The sea lettuces comprise the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Ulva, a group of edible green algae that is widely distributed along the coasts of the world's ocean

Ocean

An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

s. The type species within the genus Ulva is Ulva lactuca

Ulva lactuca

Ulva lactuca Linnaeus, a green alga in the division Chlorophyta, is the type species of the genus Ulva, also known by the common name sea lettuce.-Description:...

Linnaeus, "lactuca" meaning lettuce. Additionally, some species in the algae genus Monostroma

Monostroma

In taxonomy, Monostroma is a genus of algae, specifically of the Monostromataceae.-Scientific databases:* * *...

are known as slender sea lettuces.

Sea lettuce is eaten by a number of different sea animals, including manatee

Manatee

Manatees are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows...

s and the sea slugs known as sea hare

Sea hare

The clade Aplysiomorpha, commonly known as Sea hares or Sea Bags , are medium-sized to very large Opisthobranchia with a soft internal shell made of protein...

s.