For instance, cold water reefs of stony corals could be found.

The evolutionary relationships among stony corals were first examined in the 19th and early 20th centuries.

There are 84 species of stony corals in Hong Kong.

Stony corals, their relatives, often grow alongside them and they too are colonial creatures.

Agariciidae is a family of reef building stony corals.

Caulastraea is a genus of stony corals in the Faviidae family.

It is inconspicuous, often growing in crevices and concealed among the branches of stony corals.

In a few stony corals, this is the primary method of feeding, and the tentacles are reduced or absent.

Many fishkeepers have found that dosing with kalkwasser benefits their hard and stony corals.

Others live inside stony corals, and may become pathogenic if the coral is stressed by rising sea temperatures.

These sea snails feed on stony corals (Scleractinia) and hydrozoans.

Stony corals may be solitary or compound.

C. novaeguineae feeds on detritus and small invertebrates, including stony corals.

In most healthy reefs, stony corals are predominant.

Cynaria is a genus of large polyp stony corals.

Some invertebrates such as mollusks or stony corals also use the calcium and strontium released.

Caryophylliina is a suborder of stony corals, order Scleractinia.

Rhodactis are related to stony corals but do not produce a stony skeleton.

Stony corals can reproduce both sexually and asexually.

Appendix 1: List of extant stony corals.

In many respects, they resemble the stony corals, except for the absence of a stony skeleton.

They will adapt to a captive diet quickly which will usually prevent them from consuming soft or stony corals.

Leather corals lack the hard calcium carbonate skeleton of stony corals.

Coral reefs are made predominantly of stony corals and supported by the limestone skeleton they excrete.

EPA's rapid bioassessment protocol for stony corals was presented along with status reports from each island.

Hard corals live only in the waters on the island's east side.

The mean cover of hard corals was also higher in sanctuary zones.

They are often found where hard corals have largely died out as a result of one of the above processes.

The starfish show preferences between the hard corals that they feed on.

It feeds primarily on the polyps of soft and hard corals.

At first it was a meadow; a moment later the man walked in a grove of hard corals, ducking beneath their branches.

Aquafauna Hard corals recorded are 174 species of 48 genera and sub-genera.

Soft corals are easier to maintain in captivity than hard corals.

The reefs are seldom visited, and contain miles of hard corals, some said to be thousands of years old.

It grows much more quickly than the traditional hard corals (Crallium spp.)

The Reunion Island coral reef is a rich habitat for both soft and hard corals.

All the inverts that you are considering are suitable over the long term, but do steer clear of hard corals.

Hard corals build a limestone skeleton so that as nearby colonies expand and grow a reef is formed.

Below: The Crown of Thorns can eat hard corals.

These can be regarded as hard corals which have, through some quirk of evolution, lost the ability to produce calcareous skeletons.

Four hundred coral species, both hard corals and soft corals inhabit the reefs.

The skeletal parts of hard corals are made of calcium carbonate and if this is in short supply they can suffer.

Hard corals belong to the subclass Zoantharia.

The reefs comprise a vast selection of soft corals and hard corals alike.

Hard corals, like the 400-year-old star, brain and boulder corals on this reef, grow one centimeter a year under the best of conditions.

Offshore reefs and waters harbor more than 200 species of fish, pelagic birds, whales and hard corals.

Cup corals are solitary hard corals which superficially resemble orange sea anemones.

Hard corals are the reef-builders, and grow their tough external skeletons by extracting nutrients from algae growing within them.

Soon we were drifting above white sand channels, which meandered through towering columns of hard corals, sponges and gorgonians.

Strontium plays an important role in marine aquatic life, especially hard corals, which use strontium to build their exoskeletons.

There are two main hypotheses about the origin of Scleractinia.

At the beginning of Scleractinia's development, four groups with different microstructure can distinguished.

This skeleton is formed of aragonite, similar to that of scleractinia.

Instead, the skeleton is primarily calcitic - a type rarely if not ever seen in extant scleractinia.

Caryophylliina is a suborder of stony corals, order Scleractinia.

There are two groups of Scleractinia:

Species richness of recent Scleractinia.

Close up, it is visibly structured, resembling a "madrepore" (stone coral, Scleractinia) colony.

The discovery and analysis of Coelosimilia has changed the previous understanding of the evolution of the Scleractinia.

They feed by night on stony corals (mainly Pocillopora species in the order Scleractinia), and resting during the day.

Hermatypic corals in the subclass Scleractinia are stony corals that build reefs.

Corals of order Scleractinia build their endoskeletons from aragonite (a polymorph of calcium carbonate).

In a colonial Scleractinia, the repeated asexual division of the polyps causes the corallites to be interconnected, thus forming the colonies.

The World Register of Marine Species lists the following families as being included in the order Scleractinia:

The names Madrepore and Madreporaria were formerly applied universally to any stony coral of the family Scleractinia.

Pocilloporidae is a family of stony corals in the order Scleractinia occurring in the Pacific and Indian Oceans.

Cnidaria / Coelenterata: Scleractinia corals --- volume in preparation)

Hermatypic genera include Scleractinia, Millepora, Tubipora and Heliopora.

Epitonium clathrum is a predator of sea anemones (Anthozoa, Actiniaria) and corals (Anthozoa, Scleractinia).

Coenothecalia (Helioporidae) have no spicules, and is the only Octocoral known to produce a massive skeleton formed of fibrocrystalline aragonite fused into lamellae, similar to that of scleractinia.

Madrepora oculata, also called zigzag coral, is a Scleractinia (stony coral) that is found worldwide outside of the polar regions, growing in deep water at depths of 80-1500 meters.

Recently discovered Paleozoic corals with aragonitic skeletons and cyclic septal insertion - two features that characterize Scleractinia - have strengthened the hypothesis for an independent origin of the Scleractinia.

Each head of coral is formed by a colony of genetically identical polyps which secrete a hard skeleton of calcium carbonate; this makes them important coral reef builders like other stony corals in the order Scleractinia.

The stromatoporoids, for example, had largely gone and the new corals had not yet learned to build reefs (in fact the Rugosa were never to remember the habit and it was only to be relearned by the Scleractinia of the Mesozoic).

Results of molecular studies explained a variety of aspects of the evolutionary biology of the Scleractinia, including connections between and within extant taxa and supplied support for hypotheses about extant corals that are founded on the fossil record.