Corals Sentence Examples

They contain corals, but are not coral reefs.

The corals are few in number, but the Molluscoida (Polyzoa) are more numerous in species and individuals.

Corals, both reef-builders and others, flourished in the clearer waters; rugose forms are represented by Amplexoid, Zaphrentid and Cyathophyllid types, and by Lithostrotion and Phillipsastraea; common tabulate forms are Chaetetes, Chladochonus, Michelinia, &c. Amongst the echinoderms crinoids were the most numerous individually, dense submarine thickets of the long-stemmed kinds appear to have flourished in many places where their remains consolidated into thick beds of rock; prominent genera are Cyathocrinus, Woodocrinus, Actinocrinus; sea-urchins, Archaeocidaris, Palaeechinus, &c., were present; while the curious extinct Blastoids, which included the groups of Pentremitidae and Codasteridae, attained their maximum development.

The later beds of the island belong to the Jurassic, Cretaceous and Tertiary systems. At the western foot of the Ida massif calcareous beds with corals, brachiopods (Rhvnchonella inconstans, &c.) have been found, the fossils indicating the horizon of the Kimmeridge clay.

Corals would now grow luxuriantly in these shallow coastal waters of increasing temperature, forming reefs and extensive coral flats.

Japan is not rich in corals and sponges.

Waves and tidal currents produce their full effects in that region, and in high latitudes the effect of transport of materials by ice is very important; while in the warm water of the tropics the reefbuilding animals and plants (corals and calcareous algae) carry on their work most effectively there.

When the proportion of calcium carbonate in the blue mud is considerable there results a calcareous ooze, which when found on the continental slope and in enclosed seas is largely composed of remains of deep-sea corals and bottom-living foraminif era, pelagic organisms including pteropods being less frequently represented.

North America is bathed in frigid waters around its broad northern shores; its mountains bear huge glaciers in the north-west; the outlying area of Greenland in the north-east is shrouded with ice; and in geologically recent times a vast ice-sheet has spread over its north-eastern third; while warm waters bring corals to its southern shores.

South America has warm waters and corals on the north-east, and cold waters and glaciers only on its narrowing southern end.

The Hydrozoa are thus shown to belong to the group of Coelenterata Cnidaria, and it remains to consider more fully their distinctive features, and in particular those which mark them off from the other main division of the Cnidaria, the Anthozoa, comprising the corals and sea-anemones.

Here the broad distinction has been drawn between volcanic and coral islands; but this requires amplification, both because the coral islands follow more than one type, and because the work of corals is in many cases associated with the volcanic islands in the form of fringing or barrier reefs.

The departure of the Ordovician life from that of the Cambrian was perhaps most pronounced in the great development of the molluscs and crinoids (including cystoids), but corals were also abundant for the first time, and graptolites came into prominence.

Corals, echinoderms, brachiopods and all groups of molluscs abounded.

Among the more important features of the marine life of the period were (1) the great development of the molluscs, especially of cephalopods; (2) theabundanceoflargebrachiopods; (3) theaberrant tendencies of the trilobites; (4) the profusion of corals; and (5) the abundance, size and peculiar forms of the fishes.

Fossil corals fix the geological age of the rock.

The groups of organisms utilized for zoning and correlation by different workers include brachiopods, pelecypods, cephalopods, corals, fishes and plants; and the results of the comparison of the faunas and floras of different areas where Carboniferous rocks occur are generalized in the table below.

The old land area still existed to the north, but doubtless much reduced in height; against this land, detrital deposits still continued to be formed, as in Scotland; while over central Ireland and central and northern England the clearer waters of the sea furnished a suitable home for countless corals, brachiopods and foraminifera and great beds of sea lilies; sponges flourished in many parts of the sea, and their remains contributed largely to the formation of the beds of chert.

The abundance of corals in some of the Carboniferous seas and possibly also the large size of some of the Productids and foraminifera may be taken as evidence of warm or temperate waters.

Corals, Archaeocyathus, Spirocyathus, &c., lived in the Cambrian seas along with starfishes (Palaeasterina), Cystideans, Protocystiles, Trochocystites and possibly Crinoids, Dendrocrinus.

