostracan Branchinecta gaini is the largest animal, the main consumer of detritus and benthos, and a background species of energy harvester in the trophic food chains of Antarctic freshwater bodies. This crustacean species was first recorded in the freshwater reservoir of Petermann Island (Wilhelm Archipelago, Maritime Antarctica) during the Second French Antarctic Expedition of Jean-Baptiste Charcot in 1909. This work aimed to investigate the current distribution and its mechanisms of B. gaini in the Argentine Islands of this archipelago. Branchinecta gaini was found during our research within the freshwater bodies of Uruguay and Galindez Islands in 2007. In addition, this species was registered in reservoirs of three islands in 2008, six islands in 2010, and nine islands in 2020. As a result, B. gaini was found in the 32 freshwater bodies of 12 islands in the Wilhelm Archipelago region and for the first time in reservoirs of 11 islands. Different ways and mechanisms of the distribution of B. gaini in extreme Antarctic conditions were also considered.