Fiction or reality? What species are the "strange fish" in "Avatar 2"?

Review expert: Ancient Mingdi Lian (He Lin)

Zhihu famous science blogger on mollusks

"Avatar: The Way of Water" is now in theaters. The film is set in the ocean and tells the story of a water tribe. In the story, we can see all kinds of mysterious marine creatures and a beautiful underwater world. The various seemingly strange creatures in the film can be found in the real world.

Stills from "Avatar 2"｜fandom.com

Colorful coral reefs

In the ocean of the film, the colorful treasure land is very eye-catching, which is a reference to the coral reefs on the earth. Coral reefs are very important ecosystems in the ocean, mainly composed of reefs and the animals and plants living around them. The reefs come from the skeletons of coral polyps, which are mainly composed of calcium carbonate. Rice-sized coral polyps grow one after another, leaving behind their own skeletons, and eventually form breathtaking coral reefs. During this period, it can be said that they have undergone hundreds and thousands of years of changes, which is also the magic of nature.

The source of coral skeleton growth | Sohu

The key to the growth of coral reefs is the algae that live in symbiosis with corals - zooxanthellae . They not only depend on coral polyps - coral polyps provide inorganic salts and carbon dioxide for zooxanthellae, while the latter photosynthesize organic matter and oxygen to give back to coral polyps. Different corals have different colors. The color of coral polyps comes from their red and green fluorescent proteins and pigments, while the colorful coral reefs come from the impurities added when the coral skeleton is formed. For example, the red color is due to the fact that the coral skeleton absorbs more iron.

Source: pexels

Coral reefs are not only a beautiful sight, but also play a huge role in the ecological environment. According to statistics, as a small ecosystem, coral reefs in the world only account for 0.25% of the ocean area, but they support more than 1/4 of the marine life species, which can be said to be an extremely important part of protecting marine biodiversity.

Coral reefs can also slow down the scouring of waves , because the surface of coral reefs is rugged and has many potholes, the waves are subject to greater friction, and the scouring energy is greatly weakened, thereby reducing the height of the waves on the coast. In addition, coral reefs also have the function of filtering seawater , and the coral polyps that make up coral reefs also contain a variety of highly biologically active compounds that can help humans conduct research on biological drugs.

Source: pexels

Ilu, the plesiosaur king of the sea

In the movie, the heroine rides Ilu in the water, and the heroic scenes must have made everyone "stunned". Ilu's handsome long neck, flippers and rudder-shaped tail are very similar to the extinct plesiosaurs on Earth.

The concept map of "Iru" in the film comes from fandom.com

Plesiosaurs are an extinct class of large marine reptiles named for their long, snake-like necks. They appeared in the late Triassic period and became extinct at the end of the Cretaceous period. As shown in the movie, plesiosaurs are common creatures in the ocean and occupy the middle and upper levels of the food chain. Plesiosaurs have huge bodies and seem to be the material of "kings of the sea", but they are small creatures that feed on fish or shellfish. At the same time, the teeth of plesiosaurs are sharp and slender, and the strong fins give them good mobility, both of which greatly increase the dominant position of plesiosaurs in preying on fish.

Plesiosaur source | Wikipedia

The plesiosaur was first discovered in 1821, and its fossils are also the first ancient vertebrate fossils recognized by science. The "Weiyuan Chinese Pliosaur" fossils discovered in China in modern times also belong to the plesiosaur family.

Wave-skimming pterosaurs, the speed of flying fish and the ferocity of gharials

The scene of the wave-skimming pterosaur carrying the male protagonist leaping on the sea is deeply rooted in people's hearts. This creature is easily reminiscent of flying fish in real life, and its fang-filled, wide-open mouth is more like a combination of a gharial and a flying fish.

Waveskipper Source｜fandom.com

But flying fish are not as big as the pterosaurs, and their temperament is not as majestic as that of the pterosaurs. The body length of flying fish is mostly 5 to 20 centimeters, and the largest record is only 45 centimeters. Their light body, small weight, and streamlined body are the hard conditions for them to fly. However, flying fish do not "fly", but strictly speaking "glide". The key to gliding is to rely on the "ejection start" of the tail wing vibrating at high speed at the moment of leaving the water, and to spread the pectoral fins in the air. This action can make the flying fish reach a high speed of 18 meters per second at the moment of leaving the water, and can glide continuously for 200 to 400 meters.

Flying Fish Gliding Source｜Allmystery

The Xingyi flying wing fish fossil unearthed in Guizhou, my country, is 240 million years old and provides paleontological evidence of the earliest vertebrate gliding on water on Earth.

Xingyi flying wing fish fossil, it is not the same group as modern flying fish, it is the product of independent evolution Source | "The oldest flying fish fossil discovered in Guizhou" Xu Guanghui

The big mouth of the wave-rafting pterosaur easily reminds people of one of the overlords of the Ganges and Indus rivers - the Ganges crocodile . The Ganges crocodile is one of the largest and longest crocodiles in the world. The most amazing thing is its long snout, which is slender and covered with more than 100 fangs. The longest length is 6.5 meters. However, there are only about 300 such majestic gharials left in the world today, and it is a critically endangered species recognized by the World Conservation Union.

Gharial Source | Wikipedia

Akula shark, prehistoric giant Dunkleosteus

The Akula shark is very fierce and symbolizes the culture of the Metkajna clan who live in the water. It is worth mentioning that "akula" means shark in Russian. The Akula shark not only refers to sharks, but also has many similarities with another prehistoric top creature - Dunkleosteus.

Akula Shark Source｜fandom.com

Dunkleosteus is a marine creature that lived in the Devonian period. Its huge bite force and voracious appetite put it at the top of the marine food chain. Dunkleosteus is about ten meters long and weighs nearly four tons. What's even more terrifying about this monster is that its bite force of nearly three tons is enough to cut a shark in half in an instant.

Source of the Dunkleosteus skull in the Queensland Museum | Wikipedia

Source of Dunkleosteus｜"The 'fierce' predator rules the ocean with its bite force"

However, Dunkleosteus's "everything-eating" nature also caused it to suffer from indigestion. Scientists have discovered that fossils of Dunkleosteus are often accompanied by half-digested fish. This shows that the food that Dunkleosteus preyed on was not completely digested. The "raw" eating also shows the brutal dominance of Dunkleosteus from another perspective.

The release of "Avatar 2" has immersed many movie fans in the magnificent movie scenes and beautiful natural landscapes. I hope that while you follow the footsteps of the Na'vi people to guard their homeland, you can also pay more attention to the novel creatures in the movie and find their connection with real life.