coral marine invertebrates class typically live compact colonies identical individual group includes important reef builders inhabit tropical oceans calcium form hard skeleton coral group colony genetically identical sac like animal typically millimeters diameter centimeters length set surround central mouth opening near base generations colony creates large skeleton characteristic species individual heads grow reproduction breed sexually spawning species release simultaneously period nights moon catch small fish cells obtain majority energy nutrients genus live tissues commonly known contain require sunlight grow clear shallow water typically depths shallower metres major contributors physical structure coral reefs develop tropical subtropical waters enormous great barrier reef coast queensland australia rely live deeper water cold water genus surviving deep metres found darwin north west scotland found far north coast taxonomy aristotle classified plant animals animals characteristics plants animals plants persian classified animals arguing respond touch people believed plants eighteenth century microscope establish coral characteristic thin cell membranes animal phylogeny clearly understood number different models proposed sea coral constitute grouping united fold symmetry trait appears primitive members group presented comes study based divergence mitochondrial dna group nuclear markers classified class divided include sea groups generally fold symmetry include blue coral soft sea sea fans sea groups fold symmetry having tube dwelling fire true order known class anatomy animals class differ having stage life cycle body unit animal colonial initial produce colony gradually developing small start known hard produce skeleton composed calcium strengthen protect organism deposited living tissue connects sit cup shaped depressions skeleton known colonies coral variable appearance single species adopt plate like massive solid structure forms linked different types habitat variations light level water movement significant soft skeleton tissues presence tiny skeletal elements known calcium soft variable form colonial soft connected sheets species thick deeply embedded soft form tree like whip like central skeleton embedded tissue matrix composed protein called material soft retracted relying hard skeleton defence predators soft generally relying chemical defences form toxic substances present tissues known fold symmetry soft mouth surrounded ring cylindrical point soft branches known tropical species reduced mere fused like appearance retracted day spread night catch small organisms shallow water species soft diet products produced complex developed system canals allowing significant sharing nutrients ecology feeding feed variety small organisms microscopic small fish kill prey cells carry venom rapidly release response contact organism dormant response nearby prey touching trigger opens apparatus fires prey venom injected hollow prey manoeuvre prey mouth contract bring prey stomach prey stomach allowing elimination waste products beginning hunting cycle drifting organic molecules dissolved organic molecules groups sea form relationship class algae genus familiar pest coral reef serves valuable model organism study typically species algae provide energy coral aid tissue plant material algae benefit safe place live consume carbon dioxide waste strain algae stress coral drives algae mass known coral algae contribute coral brown coloration colors host coral green proteins increases chance surviving short term stress regain algae possibly different species later time conditions persist eventually dies reproduction reproduce sexually reproduction allows coral settle new areas sexual predominantly reproduce sexually form single sex colonies rest broadcasters broadcast spawn releasing eggs sperm water spread offspring fuse form microscopic called typically pink elliptical shape typical coral colony forms thousand larvae year overcome odds formation new colony spawning typical coral reef multiple species present spawn night essential male female meet rely environmental cues varying species species determine proper time release water cues involve temperature change lunar cycle day length possibly chemical signalling spawning form hybrids involved coral immediate cue sunset cues release spawning event visually dramatic usually clear water brooding species reef building areas high current wave action release sperm negatively sinking waiting egg carriers harbor eggs weeks spawning events occurs species release ready settle exhibit positive swimming light reach surface waters drift grow descending seek hard surface attach begin new colony exhibit positive moving sounds reef away open water high failure rates stages process millions released colony new colonies form time spawning settling usually days months grows eventually coral head growth coral head genetically identical reproduce dividing involves splitting smaller adult new grows forms body parts distance new adult grows common body colony coral anatomy oral discs producing sized ring base producing smaller division forms large original longitudinal division begins divides body effectively splitting length mouth divides new form created generate missing body parts division occurs divide parts means basal disc oral disc new separately generate missing pieces reproduction offers benefits high reproductive rate delaying replacement dead geographical distribution colony division colonies reproduce forming colonies possible mechanisms include occurs especially family colony splits colonies early developmental stages occurs single colony different substrate create new colony involves individuals broken colony storms separated individuals start new colonies reefs order meaning involved building reefs obtain energy genus require sunlight reef forming found mainly shallow water calcium form hard skeletons framework reef reef building shallow water contain deep water species living depths light penetrate form reefs harbour types shallow water coral reef including reefs barrier reefs occur tropical subtropical seas slow growing adding height year great barrier reef thought laid million years ago time fragment die sand rubble shells decay form gradually evolving calcium structure coral reefs extremely diverse marine ecosystems hosting species fish massive numbers crustaceans animals evolutionary history appeared period million years ago fossils extremely rare period million years later widespread contained numerous occur periods form low branching masses alongside numbers began decline middle period extinct end period million years ago horn dominant middle period extinct early period existed solitary colonial forms composed filled niche vacated extinct species fossils found small numbers rocks period common