Morphology and phenotypic plasticity of the different Droopiella species. (23-28) D. spaerckii and (29-30) D. capsulata under freshwater (23,25,27,29), and marine conditions (24,26,28,30). Strains: (23-24) CCAP 211/20; (25-26) CCAP 211/29A; (27-28) CCAP 211/29B; (29-30) UTEX 2074; (31-45) D. limnetica sp. nov. (SAG 2074) under freshwater conditions; (46-55) D. spaerckii (SAG 30.96) under brackish conditions; scale bar = 10 μm.