Elysia clarki is a species

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 sacoglossan

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...

 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...

 gastropod mollusk in the family Placobranchidae.

Description

Elysia clarki attains relatively large size (up to 35 mm). Unlike the case for many Elysia species, which are tiny.

Elysia clarki is a relatively cryptic species (has cryptic coloration).

Ecology

It inhabits low wave energy habitats, such as mangrove swamps, borrow pits, and mooring canals.

It feeds suctorially on several species of siphonaceous green algae including Penicillus capitatus

Penicillus capitatus

Penicillus capitatus is a species of green algae.- References :*...

, Penicillus lamourouxii, Halimeda incrassata, Bryopsis plumosa, and Derbesia tenissima. The slug sequesters the 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 from all of these species and uses them for 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...

.
Furthermore, Elysia clarki photosynthesizes using the stored chloroplasts for up to three months without ingesting food. This species is one of the so-called "solar-powered sea slugs". Elysia clarki is an excellent organism for evaluating the relationship between kleptoplasty

Kleptoplasty

Kleptoplasty or kleptoplastidy is a symbiotic phenomenon whereby plastids from algae are sequestered by host organisms. The alga is eaten normally and partially digested, leaving the plastid intact. The plastids are maintained within the host, temporarily retaining functional photosynthesis for use...

 and feeding behavior, because observations of feeding behavior and measurements of photosynthesis are possible with Elysia clarki. Its photosynthetic capability (because of its kleptoplasty) has been shown to affect its foraging behavior under starvation

Starvation

Starvation is a severe deficiency in caloric energy, nutrient and vitamin intake. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death...

 conditions. 2011 was the first time that this connection was demonstrated for any organism within the animal kingdom.

External links

• http://www.seaslugforum.net/find/elysclar
• Curtis N. E., Massey S. E. & Pierce S. K. (2006). "The symbiotic chloroplasts in the sacoglossan Elysia clarki are from several algal species". Invertebrate Biology 125: 336-345. doi:10.1111/j.1744-7410.2006.00065.x. PDF.