pteropod
noun
ptero·pod ˈter-ə-ˌpäd 
: any of the opisthobranch mollusks comprising two orders (Thecosomata and Gymnosomata) and having the anterior lobes of the foot expanded into broad thin winglike swimming organs
Example Sentences
Recent Examples on the Web Tiny swimming sea snails called pteropods that make up 40 percent of the diet of juvenile pink salmon already are showing extensive shell corrosion in both the Gulf of Alaska and Bering Sea. 
Anchorage Daily News, 24 Mar. 2020 Early victims of ocean acidification include pteropods, microscopic floating snails that make up a huge portion of the diets of juvenile pink salmon. Anchorage Daily News, 15 Oct. 2019 Mucous-mesh grazers include salps, pyrosomes, doliolids, pteropods and appendicularians. Kelly Sutherland, Smithsonian, 3 May 2018 Already, the shells of some animals are thinning, plankton are having trouble growing, and sea animals ranging from scallops to pteropods are dying out. Sena Christian, Newsweek, 19 Nov. 2015
Anchorage Daily News, 24 Mar. 2020 Early victims of ocean acidification include pteropods, microscopic floating snails that make up a huge portion of the diets of juvenile pink salmon. Anchorage Daily News, 15 Oct. 2019 Mucous-mesh grazers include salps, pyrosomes, doliolids, pteropods and appendicularians. Kelly Sutherland, Smithsonian, 3 May 2018 Already, the shells of some animals are thinning, plankton are having trouble growing, and sea animals ranging from scallops to pteropods are dying out. Sena Christian, Newsweek, 19 Nov. 2015 Word History
Etymology
New Latin Pteropoda, group name, from Greek pteron wing + New Latin -poda
First Known Use
1833, in the meaning defined above