Finding gobies helps corals resist toxic algae

Living among coral branches, Gobiodon histrio will react with a chemical signal released from the coral, when the coral comes into contact with a brilliant green toxic algae and bites the invading foliage. encroachment.

When an assassin of seaweed touches a fluffy coral, the coral will release a chemical that will attract small fish 'inhabitants' to rescue.

Uncontrolled, marine algae can destroy a coral reef, marine ecologist Mark Hay of Georgia Technology Research Institute, Altalta said. But within 15 minutes of contact with poisonous seaweed, the Acropora nasuta coral released a compound that promotes goby and biting the seaweed, Hay and colleague Danielle Dixson reported in Science on November 9. .

"We have lost about 80% of living coral in the Caribbean and 50% in the Western Pacific , " said Nancy Knowlton, a biologist at the Smithsonian Institution in Washington, DC. "So an understanding." Better about what keeps coral healthy is essential ".

In coral reefs, corals and sea algae form lawns or bushes that compete for light and space.

When coral reefs decline due to pollution, overfishing, climate change and other injuries, biologists have seen seaweed plots taking over. Lush seaweed invades or repels larval corals.

Goby Gobiodon histrio

In this scenario, miniature corals, fish and other reef creatures find less safe nooks and cracks to live in. Coral reefs then have fewer fish eating algae, which means less protection for corals.'Missing them, you will have algae-filled beaches'.

Or and Dixson locked an A.nasuta individual, which branched 'like a deer horn' he said. With each coral researchers either leave or leave some of the corpses hidden in the rift.

Later, the researchers examined the reactions to green seaweed Chlorodesmis fastigiata, one of the most toxic reef invaders with corals."It's a very beautiful and ferocious plant," Hay said. If left unchecked, the leaves of this algae will start killing coral tissue two days after exposure.

When the researchers fastened the toxic seaweed strands to lure out the corals' resistance, the two types of flying fish did not help and left after 48 hours. However, two colorful colorful gobies that settle in corals 'are like hedge trimmers,' Hay said.

Both Gobiodon histrio and Paragobiodon echinocephalus goby bite the seaweed until it no longer touches their coral house. Activation is a substance produced by the coral itself, the researchers said.

Gobies ignore seaweed-like ribbons that rub their corals, unless the ice has been treated with water collected next to the coral to be attacked.

In general, corals have sheltered goby fish that are only half as damaged by seaweed as corals without gobies.

Biologists know that Gobiodon histrio has a number of toxins that cause goby fish to leave. Instead of biting and not swallowing seaweed like other non-poisonous gobies, it swallowed seaweed. After each helping the coral against seaweed, poison on goby Gobiodon histrio has increased dramatically to stun the lip killer twice as normal.

This partnership was previously overlooked, showing how little biologists know about the complex web of coral reefs, said John Valentine, Dauphin Island Sea Lab ecologist in Alabama. Gobies remind him of small crabs hiding in corals and clamping to the tube legs of thorny starfish, which these starfish can destroy coral reefs.

Although it is unclear how chemicals alert gobies to work, Hay notes that G.histrio goby swallowed seaweed when biting it."Usually we think big fish control algae for the sake of corals," says Princeton University ecologist Douglass McCauley. Gobies are much smaller than the usual coral protection species that coral conservationists have thought.

Or say: 'Coral reefs need a variety of protected species' . ' Large grazing fishes like grouper and sturgeon have different seaweed palates. And a kind of rabbit fish is one of the few species, along with goby fish that will not only ignore the chunks of algae that have chemicals to protect it. ' 'He stopped and shook himself, like he was too happy , ' Hay continued. Then the rabbit fish chewed these seaweed assassins.