''Lasaea rubra'' 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

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 * ...

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

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 ...

Lasaeidae Lasaeidae is a family of very small saltwater clams, marine bivalve molluscs in the order Galeommatida. These bivalves are sometimes called "kelly clams", because one of the genera in this family is ''Kellia''. Genera and species Genera and s ...

. It is found on the eastern side of the Atlantic Ocean. This species was first described in 1803 by the English naturalist George Montagu who gave it the name ''Cardium rubrum''. It was later transferred to the genus ''

Lasaea Lasaea or Lasaia ( grc, Λασαία) was a city on the south coast of ancient Crete, near the roadstead of the "Fair Havens" where apostle Paul landed. This place is not mentioned by any other writer, under this name but is probably the same as ...

'', making it ''Lasaea rubra''.

Description

This small mollusc has a maximum length of about . The shell is oval, thin and fragile, with both valves convex. The umbones are slightly behind the midline, both valves having a single lateral tooth on each side of the hinge with the left valve having in addition, a cardinal tooth. The ligament is internal and passes through a deep groove below the hinge in each valve, and has a broad plate beneath the hind lateral teeth. The valves are finely sculptured with closely spaced concentric lines, and the annual growth rings are clearly visible. Externally, the valves are white with pink or brownish concentric bands, and internally it is white: the adductor scars are large and the

pallial line The pallial line is a mark (a line) on the interior of each valve of the shell of a bivalve mollusk. This line shows where all of the mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle m ...

broad but indistinct.

Distribution and habitat

''Lasaea rubra'' is native to the eastern Atlantic Ocean where its range extends from

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

through 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 ...

to the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

and 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 ...

. It is found in the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

on rocky shores, lodged in crevices, in tufts of lichen or among the holdfasts ad fronds of

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

, attached by

byssus A byssus () is a bundle of filaments secreted by many species of bivalve mollusc that function to attach the mollusc to a solid surface. Species from several families of clams have a byssus, including pen shells (Pinnidae), true mussels (Mytilid ...

threads.

Biology

''Lasaea rubra'' is a simultaneous

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

and the eggs are retained inside the mantle cavity while they develop. The veliger larval stage is omitted from the life cycle and when fully developed, juvenile molluscs are released and crawl away from the parent. Adults are found to be able to move in a day and juveniles twice that distance. The majority of individuals inhabiting the same rock crevice are found to be clones of each other, having been developed

parthenogenetically Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...

from a common ancestor.

References

{{Taxonbar, from=Q3804678 Lasaeidae Molluscs of the Atlantic Ocean Molluscs of the Mediterranean Sea Taxa named by George Montagu (naturalist) Molluscs described in 1803