''Trivia monacha'', also known as the European cowrie or spotted cowrie, 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

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 ...

Triviidae Triviidae is a taxonomic family of small sea snails, marine gastropod molluscs in the superfamily Cypraeoidea of the order Littorinimorpha. MolluscaBase eds. (2020). MolluscaBase. Triviidae Troschel, 1863. Accessed through: World Register of Mari ...

, the trivias. The name ''Trivia'' means "common" and the word ''monacha'' means "solitary". It is worth comparing this species with the similar species ''

Trivia arctica ''Trivia arctica'', the northern cowrie, is a species of small sea snail, a marine gastropod mollusc in the family Triviidae, the trivias. This is a similar species to ''Trivia monacha'' and it often occurs in the same areas. The name ''Triv ...

'', the northern cowrie.

Shell description

The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard ou ...

of this species is glossy, convolute and lemon-shaped, with 20-30 transverse ridges. The dorsal part of the shell is a pinkish or reddish-brown with three characteristic darker spots in mature individuals, one spot anterior, the other posterior and one in the centre, all situated along a central line. Juvenile shells are all white or light-coloured. The apertural side is white and flattened. The aperture is narrow and runs along the whole length of the shell. At the ends it turns to the left in the direction of the swollen body

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

. The transverse ridges are strong and often bifurcate. The ones at the ends are almost U-shaped. The shell length is up to a maximum of about 15 mm and its width about 8 mm. The dark mantle is covered by few

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

e, usually tipped with pale yellow. The mantle is drawn out into a long

siphon A siphon (from grc, σίφων, síphōn, "pipe, tube", also spelled nonetymologically syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in a ...

anteriorly, extending over the whole (or almost the whole) shell. The foot is orange or bright yellow. The breeding season is late spring or summer. The larvae have a very dark stomach and intestine. More developed larvae in the

veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod ...

stage have a two-lobed velum (a structure used for swimming and particulate food collection) that is slightly indented at sides. The larvae reach the adult form in about five to six months.

Distribution

This species occurs from 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 ...

to the Shetland archipelago in the north of

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

, but is more common in the south. In Orkney and some parts of Scotland, the species are known as 'groatie buckies'.

Habitat

This species usually lives on rocky shores or under stones below low tide, in other words is

sublittoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

, but the empty shells of this species are often washed up onto beaches. It is usually found together with compound

ascidian 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" ...

s ('' Botrylus'',''

Botrylloides ''Botrylloides'' is a genus of ascidian tunicates in the family Styelidae. Description Like ''Botryllus'', ''Botrylloides'' are flat sheets of organisms which can be found covering ropes, boat hulls, horseshoe crabs, seaweeds, and any still or s ...

'' and '' Diplosoma''). Trivia monacha lacks small denticles on the admedian teeth of the radula. Furthermore, the rows of teeth in the two species are different.

Feeding habits

This snail feeds on

sea squirt Ascidiacea, commonly known as the ascidians, tunicates (in part), and sea squirts (in part), is a polyphyletic class (biology), class in the subphylum Tunicate, Tunicata of sac-like marine (ocean), marine invertebrate filter feeders. Ascidians ar ...

s and compound

Similar species

''Trivia monacha'' is sometimes confused with ''

''. In fact they were considered to be two forms of the same species until 1925, when

Alfred James Peile Alfred James Peile (5 August 1868 – 13 July 1948) was a British army officer and amateur malacologist who was an expert on the radulae of gastropods. Life Peile was educated at Cheltenham College and trained at the Royal Military Academy ...

published a paper in the ''

Proceedings of the Malacological Society The ''Journal of Molluscan Studies'' is the peer-reviewed scientific journal of the Malacological Society of London, covering research in malacology.

'' differentiating the two.Peile A. J. (1925). "The Differentiation as Species of the two forms of British ''Trivia''". ''Proc. Malac. Soc.'' 1925, pp: 195-198. They can be differentiated by the

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

, the shape of the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...

and their

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

l stages. In ''Trivia monacha'' the penis is filiform and cylindrical, while in ''Trivia arctica'' the penis is large and flat. It is now known that the

e of the two species are readily distinguishable. The Linnaean name ''Trivia europea'', now lapsed, referred to the supposed single species. Linnaeus himself mentioned two kinds: ''Cypraea europea'' and ''Cypraea anglica'', but these terms were intended as a geographical distinction and are not accepted as species names today.

References

External links

Arkive.org: ''Trivia monacha''

Sabella.mba.ac.uk : The_British_species of ''Trivia'' : ''T. arctica''_and ''T. monacha''
* P.J. Wayward & J.S. Ryland, ''Handbook of the Marine Fauna of North-West Europe'', Oxford University Press, Oxford, 1996, * {{Taxonbar, from=Q1377381 Triviidae Molluscs of the Atlantic Ocean Molluscs of the Mediterranean Sea Taxa named by Emanuel Mendes da Costa Gastropods described in 1778