Coralline rock

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Coralline rocks on the Zanzibar Coast FANTASTIC CORALLINE ROCKS ON THE ZANZIBAR COAST.png
Coralline rocks on the Zanzibar Coast

Coralline rock is a type of rock formed by the death of layers of coralline algae. It is visually quite bright like the algae, and is often desired as aquarium decoration. Since it is formed from the dead algae, it contains some nutrients and calcium carbonate, which has allowed it to be used in some building structures.

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<span class="mw-page-title-main">Limestone</span> Sedimentary rocks made of calcium carbonate

Limestone is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of CaCO3. Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life.

<span class="mw-page-title-main">Reef</span> A shoal of rock, coral or other sufficiently coherent material, lying beneath the surface of water

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 (non-living) processes such as deposition of sand or wave erosion planing down rock outcrops. However, reefs such as the coral reefs of tropical waters are formed by biotic (living) processes, dominated by corals and coralline algae. Artificial reefs such as shipwrecks and other man-made underwater structures may occur intentionally or as the result of an accident, and are sometimes designed to increase the physical complexity of featureless sand bottoms to attract a more diverse range of organisms. Reefs are often quite near to the surface, but not all definitions require this.

<span class="mw-page-title-main">Cay</span> Small island formed on the surface of a coral reef

A cay, also spelled caye or key, is a small, low-elevation, sandy island on the surface of a coral reef. Cays occur in tropical environments throughout the Pacific, Atlantic, and Indian oceans, including in the Caribbean and on the Great Barrier Reef and Belize Barrier Reef.

<span class="mw-page-title-main">Tide pool</span> Rocky pool on a seashore, separated from the sea at low tide, filled with seawater

A tide pool or rock pool is a shallow pool of seawater that forms on the rocky intertidal shore. These pools typically range from a few inches to a few feet deep and a few feet across. Many of these pools exist as separate bodies of water only at low tide, as seawater gets trapped when the tide recedes. Tides are caused by the gravitational pull of the sun and moon. A tidal cycle is usually about 25 hours and consists of one or two high tides and two low tides.

<span class="mw-page-title-main">Live rock</span> Rock from the ocean introduced into a saltwater aquarium

Live rock is rock from the ocean that has been introduced into a saltwater aquarium. Along with live sand, it confers to the closed marine system multiple benefits desired by the saltwater aquarium hobbyist. The name sometimes leads to misunderstandings, as the "live rock" itself is not actually alive, but rather is simply made from the aragonite skeletons of long dead corals, or other calcareous organisms, which in the ocean form the majority of coral reefs. When taken from the ocean it is usually encrusted with coralline algae and inhabited by a multitude of marine organisms. The many forms of micro and macroscopic marine life that live on and inside of the rock, which acts as an ideal habitat, give it the name "live rock".

<span class="mw-page-title-main">Coralline algae</span> Order of algae (Corallinales)

Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white, or gray-green. Coralline algae play an important role in the ecology of coral reefs. Sea urchins, parrot fish, and limpets and chitons feed on coralline algae. In the temperate Mediterranean Sea, coralline algae are the main builders of a typical algal reef, the Coralligène ("coralligenous"). Many are typically encrusting and rock-like, found in marine waters all over the world. Only one species lives in freshwater. Unattached specimens may form relatively smooth compact balls to warty or fruticose thalli.

Coralline means 'resembling coral' and may refer to:

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A carbonate platform is a sedimentary body which possesses topographic relief, and is composed of autochthonic calcareous deposits. Platform growth is mediated by sessile organisms whose skeletons build up the reef or by organisms which induce carbonate precipitation through their metabolism. Therefore, carbonate platforms can not grow up everywhere: they are not present in places where limiting factors to the life of reef-building organisms exist. Such limiting factors are, among others: light, water temperature, transparency and pH-Value. For example, carbonate sedimentation along the Atlantic South American coasts takes place everywhere but at the mouth of the Amazon River, because of the intense turbidity of the water there. Spectacular examples of present-day carbonate platforms are the Bahama Banks under which the platform is roughly 8 km thick, the Yucatan Peninsula which is up to 2 km thick, the Florida platform, the platform on which the Great Barrier Reef is growing, and the Maldive atolls. All these carbonate platforms and their associated reefs are confined to tropical latitudes. Today's reefs are built mainly by scleractinian corals, but in the distant past other organisms, like archaeocyatha or extinct cnidaria were important reef builders.

