''Agaricia agaricites'', commonly known as lettuce coral or tan lettuce-leaf coral, 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 colonial

stony corals Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mo ...

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 ...

Agariciidae The Agariciidae are a family of reef-building stony corals. This family includes cactus corals, plate corals, and lettuce corals. Members of the family include symbiotic algae called zooxanthellae in their tissues which help provide their energ ...

. This coral is found in shallow waters in the tropical western Atlantic Ocean and the Caribbean Sea. The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed its status as being oVuknerable.

Description

Colonies of ''A. agaricites'' have several different habits of growth, but usually occur in encrusting sheets with irregular projections or are leaf-like or plate-like. New colonies are usually encrusting, but vertical lobes and sheet-like projections begin to develop when the colonies are still quite small. The growth form seems to be partially linked to the movement of water in the vicinity and the depth. Horizontal plates normally have

corallite A corallite is the skeletal cup, formed by an individual stony coral polyp, in which the polyp sits and into which it can retract. The cup is composed of aragonite, a crystalline form of calcium carbonate, and is secreted by the polyp. Corallit ...

s on both sides while vertical forms have

s on only one side. The corallites are arranged in long meandering rows, but a few are single, with sharp-pointed ridges between them. Each one has up to 36

septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five coun ...

and a central spongy columella. This coral is a brown or purplish-brown colour.

Distribution and habitat

''A. agaricites'' is native to the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

, the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

and

the Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the Atlantic Ocean, North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to ...

, and is also present on the coast of Brazil, the Fernando de Noronha islands and the Rocas Atoll. It occurs in both fore and back-reef environments, channels, lagoons and

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s, at depths down to about .

Ecology

This coral is a

zooxanthellate Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''Symbi ...

species, which contains single-celled dinoflagellates in its tissues. These are

photosynthetic Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...

and provide the coral with 70% to 95% of its energy needs. The rest of its needs are supplied by the polyps which expand at night and trap passing

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 ...

. This is a small and relatively short-lived species but new young colonies are frequently to be found. This coral recruits readily to open patches of reef in the western Atlantic but could be considered a "coral weed" as it contributes little to reef development. In the

United States Virgin Islands The United States Virgin Islands,. Also called the ''American Virgin Islands'' and the ''U.S. Virgin Islands''. officially the Virgin Islands of the United States, are a group of Caribbean islands and an unincorporated and organized territory ...

, where a plume of sediment had killed a section of fore-reef, within a few years ''A. agaricites'' had proliferated and provided almost complete cover. ''A. agaricites'' is susceptible to

bleaching Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to ...

. In 1997, during an

El Niño Southern Oscillation EL, El or el may refer to: Religion * El (deity), a Semitic word for "God" People * EL (rapper) (born 1983), stage name of Elorm Adablah, a Ghanaian rapper and sound engineer * El DeBarge, music artist * El Franco Lee (1949–2016), American po ...

year with raised seawater temperatures off the coast of Brazil, this coral was the most affected coral species, with 80% of the individual colonies being bleached. When the water temperature returned to more normal levels, the colonies were slow to recover, but six months later, neither bleached nor dead colonies were found.

Status

''A. agaricites'' is a common coral and in some areas is the dominant species of coral. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed its conservation status as being Vulnerable.

References

{{Taxonbar, from=Q3949244 Agariciidae Corals described in 1758 Taxa named by Carl Linnaeus