''Carditamera affinis'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of marine

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

. It was first described to science by

George Brettingham Sowerby I George Brettingham Sowerby I (12 August 1788 – 26 July 1854) was a British natural history, naturalist, illustrator and Conchology, conchologist. Life He was the second son of James Sowerby. George was educated at home under private tutors, ...

in 1833. No English common name has been recorded for this species. The first appearance of this animal in the fossil record is 5.333 million years ago.

Description

The shell is roughly trapezoidal with 15 raised ribs. In some individuals, small spines or scales are found on the posterior ends (furthest from the hinge) of the larger ribs. The shell is colored in brown shades both on its exterior and interior. Shells have been recorded between 50.7mm and 101.2mm (2 to 4 inches) long.

Distribution

''Carditamera affinis'' is found in the eastern Pacific Ocean from

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

. It is also found in the

Gulf of California The Gulf of California (), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Vermejo''), is a marginal sea of the Pacific Ocean that separates the Baja California peninsula from ...

and was one of the specimens collected there by

John Steinbeck John Ernst Steinbeck ( ; February 27, 1902 – December 20, 1968) was an American writer. He won the 1962 Nobel Prize in Literature "for his realistic and imaginative writings, combining as they do sympathetic humor and keen social percep ...

and

Ed Ricketts Edward Flanders Robb Ricketts (May 14, 1897 – May 11, 1948) was an American marine biologist, ecologist, and philosopher. Renowned as the inspiration for the character Doc in John Steinbeck's 1945 novel '' Cannery Row'', Rickett's professional ...

, as recounted in ''

The Log From The Sea Of Cortez ''The Log from the Sea of Cortez'' is an English-language book written by American author John Steinbeck and published in 1951. It details a six-week (March 11 – April 20) marine specimen-collecting boat expedition he made in 1940 at variou ...

''. In 2012 a very similar looking species, ''Carditamera bajaensis'', was split from ''C. affinis''. Both species occur in the Gulf of California, but in different habitats. While ''C. affinis'' is

epifaunal Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and ''funga'', respectively. Flora, fauna, funga and other forms of life are collectively r ...

, that is it lives at the surface of the seabed on rocks and in crevices, ''C. bajaensis'' is infaunal or semi-infaunal, living completely or partly buried in sand, mud, or loose rocks. ''C. affinis'' is also found in the Galapagos Islands. This is a shallow-water species, living from the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

down to 27 meters (90 feet) deep.

Life history

''Carditamera affinis'' is a

filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ...

, straining nutrients from sea water that it pumps through its body. It is sessile as an adult, attaching itself to rocks and within crevices using a

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 (Mytili ...

. These animals can live as long as 17.25 years.

References

{{Taxonbar, from=Q13455189 Carditidae Bivalves of North America Bivalves described in 1833