The fairy shrimp Branchinecta gaini Daday is the largest freshwater invertebrate in Antarctica. Despite growing evidence of faunal endemism, it is believed to represent a mid- to late Holocene immigrant (Gibson & Bayly 2007, Hawes 2009, 2015).
To complete its life cycle, a significant period with liquid water is needed and subzero temperatures represent a real physiological constraint on adult animals. Its success in the extreme environment of Antarctica is associated with a 'ruderal' strategy that consists of metabolic eurythermy and formation of highly resistant cysts suitable for passive dispersal (Hawes et al. 2008, Hawes 2009).