Coral reefs are some of the most stunning and diverse natural ecosystems on the planet, supporting thousands of animals.
Coral may resemble plants, but they’re actually Cnidarian animals (commonly known as jellyfish and sea anemones). Coral polyps possess stinging cells which spear floating plants and plankton at nighttime for food collection, according to Shedd Aquarium.
1. They’re animals
Coral reefs are breathtaking and vibrant ecosystems, yet defy categorical classification. While not botanical in origin, coral reefs play an integral part in maintaining global health.
Coral reefs are made up of colonies of tiny animals called polyps that assemble their own calcium carbonate skeletons like stones. Coral belongs to the Cnidaria kingdom, along with jellyfish, anemones and sea anemones. Coral colonies live together with stinging tentacles that catch food while simultaneously protecting themselves from predators.
Polyp bodies resemble cylindrical shapes with one end bearing its mouth and arm-like tentacles enclosing it, with many tentacles equipped with thousands of stinging cells (cnidocytes) which are capable of spearing prey such as zooplankton, small fish or anything that threatens them – as well as firing spring-loaded toxic barbs which stun or kill prey before it can be consumed by their host polyp.
Coral polyps derive their energy not only from eating their own skeletons but also through an intricate relationship with algae living inside their bodies, known as zooxanthellae, that harness the sun’s photosynthesis energy and supply sugar that supplies energy to their polyps. While some coral species can survive without this relationship in colder waters, most depend on them in order to thrive.
Coral reproduces sexually by simultaneously releasing both sperm and eggs overnight during full moon periods to form planulae that settle in the water to form new colonies. Their colorful beauty has inspired humans to spend billions every year diving, snorkeling, or otherwise exploring these vast underwater forests – though their complexity far surpasses that of what media reports portray as easily.
2. They’re a source of food
Coral reefs are home to an abundance of fish species. Their shimmering beauty and bustling life have long captivated humans; yet many remain unaware that corals are animals that feed off of algae and planktonic, feeding off of plankton drifting by. A coral reef actually comprises multiple organisms living together harmoniously: hard coral polyps, microscopic algae and other creatures working in unison to provide both food and shelter for other life forms in its ecosystem.
Corals are invertebrates, like jellyfish and sea anemones, belonging to the invertebrate group. Corals share similar structures: a simple stomach with one mouth opening surrounded by tentacles stinging with stinging tentacles; many corals live together as colonies composed of hundreds to thousands of genetically identical polyps that come together and form colonies; these reproduction mechanisms include both asexual reproduction (where new polyps grow off parent ones), as well as sexual reproduction by splitting into two polyps. Shed Aquarium details how these corals reproduce: both methods (with new polyps forming off ends of parent ones) as well as sexual reproduction (when two polyps split apart).
Coral polyps use their stinging cells like harpoons to spear floating plants and small fish before digesting their meal via their mouths and stomachs. Furthermore, coral reefs serve as bustling cities of the ocean by providing homes for 25% of all marine species – providing 25 of them a home!
Reef ecosystems are highly diverse, varying depending on factors like temperature, depth and salinity of water; presence of large predators; light availability; etc. In Raja Ampat in Philippines alone there have been over 7,000 different fish identified; some can be highly colorful while others require active search to be discovered. Scientists have even identified several subterranean environments as having submerged reefs!
3. They’re a habitat
Coral reefs provide habitat to hundreds of marine organisms. Their brilliant colors are created by tiny organisms known as zooxanthellae that live symbiotically within coral tissue and release pigments which give coral its vibrant hues. Coral reefs also serve as important homes for seahorses, manta rays and more!
Although corals resemble plants, they are actually animals closely related to jellyfish and sea anemones. Corals have multicellular structures with digestive organs inside that consume other organisms for sustenance; can reproduce both sexually and asexually, as well as colonization where many individual coral polyps join forces into one large community.
Coral reefs thrive in shallow, clean ocean waters with warm temperatures; however, they can also be found worldwide (some species even reach as far north as the Arctic!).
Coral polyps are sac-like animals that resemble an open can with tentacles attached. Tentacles contain stinging cells to capture small organisms before intaking them as food sources for digestion and reproduction, plus have their own distinctive mineral skeleton that gives their color and texture.
Coral can reproduce both sexually and asexually through budding, which involves breaking off polyps from their parent colonies to form new colonies, as well as sexually through broadcast spawning – when coral polyps release eggs and sperm into the water for fertilization by ocean currents; fertilized eggs then migrate by currents to existing coral colonies or hard surfaces, where they develop into larvae.
4. They’re a source of oxygen
Coral reefs provide more than a beautiful underwater rainbow of colors; they also play a critical role in ecosystem services. Home to over 25% of marine species, coral reefs provide coastal protection from erosion and tsunamis while acting as natural water filtration systems and producing more oxygen than any other marine plant.
Coral may appear like colorful plants, but they’re actually invertebrates belonging to the Cnidaria phylum – along with jellyfish and sea anemones. Corals are colonial animals – meaning that they form colonies from groups of individual creatures called polyps that act together as one unit forming coral reefs.
Reef-building corals get their plant component from microscopic algae known as zooxanthellae that live inside their inner tissues, using sunlight to photosynthesize and provide up to 90% of their energy needs. Furthermore, these algae recycle phosphorus and nitrogen nutrients back into polyps in exchange for sugars – another energy source.
Coral polyps have simple body structures consisting of mouth and tentacles. Their tentacles are used to capture passing planktonic cells or fish which they digest with their stomachs. Their protective limestone exoskeleton is created from seawater ions they drink; over time these skeletons fuse to form large coral reefs.
Coral reefs’ density allows them to reflect some of the sun’s heat away from deeper waters where coral species need to survive, thus helping regulate our planet’s climate. Furthermore, reefs provide valuable fishing habitats and are an attractive tourist attraction.
5. They’re a source of carbon dioxide
Coral reefs play an essential role in ocean ecosystems, but they’re also natural carbon dioxide reservoirs. Corals absorb CO2 released when fossil fuels are burned or people breathe it in; that CO2 goes back into the atmosphere to warm it further and lead to climate change; as warmer water warms further still it reduces oxygen levels further reducing coral growth sluggishly which limits food supplies for growth — one reason reefs worldwide are in such trouble.
Reef-building hard corals are superorganisms composed of millions of sea anemone-like polyps. Each coral polyp has a simple body structure with mouth, body sac and tentacles for food collection; thousands of stinging cells on its tentacles react when they detect tiny fish, plankton or other food particles floating by. Stunting cells fire when these tiny prey are detected before being digested by its mouth.
Many corals rely heavily on their relationship with algae for sustenance. Zooxanthellae algae reside within their inner tissues and use light energy for photosynthesis – the process by which plants produce energy from carbon dioxide and water through photosynthesis. They supply carbon dioxide, oxygen and vital nutrients such as glucose, glycerol and amino acids – as well as providing much-needed carbon storage capacity to the coral itself.
Coral reefs rely heavily on their interactions with algae and marine life for survival, and make our planet more habitable for humans alike. Unfortunately, we’re slowly destroying these extraordinary ecosystems – and without immediate action taken now we risk losing corals along with all their benefits.