Elysia viridis
Encyclopedia
Elysia viridis or the sap-sucking slug is a small-to-medium-sized species
of green sea slug
, a marine
opisthobranch gastropod mollusc in the family
Placobranchidae.
This sea slug resembles a nudibranch
, but it is not closely related to that order of gastropods. It is instead a sacoglossa
n.
to the Mediterranean Sea
as well as all around the South African coast. It is found from the intertidal to about 5 m.
s are rolled.
relationship with chloroplast
s derived from the alga
Codium fragile
. These chloroplasts provide the Elysia host with the products of photosynthesis
. Elysia viridis feeds on Codium, and absorbs its chloroplast
s. These are then retained unharmed in the slug's body and the photosynthetically derived sugars produced are used by the slug to supplement its diet. The egg mass is a flat greenish coil of several turns.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of green sea slug
Sea slug
Sea slug is a common name used for several different groups of saltwater snails that either lack a shell or have only an internal shell, in other words this name is used for various lineages of marine gastropod mollusks that are either not conchiferous or appear not to be.The phrase "sea slug" is...
, a marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
opisthobranch gastropod mollusc in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Placobranchidae.
This sea slug resembles a nudibranch
Nudibranch
A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...
, but it is not closely related to that order of gastropods. It is instead a sacoglossa
Sacoglossa
Sacoglossa, commonly known as the sacoglossans or the "sap-sucking sea slugs", are a clade of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia...
n.
Distribution
This species lives in the northeastern Atlantic, from NorwayNorway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
to the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
as well as all around the South African coast. It is found from the intertidal to about 5 m.
Description
The animal grows up to 30 mm in total length. It has a smooth bright green or brown body with iridescent spots and two wing-like flaps extending along its sides. These flaps are usually folded back. The rhinophoreRhinophore
A rhinophore is one of a pair of club-shaped structures which are the most prominent part of the external head anatomy of a group of sea slugs, marine gastropod opisthobranch mollusks in the order Nudibranchia, the nudibranchs, specifically the dorid nudibranchs.- Etymology :The name relates to the...
s are rolled.
Ecology
This species lives in a subcellular endosymbioticEndosymbiont
An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis...
relationship with chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
s derived from the alga
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
Codium fragile
Codium fragile
Codium fragile, also known as Green sea fingers, Dead man's fingers, felty fingers, felt-alga, Green sponge and Green fleece is an invasive species of seaweed in the family Codiaceae....
. These chloroplasts provide the Elysia host with the products of photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
. Elysia viridis feeds on Codium, and absorbs its chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
s. These are then retained unharmed in the slug's body and the photosynthetically derived sugars produced are used by the slug to supplement its diet. The egg mass is a flat greenish coil of several turns.