''Diploria'' is a monotypic genus of massive reef building stony corals in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Mussidae. It is represented by a single species, ''Diploria labyrinthiformis'', commonly known as grooved brain coral and is found in the western Atlantic Ocean and

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

. It has a familiar, maze-like appearance.

Description

This species of

reef A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic (non-living) processes such as deposition (geol ...

-building coral has a hemispherical, brain-like shape with a brown, yellow, or grey colour. It has characteristic deep, interconnected double-valleys. These polyp-bearing valleys are each separated by grooved ambulacral ridges. There may be a difference in colour between the valleys and the grooves. ''Diploria labyrinthiformis'' can grow upward at a rate of approximately 3.5 millimeters per year, achieving about in diameter. During its planktonic larval stage, the coral has locomotion. After that time, it becomes permanently sessile. This species is a

suspension 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 spec ...

, and survives mainly on

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

and

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

. These are captured by the polyps, by extruding mesenterial filaments and tentacles. The polyps have nematocysts which are triggered to hold their prey immobile. The prey is then transported to the mouth with the assistance of

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

and

cilia The cilium (: cilia; ; in Medieval Latin and in anatomy, ''cilium'') is a short hair-like membrane protrusion from many types of eukaryotic cell. (Cilia are absent in bacteria and archaea.) The cilium has the shape of a slender threadlike proj ...

. ''Diploria labyrinthiformis'' is hermaphroditic, and reproduces through broadcast spawning. This entails eggs and

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

being released by adult colonies, followed by

fertilization Fertilisation or fertilization (see American and British English spelling differences#-ise, -ize (-isation, -ization), spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give ...

and the development of

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

at the water surface. Unlike most other Caribbean broadcast spawners, ''Diploria labyrinthiformis'' spawns over multiple months from the late spring until even mid-autumn.

Distribution and habitat

''Diploria labyrinthiformis'' is found in tropical parts of the west Atlantic Ocean, the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

, the

, the southern tip of

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

, the

Bahamas The Bahamas, officially the Commonwealth of The Bahamas, is an archipelagic and island country within the Lucayan Archipelago of the Atlantic Ocean. It contains 97 per cent of the archipelago's land area and 88 per cent of its population. ...

Bermuda Bermuda is a British Overseas Territories, British Overseas Territory in the Atlantic Ocean, North Atlantic Ocean. The closest land outside the territory is in the American state of North Carolina, about to the west-northwest. Bermuda is an ...

and the coasts of

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

. This coral occurs offshore at depths ranging from . The Diploria coral is important to its environment because it helps researchers see how the oceans temperature has changed over time by looking at the layers in the coral skeleton.

Status

This species was listed as

Least Concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

for years on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

, however the most recent assessment in 2021 has resulted in a sudden uplisting due to the species' predicted decline, in part due to its susceptibility to Stony Coral Tissue Loss Disease.

Relationships with other species

Symbiotic

''Diploria labyrinthiformis'' hosts Zooxanthella, a

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

dinoflagellate The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also commo ...

alga Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...

. The alga benefits from being in a protective environment in an elevated position. The coral benefits from the nutrients produced photosynthetically by the alga which provides part of its needs for growth and calcification. The coral also has a relationship with '' Diadema antillarum'', the long-spined urchin, whose grazing helps to reduce the effects of shading, as well as the overgrowth of

macroalgae Seaweed, or macroalgae, refers to thousands of species of Macroscopic scale, macroscopic, Multicellular organism, multicellular, ocean, marine algae. The term includes some types of ''Rhodophyta'' (red), ''Brown algae, Phaeophyta'' (brown) and ...

Predators

Despite the polyps being equipped with nematocysts, various species prey upon ''Diploria labyrinthiformis''. These include: *Gastropods *Polychaetes ( annelid worms) *Sea urchins *Starfishes *Sea spiders *Parrotfish and other fishes

Parasites

This species is host to a

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

in the '' Corallovexiidae'' family: *'' Corallovexia brevibrachium'' is both an

ectoparasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

and an

endoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...

Taxonomy

In the past, other species were classified as pertaining to the Diploria genus. Some of those species are now classified as Pseudodiploria, a genus erected in 2012, such as P. strigosa and P. clivosa.

Reproduction

''Diploria labyrinthiformis'' is hermaphroditic, employing a broadcast-spawning method to reproduce. As with most coral species, timing of gamete release is related to moon cycles. Exact timing of this event can vary, even within its regional range, but is typically earlier in the year than many other scleractinian species in the Caribbean

Postage stamps

Images of ''Diploria labyrinthiformis'' appear on three postage stamps: a 75 cent

Belize Belize is a country on the north-eastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a maritime boundary with Honduras to the southeast. P ...

an stamp created by Georges Declercq, a 15 cent stamp from

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

issued 1980-08-26 and a 54 Euro cent stamp from

Mayotte Mayotte ( ; , ; , ; , ), officially the Department of Mayotte (), is an Overseas France, overseas Overseas departments and regions of France, department and region and single territorial collectivity of France. It is one of the Overseas departm ...

References

External links

Image of postage stamp from BelizeImage of postage stamp from Mayotte
{{Authority control Faviinae Corals described in 1758 Taxa named by Carl Linnaeus Taxa named by Henri Milne-Edwards Taxa named by Jules Haime Scleractinia genera