Algae and the Reef, Belize Barrier Reef
Coral reef ecosystems are teeming with symbiotic relationships. Inside each coral polyp lives a single-celled algae called zooxanthellae. A new study shows that the relationship between coral polyps and zooxanthellae In that symbiotic relationship, the algae get a protected place to live and in According to a press release from Saudi Arabia's King Abdullah. It needs to create a symbiotic relationship with algae to survive. The only time when coral does not have an algae symbiont is during the.
Fast swimmers, they easily catch up with a host and attach from below, using a powerful suction disc -- which evolved from an ordinary dorsal fin -- on top of their heads. The remoras' streamlined shape allows them to hitchhike without slowing down their hosts. It takes a lot of energy to secrete the calcium carbonate exoskeletons hard outer structures that make up coral reefs.
Evolution: Survival: Coral Reef Connections
Reef waters are typically very low in nutrients, so most coral animals can't filter out enough food to provide the extra energy they need. To make up for this deficiency, hermatypic corals shelter microscopic algae zooxanthellae within their tissues; in exchange, the algae supply the corals with carbohydrates so the corals have enough energy to build reefs.
Zooxanthellae pronounced "zoe-zan-thelly" are microscopic algae that live within the tissues of host animals, including hermatypic coral animals.
Like all plants, zooxanthellae make their own food by a process called photosynthesis.
When corals met algae: Symbiotic relationship crucial to reef survival dates to the Triassic
Using solar energy absorbed by special pigments, they transform carbon dioxide into carbohydrates and oxygen. What they don't need themselves passes directly into the coral's gut cavity, providing the extra energy the coral needs to produce a calcium carbonate exoskeleton. Some multicellular algae on the reef produce calcium carbonate limestone skeletons very similar to those made by hard corals. These calcareous algae play a major role in barrier reef construction, acting as a sort of living mortar that holds together individual coral colonies.
Growing between corals and wrapping around the bases of branching corals, calcareous algae protect the corals from erosion, especially in high-energy areas. Individual coral colonies, especially branching corals, can easily be toppled in high-energy reef zones, such as the reef front and rock rim. Waves can easily scour away sediments from a colony's base, uprooting it and pushing it along like tumbleweed.
So how do branching corals ever get a solid foothold in such zones? Calcareous algae grow between corals and around their bases, preventing erosion and stabilizing the reef structure.
On the reef, carnivores have diversified into many more species than have herbivores. Competition among carnivores has produced a treacherous environment for prey, in which hungry jaws lurk around every corner, during all hours of the day. To escape predation, some relatively defenseless herbivores, such as parrotfish Scarus spp. Goldlined rabbitfish Siganus lineatuslocally called spine-feet fish, are so named for the defensive venomous spines at the ends of each of their pelvic fins.
But spines are a last-ditch defense. To avoid being thrust into a risky spine-to-fang battle, rabbitfish employ their expert color-changing talents to avoid predator detection in the first place. Schools of rabbitfish thus provide an excellent refuge for their poorly defended relatives, the parrotfish. Nestling among the venomous stinging tentacles of a sea anemone seems like a very bad survival strategy -- unless you and the anemone have some kind of an arrangement.
Clown anemonefish Amphiprion akindynos and sea anemones have evolved just such a relationship. As juveniles, clownfish perform a ritual of "anemone rubbing. From then on, they defend each other, and clownfish have even been seen dragging food to their host anemone.
Reef animals are masters of disguise, and sea anemones are no exception. Attached to the reef by a suction disc, tentacles swaying with the current, they are the animals perhaps most often mistaken as plants.
The illusion is further reinforced by the presence of two or more commensal clownfish among the tentacles. Sciencing Video Vault Sea anemones are also common sessile residents of coral reef.
Sea anemones are known for their mutually beneficial symbiotic relationships with clown fish and anemone fish. The tentacles of the anemones provide protection for the fish and their eggs while the anemone fish protects the anemone from predators such as the butterfly fish. They may also remove parasites from the anemone's tentacles.
Crown-of-thorns sea stars are well-known predators of coral reefs and have been known to devastate entire coral reef colonies. This is a parasitic relationship in that the sea stars find food in the polyps of the coral whereas the coral is stripped down to its skeleton and left to die. Reef Brief is a weekly column published in the San Pedro Sun Of multicellular algae, the two main types are coralline and calcareous. Coralline algae are plants that contain calcium carbonate in their tissue, made up of masses of fine thread-like filaments that spread out over the reef rock surface.
The encrusting filaments trap sediments of sand, as well as cement the particles of sand together. In this way, coralline algae strengthen and support the coral reef structure. Even after a storm hits and many coral colonies have been broken, coralline algae quickly bind the pieces back together.
Unlike the encrusting quality of coralline algae, calcareous algae, on the other hand, tend to grow upright. They too produce calcium carbonate limestone and a unique quality of this type of algae is that when the algae dies, sand from the limestone is produced.
As a result, about fifty percent of the sand found on our beaches is created. Algae is not only important to coral reefs; as a primary producer in the food chain, many fish depend on it as well.