''Lamellaria perspicua'', commonly known as the transparent lamellaria, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of small, slug-like

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Velutinidae Velutinidae is a family of small sea snails, marine gastropod molluscs in the clade Littorinimorpha.Gofas, S. (2014). Velutinidae Gray, 1840. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetail ...

. It is native to the northeastern Atlantic Ocean and the Mediterranean Sea, where it feeds on

colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 au ...

ascidians Ascidiacea, commonly known as the ascidians, tunicates (in part), and sea squirts (in part), is a polyphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" ...

(sea squirts).

Description

The shell is not visible externally because it is completely surrounded by the mantle. The shell is thin, smooth and fragile, and consists of two to three whorls with a short spire. The last whorl is 95% of the total height of the shell. The aperture is very wide and somewhat spoon-shaped, being extended slightly to the right. There is no operculum and the shell is up to long. The animal grows to about long by wide and is oval in shape, with a siphonal notch at the front. The dorsal surface of the mantle bears tubercular projections, the margins are thickened and there is a siphon-like extension at the front. The colour is variable, varying from grey to lilac, yellowish, buff or orange, sometimes with black flecks.

Distribution and habitat

''Lamellaria perspicua'' is native to the northeastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. Its range extends from Iceland and Norway southwards to the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

and includes the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

and the

English Channel The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...

. Its depth range is from low water at spring tides down to about . It conceals itself under rocks and can be found in areas where compound

grow.

Ecology

This snail both feeds on ascidians and lays its eggs on them. The colour and texture of the mollusc often closely resemble the surface of the compound ascidian on which it is living, which fact renders the mollusc well-

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the ...

d. Some individuals have red patches which resemble small colonies of

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

, and others have been observed with the tubercles coloured in such a way as to resemble acorn barnacles. These colourings make it difficult for potential predators to detect the molluscs, and another defensive mechanism is acid-secreting glands in the dorsal

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

that make the molluscs distasteful to fish. Lamellaria perspicua eggs

Breeding takes place in spring and summer in this species. The sexes are separate and fertilisation is internal. The female deposits batches of up to 3000 eggs in capsules deposited in holes she has gnawed in the ascidian colony. The larvae hatch after about three weeks and are

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

, probably drifting with the

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

for quite a long time.

References

{{Taxonbar, from=Q4937321 Velutinidae Gastropods described in 1758 Taxa named by Carl Linnaeus