Millions of tiny sea butterflies have made a brief appearance. These creatures are actually tiny, free-swimming marine snails. They are given their name due to their wing-like swimming appendages, which give them a butterfly-like appearance.

The name sea butterflies is a reference to their unique swimming appendages. Further details about this phenomenon are available from the source. More information can be found about these tiny marine snails and their brief visit, including their appearance and behavior, from the original report.