The world's largest creature has been discovered: 180 kilometers long!

Armillaria ostreatus, once the world's largest organism, has lived in Oregon, USA for 2,400 years. This fungus covers an area of ​​890 hectares and its total weight is comparable to that of three 200-ton blue whales.

Armillaria ostreatus

However, a seaweed has now taken over the crown of Armillaria ostreatus and become the world's largest organism.

Next, let’s find out why this largest creature in the world, which is 180 kilometers long, can grow so big?

Seaweed is not what it seems

Seagrass is one of the most common organisms in the ocean and is currently the only higher angiosperm that can live entirely in it.

Seaweed once went through the process of moving from the sea to the land, and then returning to the ocean after several cycles along with other plants. Its official return to the ocean can be traced back to about 100 million to 70 million years ago.

Like a seaweed swaying in the wind

Because they carry genes from early terrestrial angiosperms, when they reintegrate into the marine ecosystem, they show obvious differences from plant groups such as salt marsh plants and algae.

Most importantly, while other plants and animals were constantly evolving, seagrass was already in a state of decay, with only more than 70 species now.

Largest seagrass bed discovered

The largest seagrass bed discovered by scientists this time is located in Shark Bay in the westernmost part of Australia.

Shark Bay

This World Heritage area is a paradise for a large number of flora and fauna, and the seagrass here is a testimony to the evolution of Shark Bay.

This sea area has the largest number of seaweed species in the world. Since seaweed plays an important role in ecological balance, scientists from the University of Western Australia and Flinders University have been studying these seaweeds.

From 2012 to 2019, scientists collected samples from 10 areas in the Shark Bay seagrass meadow, collecting a total of 144 samples.

seaweed

When scientists extracted DNA from the seagrass, they found that the diversity statistics of samples from nine of the 10 regions were almost identical, with almost identical multi-locus SNP profiles.

The most outrageous thing is that the seagrasses in seven of the areas share a multi-locus gene, which means that they are actually the same seagrass.

Scientists estimated the range of this seaweed and found that its radiation range reaches 180 kilometers and the entire area reaches 200 square kilometers, which is more than 22 times larger than the previous Armillaria ostreatus.

Seagrass beds

Asexual seaweed

The exact age of the seagrass bed is difficult to estimate. Scientists can only conclude that the seagrass bed is about 4,500 years old based on the age of Shark Bay and the growth rate of the seagrass.

So how did it grow so big?

The environment in Shark Bay is not actually very good, but the abundant sunlight and some nutrients here are enough to sustain the survival of this seaweed.

However, it is thanks to its reproduction method that it can grow to such a large size.

Crazy self-replication

There are two ways for seaweed to grow. One is sexual reproduction, which is when male and female plants pollinate in the water, then bloom and bear fruit, relying on the flow of seawater and other aquatic organisms to spread seeds.

The other is asexual reproduction, where a seaweed plant simply replicates its own genes to create new copies, and these offspring will have the same genes.

Scientists discovered that this seaweed species indeed reproduces asexually, because DNA sequencing showed that it has 40 chromosomes, twice as many as other seaweed species.

Seaweed has DNA from both its parents

Scientists call this plant a polyploid, in part because its reproduction is essentially determined by its own state and can therefore reproduce indefinitely unless it is damaged.

But when scientists studied polyploid asexual reproduction, they found that in most cases, their clones would eventually become fragmented over time.

When genetically identical ramets can no longer be physically connected through rhizomes, they gradually become new individuals.

Hybrid seaweed

But this seaweed overcame such difficulties, and scientists had doubts about whether seaweed had such ability.

The resilient seaweed

The scientists' research results, published in the Proceedings of the Royal Society B, show that this seaweed is likely a super organism that is a hybrid of two related species.

Half of it may come from algae, and the other half is an unknown species. Scientists believe that it is the genes of this unknown species that allow it to continue to grow in a gradually warming global environment.

This gene may provide a reference for scientists to study and respond to the climate crisis.

Seagrass is a breeding ground for many marine organisms

The reason for this conclusion is that in recent years, Shark Bay has continued to experience heat waves due to the influence of climate change, which has caused serious damage to the organisms in the area.

However, between 2010 and 2011, scientists discovered that the seagrass in this area seemed to remain unfazed by the heat wave and continued to reproduce in an orderly manner.

Because here, there are more buds and greater density of leaves.

Of course, scientists said that their research on this giant seaweed is not because of how big it is, but because of the great value of the seaweed.

Seagrass bears witness to the evolution of Shark Bay

Giant seagrass beds have great value

The survival and death of seagrass will greatly affect the marine ecosystem.

Especially in Shark Bay, which has the most seagrass, once these seagrasses die due to climate change, they will gradually rot on the seabed and then breed bacteria.

This is a fatal hazard to seawater and marine life, and it should be noted that seagrass beds provide habitats for a large number of marine life.

If these seagrass beds disappear in large areas, it will be like losing their homes for survival for these creatures.

Seaweed: Danger!

In addition, as an angiosperm, seagrass beds naturally have a strong carbon fixation ability.

The ocean is the world's largest carbon reservoir, containing 50 times more carbon dioxide than the atmosphere and 20 times more than terrestrial ecosystems.

Every year, the ocean needs to absorb excess carbon dioxide from the atmosphere into its "belly", and then store the carbon dioxide on the seabed through air currents. It is understood that the ocean absorbs about 2 billion tons of carbon dioxide from the atmosphere every year.

Seagrasses play a huge role in this. Once these seagrasses die, the ocean's ability to fix carbon will be greatly reduced.

The ocean is the largest carbon sink

Therefore, now this largest creature in the world is relying on its own strength to protect the ecological environment of the ocean and even the entire earth.

Scientists are now studying intensively what makes this seaweed special. The results may lead to ways to give seaweed or plants in other areas the same ability, ultimately optimizing the earth's ecological environment.

As an asexual organism

In fact, Armillaria ostreatus is able to grow to such a large area by also using asexual reproduction.

Cui Yan of the Han Dynasty wrote in "Da Zhi": "A tall tree has no shade, and a single tree does not form a forest."

A single tree cannot make a forest

Pando, a lone tree in the forest

However, asexual reproduction now has the potential to create a single-tree forest, with the trembling aspen in Utah, USA being a representative example.

This trembling poplar tree covers an area of ​​0.43 square kilometers, which is about the size of the Vatican. It is affectionately called "Pando" by people.

As early as 1976, scientists discovered that this forest was asexual. After years of reproduction and development, the original trembling poplar forest had cloned into more than 47,000 trees, with a total weight of more than 6,000 tons.

Pando

Scientists estimated its age and found that although most of the tree trunks are only more than 130 years old, the entire Pandolin has existed for thousands of years. Some studies even believe that it is more than 14,000 years old.

One tree not only multiplies into a forest, but also supports an entire rich ecosystem, with at least 68 species of plants living in it, and many animals also living under its protection.

Studies have shown that Pando's life is disappearing due to a variety of reasons, including global climate change and animal gnawing.

Deer eating Pando

Global climate change has caused a gradual decrease in precipitation in this area and an increase in temperature, making it almost impossible for Pando to grow new leaves.

This has caused Pando's coverage to gradually decrease, affecting the entire forest ecosystem.

In order to survive, Pando can only work hard to adapt to this rapid change, and scientists' research on seagrass beds may provide some reference for Pando's survival.

Climate change seriously harms life on Earth

As the driving force behind global climate change, humans also need to take action to protect the earth's creatures.