Symbiotic relationship in the great barrier reef

Coral calls for help and fish respond – The Fisheries Blog

symbiotic relationship in the great barrier reef

Rachel Karsten. Updated 26 March Transcript. It is still a symbiotic relationship if only one living thing benefits. Corals provide essential habitat structure and energy in coral reef systems, facilitating the existence of numerous reef associated species. Indo-Pacific coral . Read about commensalistic and mutualistic relationships on the reef. Individual coral colonies, especially branching corals, can easily be toppled in high-energy reef They get whatever additional nutrition they need from symbiotic algae, such as zooxanthellae, perform a great cleanup service as they get a meal.

Coral under siege by the seaweed Chlorodesmis fastigiata. While there are a number of reasons for these losses pollution and ocean acidification and warmingremoval of herbivorous fish through overfishing either through directly removing these species or through trophic cascades is one that is commonly overlooked.

Green seaweed that has taken over a large portion of the Great Barrier Reef in Australia. Researcher Dixson and Hay recently found that this mutualistic relationship is even more interesting than we originally thought. A juvenile Gobidon fish is shown on an Acropora coral.

symbiotic relationship in the great barrier reef

These fish spend their entire lives with the same coral, and protect the coral from encroaching seaweed. Joao Paulo Krajewski source: 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.

Symbiotic Relationships in Coral Reefs | Sciencing

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.

symbiotic relationship in the great barrier reef

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.

symbiotic relationship in the great barrier reef

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.

symbiotic relationship in the great barrier reef

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. But the clownfish and anemone are a predatory team, working side by side and sharing food. In addition, the clownfish fight off intruders, such as anemone-eating butterflyfish, and the stinging cells nematocysts of the anemone deter potential clownfish predators.

Many reef animals that can't groom themselves, like the reef lizardfish Synodus variegatushave evolved to secrete a mucus coating. The mucus offers some protection against parasites and also reduces drag as they swim. Unfortunately, mucus itself is an attractive food to some parasites and bacteria.

What's a lizardfish to do? It visits a small cleaner fish, like the bluestreak wrasse, that gently eats away surface parasites from skin, mouth, and gills. The resident fish doctor and dentist on the reef is the bluestreak cleaner wrasse Labroides dimidiatus. With an easily identifiable bright blue stripe and stereotypical behavior, the bluestreak attracts larger fish, like the reef lizardfish, to its cleaning station.

As it makes a meal out of the larger fish's parasites, the bluestreak gently tickles its customers, a behavior that seems to bring them back again and again. Sponge crabs Dromiidae family avoid predators by carrying a disguise with them at all times. Their posterior legs are modified for grasping, and the crabs use them to carry live Halichondria sponges on their backs. Since the sponges are toxic to most potential predators, the undercover crab doesn't have to worry about being attacked and can concentrate on more important things, like finding food.


Many sea sponges have evolved chemical weaponry for use against other sessile organisms in the never-ending battle for space on the reef. Since the compounds tend to be distasteful and often toxic to predators, the sponges avoid most predation. Sponge crabs exploit this defense by carrying live sea sponges on their backs. And the sponges may benefit, too: By living atop a crab, they no longer have to battle for space.

Myths about divers being caught and eaten by giant clams Tridacna gigas still abound. This is a mutual symbiotic relationship that is beneficially to both participants. Using the coral skeleton as a place to anchor, these sessile, or stationary, organisms provide shelter for fish shrimp, crabs and other small animals.

Coral calls for help and fish respond

In both cases, the symbiosis is commensal. 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.

symbiotic relationship in the great barrier reef

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.