later periods skeletons composed form calcium known younger skeletons readily preserved fossil record accordingly complete certain times geological past abundant like modern ancestors built reefs ended great structures rocks fossils fellow reef algae remains appear coral fossils makes useful index fossils coral fossils restricted reef remnants solitary fossils found occurs england clay formation status threats coral reefs stress world particular coral mining agricultural urban runoff pollution organic blast fishing disease digging canals access islands bays localized threats coral ecosystems broader threats sea temperature rise sea level rise changes ocean associated greenhouse gas emissions world reefs died result increased water temperature approximately world coral reefs dead world reefs risk human related activities threat reef health particularly strong southeast_asia reefs endangered world coral reefs destroyed result nations protect environmental laws caribbean tropical pacific direct contact common coral causes death coral transfer algae given adequate nutrients limited grazing water temperature changes changes kill species coral environmental stresses expel coral tissues reveal white skeletons event known coral submarine springs found coast mexico yucatán_peninsula produce water naturally low relatively high providing conditions similar expected widespread oceans absorb carbon dioxide surveys discovered multiple species live coral appeared tolerate colonies small distributed formed structurally complex reefs compose nearby protection marine protected areas reserves marine parks national monuments world heritage status fishery management habitat protection protect reefs damage governments prohibit removal coral reefs inform coastal residents reef protection ecology local action habitat restoration protection reduce local damage longer term threats temperature change sea level rise remain challenge eliminate destruction indigenous regions projects started grow non tropical countries relation humans local economies near major coral reefs benefit abundance fish marine creatures food source reefs provide recreational diving tourism activities damage coral international projects encourage dive centres follow code conduct proven risks live coral highly sought soft easier maintain captivity hard jewelry colors appeal jewelry intensely red coral prized called fire coral fire coral red coral rare medicine medicine chemical compounds cancer aids pain uses coral skeletons bone humans coral known sanskrit widely traditional system indian medicine supplement treatment variety bone disorders associated calcium construction coral reefs places east african coast source building material ancient fossil coral limestone notably including hills oxford england building stone seen oldest buildings city including saxon tower walls city climate research annual growth bands deep sea bamboo signs effects ocean marine life growth rings allow construct year year form dating high resolution records past climatic environmental changes techniques certain species form communities called colonies dead water line perimeter submerged alive average tide level limits height analyzing growth offer low resolution record sea level change dated dating methods help reconstruct sea levels increasing sea temperatures tropical regions degree century caused major coral death coral populations able adapt uncertain evolutionary process happen quickly prevent major reduction numbers coral large sexually populations evolution slowed abundant reproduction gene flow variable coral species according coral species gene flow counted source adaptation stationary organisms coral longevity factor adaptation climate changes demonstrated cases usually shift coral shifts frequencies progressed tolerant types scientists found certain common sea temperature high able tolerate warmer water slowly implying evolutionary trade gulf_of_mexico sea temperatures rising cold sensitive coral shifted location specific species shown shift certain growth rate favorable selection slower growing heat tolerant common changes temperature complex reefs current shadows represent location help adjust environment eventually temperatures rise quickly locations separation populations climatic barriers causes realized niche shrink greatly comparison old fundamental niche shallow colonial organisms integrate trace elements skeletal structures grow structures represent functions temperature oxygen composition analysis help climate modeling calcium ratio time attributed coral calcium sea surface temperature data collected oxygen comparison coral calcium sea surface temperature data recorded time coral calcium variations confirm accuracy annual relationship variations association annual coral growth rings confirms age conversion established blending data growth rings stable data directly related climate fluctuations influence coral ratio local variations associated position convergence zone modeling sea surface temperature sea surface global moisture budget primarily influenced tropical sea surface temperatures position unique meteorological feature positioned southwestern called contains perennial position warm periods orientation extending equator south fiji french islands east south_america affecting tropical regions analysis skeletal coral linked sea surface sea surface temperature data tropical oceans ratio phenomenon related variations sea surface sea surface temperature help model tropical climate activities limited climate research current species climate research live coral species limited studied species studying coral provides stable foundation interpretations simpler physically extract data comparison species complexity species skeletal structure creates difficulty physically sampled happens living coral records coral modeling hobby increasingly expanded recent years include reef tanks fish tanks include large amounts live rock coral allowed grow spread tanks kept natural like state algae form algae deep sand bed providing tanks rock kept largely bare algae normally order appear neat clean popular kind coral kept soft coral especially mushroom especially easy grow wide variety conditions originate enclosed parts reefs water conditions vary lighting reliable direct small coral open brightly lit reef conditions demanding large coral sort compromise coral known coral farming coral cultivation commercial purposes coral reef restoration showing promise potentially effective tool restoring coral reefs declining world process bypasses early growth stages risk dying coral fragments known seeds grown reef coral farmed coral farmers live locally reefs farm reef conservation income farmed scientists research businesses supply live ornamental coral trade private gallery images category coral reefs category coral
Coral