Sea butterfly

Common card · No. 311871

The Thecosomata (collective/plural: thecosomes, from Ancient Greek θήκη (thḗkē), meaning "case", and σῶμα (sôma), meaning "body"), or sea butterflies, are a taxonomic suborder of small, pelagic, free-swimming sea snails known as holoplanktonic opisthobranch gastropod mollusks, in the order Pteropoda (also included within the informal group Opisthobranchia). Most pteropods have some form of calcified shell, although it is often very light, even translucent. The sea butterflies include some of the world's most abundant gastropod species; as their large numbers are an essential part of the ocean food chain, they are a significant contributor to the oceanic carbon cycle.

Read on Wikipedia · Image Photo by Russ Hopcroft, University of Alaska, Fairbanks., Public domain