<span class="mw-page-title-main">Crustose</span>

Crustose is a habit of some types of algae and lichens in which the organism grows tightly appressed to a substrate, forming a biological layer. Crustose adheres very closely to the substrates at all points. Crustose is found on rocks and tree bark. Some species of marine algae of the Rhodophyta, in particular members of the order Corallinales, family Corallinaceae, subfamily Melobesioideae with cell walls containing calcium carbonate grow to great depths in the intertidal zone, forming crusts on various substrates. The substrate can be rocks throughout the intertidal zone, or, as in the case of the Corallinales, reef-building corals, and other living organisms including plants, such as mangroves and animals such as shelled molluscs. The coralline red algae are major members of coral reef communities, cementing the corals together with their crusts. Among the brown algae, the order Ralfsiales comprises two families of crustose algae.

<span class="mw-page-title-main">Rhodolith</span> Calcareous marine nodules composed of crustose red algae

Rhodoliths are colorful, unattached calcareous nodules, composed of crustose, benthic marine red algae that resemble coral. Rhodolith beds create biogenic habitat for diverse benthic communities. The rhodolithic growth habit has been attained by a number of unrelated coralline red algae, organisms that deposit calcium carbonate within their cell walls to form hard structures or nodules that resemble beds of coral.

<span class="mw-page-title-main">Bioclast</span>

Bioclasts are skeletal fossil fragments of once living marine or land organisms that are found in sedimentary rocks laid down in a marine environment—especially limestone varieties around the globe, some of which take on distinct textures and coloration from their predominate bioclasts—that geologists, archaeologists and paleontologists use to date a rock strata to a particular geological era.

In algal anatomy, a pit connection is a hole in the septum between two algal cells, and is found only in the red algae − specifically, all orders except the Porphyridiales and haploid Bangiales. They are often stoppered with proteinaceous "pit plugs". By contrast, many fungi contain septal pores − an unrelated phenomenon.

<span class="mw-page-title-main">Koko Guyot</span> Guyot in the northern Pacific Ocean

Koko Guyot is a 48.1-million-year-old guyot, a type of underwater volcano with a flat top, which lies near the southern end of the Emperor seamounts, about 200 km (124 mi) north of the "bend" in the volcanic Hawaiian-Emperor seamount chain. Pillow lava has been sampled on the north west flank of Koko Seamount, and the oldest dated lava is 40 million years old. Seismic studies indicate that it is built on a 9 km (6 mi) thick portion of the Pacific Plate. The oldest rock from the north side of Koko Seamount is dated at 52.6 and the south side of Koko at 50.4 million years ago. To the southeast of the bend is Kimmei Seamount at 47.9 million years ago and southeast of it, Daikakuji at 46.7.

<i>Scutellastra cochlear</i> Species of gastropod

Scutellastra cochlear is a species of sea snail, a marine gastropod mollusc in the family Patellidae, one of the families of true limpets. It is commonly known as the snail patella, the pear limpet or the spoon limpet and is native to South Africa. It often grows in association with the crustose coralline alga Spongites yendoi and a filamentous red alga which it cultivates in a garden. It was first described by the malacologist Ignaz von Born in 1778 as Patella cochlear.

Palaeoaplysina is a genus of tabular, calcified fossils that are a component of many Late Palaeozoic reefs. The fossil acted as a baffle to trap sediment. Historically interpreted as a sponge or hydrozoan, recent studies are converging to its classification in the coralline stem group, placing it among the red algae.

<span class="mw-page-title-main">Shell growth in estuaries</span>

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Sporolithon ptychoides is a species of crustose red seaweed with a hard, calcareous skeleton in the family Corallinaceae. It has a widespread distribution, being present in the Pacific and Indian Oceans, the Mediterranean Sea and the southwestern Atlantic Ocean.

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<span class="mw-page-title-main">Coral reefs of the Solomon Islands</span>

The Coral reefs of the Solomon Islands consists of six major islands and over 986 smaller islands, in Oceania, to the east of Papua New Guinea and northwest of Vanuatu. The Solomon Islands lie between latitudes 5° and 13°S, and longitudes 155° and 169°E. The distance between the westernmost and easternmost islands is about 1,500 km (930 mi). The Santa Cruz Islands are situated north of Vanuatu and are especially isolated at more than 200 km (120 mi) from the other islands. The Solomon Islands has the 22nd largest Exclusive Economic Zone of 1,589,477 km2 (613,701 sq mi) of the Pacific Ocean.