''Acropora prolifera'', the fused staghorn coral, is a branching,

colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 au ...

, stony

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...

found in shallow parts 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 ...

, the Bahamas and southern Florida.

Description

''Acropora prolifera'' is very similar to staghorn coral (''Acropora cervicornis'') in appearance but usually forms smaller, denser clumps. The branches are mostly horizontal and often divide near the tip, sometimes fusing with other branches. It also resembles

elkhorn coral Elkhorn coral (''Acropora palmata'') is an important reef-building coral in the Caribbean. The species has a complex structure with many branches which resemble that of elk antlers; hence, the common name. The branching structure creates habita ...

(''Acropora palmata'') and genetic studies show that it is a

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

between that and staghorn coral. The

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, the

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

skeletal cups in which the polyps sit, are tubular and protrude from the surface of the branches. They are tightly packed and arranged in linear rows and there is a larger corallite at the tip of each branch. The branches are up to in diameter and the whole colony may grow to across. The general colour is pale yellowish-brown and the branches have paler tips.

Distribution

''Acropora prolifera'' is found in the Caribbean Sea, the Gulf of Mexico, the Bahamas and southern Florida southwards to Colombia and Venezuela. It is generally found on outer

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 processes— deposition of sand, wave erosion planing down rock out ...

slopes, in calm-water bays and in the lee of land masses, most commonly at a depth of around but occasionally down to about . It is generally an uncommon species.

Biology

Many reef corals have mass spawning events when vast numbers of gametes are released into the sea at the same time. This happens with elkhorn and stagshorn corals and when these

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

corals spawn at the same time,

F1 hybrid An F1 hybrid (also known as filial 1 hybrid) is the first filial generation of offspring of distinctly different parental types. F1 hybrids are used in genetics, and in selective breeding, where the term F1 crossbreed may be used. The term is somet ...

s can be formed. These cannot propagate sexually but can reproduce asexually to increase the number of individuals. In the case of ''Acropora prolifera'', hybrids come in two forms. Where the female gamete is derived from the elkhorn coral, the resulting offspring is bushy and compact. Where the female gamete comes from staghorn coral, the offspring adopts a more palmately dividing form. ''Acropora prolifera'' is a zooxanthellate coral, the tissues containing dinoflagellates which live

symbiotically Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

within the cells. 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 use the

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

and waste products of the coral while at the same time supplying oxygen and organic compounds to their host.

References

{{Taxonbar, from=Q3317601 Acropora Corals described in 1816