In the subdivision Anthozoa, comprising the sea-anemones and corals, the individual is always a polyp; in the Hydrozoa, however, the individual may be either a polyp or a medusa.

The reef-building corals are polyp-colonies, strengthened by the formation of a firm skeleton.

Although corals have been familiar objects since the days of antiquity, and the variety known as the precious red coral has been for a long time an article of commerce in the Mediterranean, it was only in the 18th century that their true nature and structure came to be understood.

The structure and classification of polyps, however, were at that time very imperfectly understood, and it was fully a century before the true anatomical characters and systematic position of corals were placed on a secure basis.

This gives off new outgrowths, and these, branching and anastomosing with one another, may form a network, adhering to stones, corals, or other objects, from which FIG.

All recent corals, as has already been said, conform so closely to the anatomy of normal Actinians that they cannot be classified apart from them, except that they are distinguished by the possession of a calcareous skeleton.

The septa in recent corals always bear a definite relation to the mesenteries, being found either in every entocoele or in every entocoele and exocoele.

The larvae of corals are free swimming ciliated forms known as planulae, and they do not acquire a corallum until they fix themselves.

In others the peripheral ends of the septa are united only by bars or trabeculae, so that the theca is perforate, and in many such perforate corals the septa themselves are pierced by numerous perforations.

A large number of corals, both aporose and perforate, are colonial.

In division a vertical constriction divides a zooid into two equal or unequal parts, and the several parts of the two corals thus produced are severally derived from the corresponding parts of the dividing corallum.

In colonial corals a bud is always formed from the edge-zone, and this bud develops into a new zooid with its corallum.

Corals have been divided into A porosa and Perforata, according as the theca and septa are compact and solid, or are perforated by pores containing canals lined by endoderm.

Various attempts have been made to classify corals according to the arrangement of the septa, the characters of the theca, the microscopic structure of the corallurn, and the anatomy of the soft parts.

The lastnamed method has proved little more than that there is a remarkable similarity between the zooids of all recent corals, the differences which have been brought to light being for the most part secondary and valueless for classificatory purposes.

On the other hand, the study of the anatomy and development of the zooids has thrown much light upon the manner in which the corallum is formed, and it is now possible to infer the structure of the soft parts from a microscopical examination of the septa, theca, &c., with the result that unexpected relationships have been shown to exist between corals previously supposed to stand far apart.

This has been particularly the case with the group of Palaeozoic corals formerly classed together as Rugosa.

Stylaster has cyclosystems. In Allopora the cyclostems resemble the calyces of Anthozoan corals.

Pedicularia, attached to corals.

Shell irregular; radula absent; foot and siphon short; sedentary animals, living in corals.

Many of the elements such as copper, lead, zinc, nickel, cobalt and manganese have only been found in the substance of sea-weeds and corals.

In many secondary corals (Cyclolites, Thamnastraea) the trabeculae are so far separate that the individual bars are easily recognizable, and each looks something like a bamboo owing to the thickening of the two ends of each node.

The septa of modern perforate corals are shown to have a structure nearly identical with that of the secondary forms, but the trabeculae and their nodes are only apparent on microscopical examination.

The aporose corals, too, have a practically identical structure, their compactness being due to the union of the trabeculae throughout their entire lengths instead of at intervals, as in the Perforata.

Further, the trabeculae may be evenly spaced throughout the septum, or may be grouped together, and this feature is probably of value in estimating the affinities of corals.

The Scleractiniae may best be divided into groups of families which appear to be most closely related to one another, but it should not be forgotten that there is great reason to believe that many if not most of the extinct corals must have differed from modern Actiniidea in mesenterial characters, and may have only possessed Edwardsian mesenteries, or even have possessed only four mesenteries, in this respect showing close affinities to the Stauromedusae.

Moreover, there are some modern corals in which the secondary cycle of mesenteries departs from the Actinian plan.

Beyond their general utility and value as sources of lime, few of the corals present any special feature of industrial importance, excepting the red or precious coral (Corallium rubrum) of the Mediterranean Sea.

Huxley's Actinozoa comprised the sea-anemones, corals and sea-pens, on the one hand, and the Ctenophora on the other.

The drop off is over 40m but the walls are covered in sponges, anemones, soft corals and black coral.

