Recluzia lutea (Bennett, 1840), synonym: Recluzia rollandiana Petit de la Saussaye, 1853, is a species of a marine pelagic snail. This means that this snail does not live on the sea bottom, but it lives in the water column. Surprisingly this snail has no swimming fins. This species does not live in the whole water column, but in its the most upper part, closer to the surface level. Therefore it is a part of neuston and such gastropods are called neustonic gastropods. Simply said: Recluzia lutea float on the sea surface. There is also the term ‘plankton’ used for these gastropods: that means it is only able to drift and it cannot swim against the water current. This species is holoplanktonic, which means that it is planktonic for its entire life. It live under a raft-like float made from air bubbles and mucus. It has not yet been observed how the float is constructed by Recluzia.
These shells of Recluzia lutea were found way up in the Matinhos River, Paraná state, in southern Brazil, after a storm event, and sent to the Zoology museum in São Paulo.
Beu A. G. 2017: Evolution of Janthina and Recluzia (Mollusca: Gastropoda: Epitoniidae). Records of the Australian Museum, 69(3): 119–222. DOI: 10.3853/j.2201-4349.69.2017.1666
S. van der Spoel, L.J. Newman & K.W. Estep (accessed December 13, 2018) Recluzia rollandiana. Marine Species Identification Portal.