| Elysia timida | |
|---|---|
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| Right side view of Elysia timida | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Family: | Plakobranchidae |
| Genus: | Elysia |
| Species: | E. timida |
| Binomial name | |
| Elysia timida (Risso, 1818) | |
| Synonyms [1] | |
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Elysia timida is a species of sacoglossan sea slug, a marine opisthobranch gastropod mollusk. [1] Found in the Mediterranean and nearby parts of the Atlantic, it is herbivorous, feeding on various algae in shallow water.
Elysia timida is a small sea slug, growing to a length of about 12 mm (0.5 in). The head bears a pair of long, smooth rhinophores, at the base of which are a pair of black eyespots. The broad foot widens into two lobed parapodia which can fold up over the back. The colour is mainly white with widely scattered red or orange spots, but the dorsal surface of the body, and the inner surface of the parapodia, are some shade of mid- to dark green. When the animal has been living in a habitat with Lithophyllum or other pink calcareous algae, the white colour may be tinged with mauve. [2]
This marine species used to be considered endemic to the Mediterranean Sea, but has also been found in the Atlantic Ocean, off the Cape Verde and Canary Islands, and possibly in the Caribbean Sea. [3] It is found in sea grass beds and on rocks on which the algae on which it feeds is growing, at depths down to about 20 m (66 ft). [2]
Elysia timida feeds on the alga Acetabularia acetabulum in spring and summer, and on Padina pavonica in autumn. It is able to make use of the chloroplasts from the algae, storing them in outgrowths of its digestive gland, where they give the sea slug its green colour. This is called kleptoplasty. [2] The chloroplasts are able to continue photosynthesising in the slug's tissues for about 45 days, and contributing to the slug's nutritional requirements. The slug is able to regulate the process, folding its parapodia over its back to restrict the amount of light the chloroplasts receive, or unfolding its parapodia to allow the chloroplasts full access to the light. [2] [4]
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Elysia timida is a hermaphrodite and two individuals come together and mate simultaneously. With their right sides in close proximity, each uses its long penis to insert sperm into the tissues of the other. They then separate and loop round to rearrange themselves, this time depositing sperm into the recipient's genital opening. This second mating phase is sometimes omitted. The eggs are laid in the spring in a white spiral coil about a centimetre across. [2]
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Notarchus is a genus of sea slugs or sea hares, marine opisthobranch gastropod mollusks in the family Aplysiidae, the sea hares.
Sacoglossa are a superorder of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia known as sacoglossans. There are 284 valid species recognized within this superorder. Sacoglossans live by ingesting the cellular contents of algae, hence they are sometimes called "sap-sucking sea slugs". Some sacoglossans simply digest the fluid which they suck from the algae, but in some other species, the slugs sequester and use within their own tissues living chloroplasts from the algae they eat, a very unusual phenomenon known as kleptoplasty, for the "stolen" plastids. This earns them the title of the "solar-powered sea slugs", and makes them unique among metazoan organisms, for otherwise kleptoplasty is known only among other euthyneurans and single-celled protists.
Kleptoplasty or kleptoplastidy is a process in symbiotic relationships whereby plastids, notably chloroplasts from algae, are sequestered by the host. The word is derived from Kleptes (κλέπτης) which is Greek for thief. The alga is eaten normally and partially digested, leaving the plastid intact. The plastids are maintained within the host, temporarily continuing photosynthesis and benefiting the host.
Elysia subornata is a species of small sea slug, a marine opisthobranch gastropod mollusk in the family Plakobranchidae.
Elysia chlorotica is a small-to-medium-sized species of green sea slug, a marine opisthobranch gastropod mollusc. This sea slug superficially resembles a nudibranch, yet it does not belong to that clade. Instead it is a member of the clade Sacoglossa, the sap-sucking sea slugs. Some members of this group use chloroplasts from the algae they eat for photosynthesis, a phenomenon known as kleptoplasty. Elysia chlorotica is one species of such "solar-powered sea slugs". It lives in a subcellular endosymbiotic relationship with chloroplasts of the marine heterokont alga Vaucheria litorea.
Elysia viridis, the sap-sucking slug, is a small-to-medium-sized species of green sea slug, a marine opisthobranch gastropod mollusc in the family Plakobranchidae.
Elysia is a genus of sea slugs, marine gastropod molluscs in the family Plakobranchidae. These animals are colorful sea slugs, and they can superficially resemble nudibranchs, but are not very closely related to them. Instead they are sacoglossans, commonly known as sap-sucking slugs.
Elysia crispata, common name the lettuce sea slug or lettuce slug, is a large and colorful species of sea slug, a marine gastropod mollusk.
Elysia pusilla is a species of small sea slug, a marine gastropod mollusk in the family Plakobranchidae. It is a sacoglossan.
Elysia maoria is a species of marine gastropod mollusk in the family Plankobranchidae. It is found off of New Zealand.
Plakobranchus ocellatus is a species of sea slug, a sacoglossan, a marine opisthobranch gastropod mollusk in the family Plakobranchidae. It is found in shallow water in the Indo-Pacific region.
Elysia catulus is a small species of sea slug, a marine gastropod mollusc in the family Plakobranchidae. This sea slug resembles a nudibranch, but it is not closely related to that order of gastropods, instead it is a sacoglossan. The specific name "catulus" comes from the Greek and means "little cat", referring to the superficial resemblance that the head of this slug bears to the head of a cat.
Elysia margaritae is a species of sea slug, a marine gastropod mollusc.
Elysia australis is a species of sea slug, a marine gastropod mollusc in the family Plakobranchidae. This sea slug resembles a nudibranch, but it is not closely related to that order of gastropods, instead it is a sacoglossan. It occurs in Australia.
Elysia diomedea is a species of sea slug found throughout the Pacific coast of Central America.
Elysia trisinuata is a species of sea slug, a marine gastropod mollusc in the family Plakobranchidae. This sea slug resembles a nudibranch but is not closely related to that order of gastropods, instead belonging to another clade, Sacoglossa, the "sap-sucking" sea slugs.
Acetabularia acetabulum is a species of green alga in the family Polyphysaceae. It is found in the Mediterranean Sea at a depth of one to two metres.
Costasiella ocellifera is a small (5–13 mm) species of sea slug, a shell-less marine gastropod mollusk in the family Costasiellidae. Costasiella ocellifera, and other members of the Costasiellidae family are often mistakenly classified as nudibranchs because they superficially resemble other species of that group, but they are actually a part of the Sacoglossa superorder of sea slugs, also known as the “sap-sucking sea slugs,” "crawling leaves" or the "solar-powered sea slugs." C. ocellifera was discovered by Simroth in 1895, and was initially classified as Doto ocellifera. The Brazilian species, Costasiella liliana, is a synonym of C. ocellifera.Costasiella ocellifera shows long-term retention of functional kleptoplasty.
Elysia marginata is a marine gastropod in the family Plakobranchidae. It is known for its ability to regenerate its whole body and heart after autotomizing it from its head.
Philinopsis depicta is a species of sea slug, an opisthobranch gastropod mollusc in the family Aglajidae. It is native to the Mediterranean Sea where it lives on the sandy seabed in shallow water. It is a predator.
