Cardiapoda placenta, Gastropoda, Sea elephant, Heteropod, holoplanktonic gastropods, marine gastropod molluscs in the clade Littorinimorpha, pelagic snails (Class Gastropoda), Plankton, planktonic marine life, Pterotracheoidea, shell-less pelagic mollusc, Vertical migration, vulnerable to the effects of ocean acidification, Gulf Stream current, Florida