(A) Halobiotus crispae in active stage from Vellerup Vig, Denmark (20 ppt). (A) Halobiotus crispae in active stage from Vellerup Vig, Denmark (20 ppt). Light-microscopical images at different time points following exposure to 2 ppt (62 mOsm kg–1) of a single specimen (scale bar=100 μm). (B) Changes in total body volume (▪) and measured internal osmolality (○) over a period of 48 h following exposure to an external salinity of 2 ppt. Data are expressed as means ± s.d. Numbers in parentheses indicate the number of animals used for assessment of body volume and hemolymph osmolality at each time point. Kenneth Agerlin Halberg et al. J Exp Biol 2009;212:2803-2811 ©2009 by The Company of Biologists Ltd