This book is essential reading for any marine aquarist wishing to keep tropical corals.

We specialize in marine fish, corals & invertebrates ideal for reef aquarium set ups.

Andy Miller Sipidan Island barracuda Point Tornado of 1000's of schooling barracudas, taking your mind off the fantastic healthy corals.

Corals are one of the world's biggest on line sports bookmakers offering fixed odds betting on the world's major sporting events.

These rocks demonstrate a change from coastal to marine conditions and contain fossil brachiopods, corals and the remains of sea-lilies.

Plenty of excellent corals can be found, brachiopods, bivalves and Trilobites.

Most modern reefs are built by corals and algae, but sponges, bryozoans and bivalves have all formed reefs in the geological past.

It is an ideal food for all filter feeders such as Fan worms, sponges soft corals and many more.

Some of the huge gorgonian fan corals are more than 3m high.

There were also a myriad of soft corals of all colors from red to yellow to purple.

Deep-water corals such as Lophelia pertusa live in the cold, dark waters of the Atlantic, the Darwin Mounds are 1,000 meters down.

In addition to encouraging unwanted algae growth, phosphates slow the skeletal growth of stony corals.

What you will not find here are pristine corals.

At about 7 meters the reef appeared colorful with large fields of staghorn corals.

Their main research interests are color vision and color perception in marine animals and stress in reef-building corals due to climate change respectively.

The wreck diver may get bored with endless soft corals however beautiful they are.

The wreck is very popular with photographers as it is totally encrusted in anemone, gorgonians and corals.

Many corals have a hard exoskeleton made of calcium carbonate.

Fusiliers hover in shoals just off the reef, and butterfly fish flit between the corals.

It's an 80-90 foot drift or anchor dive among large sponges, gorgonians, and corals.

Just outside look for Spur and Grove formations - narrow canyons of corals are great for spotting grouper and the occassionally eel.

The reefs are composed of finger corals and brain corals covered with colorful sponges, hydroids, sea whips and sea fans.

Black Coral This site is littered with peppered morays which peer out from soft corals.

Check the ropes carefully for large sea horses (Hippocampus kuda ). Also many soft corals, schooling fish, lionfish, giant morays.

A good clue for a horse mussel bed is abundant soft corals on sediment where they wouldn't normally be.

Among the rocks, you'll find groups of plumose anemones, Devonshire cup corals, tubeworms and maybe a sea lemon nudibranch.

Pigmy seahorses on a red gorgonian and a forest of amazing corals.

Underwater you'll find plenty of anemones, Ross corals and edible sea urchins.

Watch out for the fire corals in shallow water these creamy tan or mustard colored corals can give a nasty sting.

We saw lots of marine life including tarpon, soft corals, rays and lots of big fish.

We managed to find some Crinoids, Corals and Shells but unfortunately found no trilobites which are much more rare.

On the bow of the wreck, we saw a hawksbill turtle feeding on the soft corals.

Its deck is comprehensively encrusted with sponges and corals, and patrolled by giant Maori wrasse and jacks.

Thus, about 1875, the distinction of Echinoderms from such radiate animals as jelly-fish and corals (see Coelentera), by their possession of a body-cavity ("coelom") distinct from the gut, was fully realized; while their severance from the worms (especially Gephyrea), with which some Echinoderms were long confused, had been necessitated by the recognition in all of a radial symmetry, impressed on the original bilateral symmetry of the larva through the growth of a special division of the coelom, known as the "hydrocoel," and giving rise to a set of water-bearing canals - the watervascular or ambulacral system.

De Blainville included in his group many unicellular forms such as Noctiluca (see PROTOZOA), sea-anemones, corals, jelly-fish and hydroid polyps, echinoderms, polyzoa and rotifera.

It contains almost everything required for growth by corals and the beautiful encrusting pink and red coralline algae.

In this clay can be found rugose corals and spiky trilobites.

Giant trilobites, brachiopods and corals are common in the sea.

Previously never dived before, this site had pristine hard corals, large schools of unicorn fish, as well as inqusitive sharks.

The Southwest color themes of corals and aquas were very popular color choices and still are today.

Don't limit yourself to matte corals, but rather try an iridescent gloss or nail polish that will give you a fun new look without being completely obvious.

You may want to choose candles in colors of the ocean, like blue, green, teals, tans or corals.

Corals and other quick-growing cal- careous marine organisms are the most powerful in this respect by creating new land in the ocean.

Nemertines live in the sea, some being common amongst the corals and algae, others hiding in the muddy or sandy bottom, and secreting gelatinous tubes which ensheath the body along its whole length.

They are ridges of aeolian limestone plastered over by a thin layer of corals and other calcareous organisms. The very remarkable "serpuline atolls" are covered by a solid crust made of the convoluted tubes of serpulae and Vermetus, together with barnacles, mussels, nullipores, corallines and some true incrusting corals.

In the animal kingdom it occurs as both calcite and aragonite in the tests of the foraminifera, echinoderms, brachiopoda, and mollusca; also in the skeletons of sponges and corals.

The Hydrozoa comprise the hydroids, so abundant on all shores, most of which resemble vegetable organisms to the unassisted eye; the hydrocorallines, which, as their name implies, have a massive stony skeleton and resemble corals; the jelly-fishes so called; and the Siphonophora, of which the species best known by repute is the so-called "Portuguese man-of-war" (Physalia), dreaded by sailors on account of its terrible stinging powers.

The Mollusca agree in being coelomate with the phyla Vertebrata, Platyhelmia (flat-worms), Echinoderma, Appendiculata (insects, ringed-worms, &c.), and others - in fact, with all the Metazoa except the sponges, corals, polyps, and medusae.

Neomenia and its allies are marine animals living at depths of 15 to Boo fathoms on soft muddy ground; they are found crawling on corals and hydrozoa, on which they feed.

Formerly all corals in which tabulae are present were classed together as Tabulata, but Tubipora is an undoubted Alcyonarian with a lamellar stolon, and the structure of the fossil genus Syringopora, which has vertical corallites united by horizontal solenia, clearly shows its affinity to Tubipora.

The cavities both of the calices and coenenchymal tubes of Heliopora are closed below by horizontal partitions or tabulae, hence the genus was formerly included in the group Tabulata, and was supposed to belong to the madreporarian corals, both because of its lamellar skeleton, which resembles that of a Ma.drepore, and because each calicle has from twelve to fifteen radial partitions or septa projecting into its cavity.

The structure of the zooid of Heliopora, however, is that of a typical Alcyonarian, and the septa have only a resemblance to, but no real homology with, the similarly named structures in madreporarian corals.

As far as the anatomy of the zooid is concerned, the majority of the stony or madreporarian corals agree exactly with the soft-bodied Actinians, such as Actinia equina, both in the number and arrange 4 4 ¢ 2 4 FIG.

The remaining forms, the Actiniidea, are divisible into the Malacactiniae, or soft-bodied sea-anemones, which have !already been described sufficiently in the course of this article, and the Scleractiniae (= Madreporaria) or true corals.

Hence in corals in which there is only a single cycle of mesenteries the septa are correspondingly few in number; where several cycles of mesenteries are present the septa are correspondingly numerous.

In some corals, in which all the septa are entocoelic, each new system is embraced by a mesenteric couple; in others,in which the septa are both entocoelic and exocoelic, three septa are formed in Il FIG.

In some corals the septa are solid imperforate plates of calcite, and their peripheral ends are either firmly welded together, or are united by interstitial pieces so as to form imperforate theca.

In many of these so-called rugose forms the septa have a characteristic arrangement, differing from that of recent corals chiefly in the fact that they show a tetrameral instead of a hexameral symmetry.

As the microscopic character of the corallum of these extinct forms agrees with that of recent corals, it may be assumed that the anatomy of the soft parts also was similar, and the tetrameral arrange ment, when present, may obviously be referred to a stage when only the first two pairs of Edwardsian mesenteries were present and septa were formed in the intervals between them.

Space forbids a discussion of the proposals to classify corals after the minute structure of their coralla, but it will suffice to say that it has been shown that the septa of all corals are built up of a number of curved bars called trabeculae, each of which is composed of a number of nodes.

There are a few reds, plenty of pinks, some nudes, several corals and plenty of eclectic purples, blues and yellows in the mix.