On the Origin of Species: Corsola
The difference between plant an animal can be a subtle one. Over the course of these columns we’ve met plants that behave like animals and animals that behave like plants. Today’s creature takes the confusion further. Coral: is it animal, vegetable or mineral?
It certainly has characteristics of all three. We do tend to think of coral as a solid, rock-like mass. There are whole islands made out of the stuff. Then again, it also seems to be alive, and a living, immobile mass immediately seems like it should some sort of plant. It’s only upon closer observation that it defies all of these expectations and turns out to be an animal. Or, more accurately, millions of tiny, identical animals living together in colonies they’ve constructed. The tough substance we associate with coral is the calcium carbonate exoskeleton formed by these creatures; the creatures themselves have soft bodies.
The first person to argue that coral should be regarded as an animal was the 11th century Persian polymath Al-Biruni. As one of the most important scholars of the medieval Islamic era, biology was a mere sideline for Al-Biruni, but he nonetheless argued that both coral and sponges should be considered animals because of the way they reacted when touched. The idea didn’t catch on, and it wasn’t until 800 years later that another great polymath, William Herschel, made the same claim. Like Al-Biruni, Herschel is more famous for other things – he wrote over twenty symphonies and discovered the planet Uranus, to name a few examples – but it was he who looked at coral under a microscope, and realized that coral cells lacked cell walls, a characteristic component of plants. Coral therefore couldn’t be a plant, and had to be some kind of animal.
Coral belongs to the phylum called Cnidaria. The group includes other simple animals such as sea anemones, hydras and jellyfish. The cnidarians all have specialized cells called cnidocysts, which act like tiny harpoons: when triggered, they fire off a long, needle-like extension that’s anchored to the cell. These are generally used to attack prey and inject poison, while often anchoring said prey to the cnidarian so that it can’t escape. Cnidarians have no brains as such but do have simple nervous systems known as nerve nets, which consist of interconnected neurons spread out across the body.
The Pokémon series has certainly had its share of creatures based on inanimate things: we’ve had plenty of plants, not to mention intelligent rocks, magnets and piles of goo. But Corsola still seems like an odd choice for a Pokémon: out of all animals, coral is surely amongst the least likely to be anthropomorphized. So how good a job does Corsola do of emulating its real life counterpart?
Well, aside from the obvious cases of artistic license – such as Corsola having a face, and being one creature instead of a colony made up of many – there are some similarities that quickly become apparent. It bears a close resemblance to members of the Corallium genus, more commonly known as precious coral or red coral, having the distinctive pinkish hue and branching structure of those species. But it’s when we look at Corsola’s Pokédex entries that the similarities really start to stack up.
For instance, one entry talks about people living in communities built on groups of Corsola. In reality, some very large coral reefs form ring-like structures called atolls, attached to the sea floor at their base, but large enough that the upper part sticks out of the ocean: this exposed part of the coral isn't living, but is composed of the same materials as the reef's exoskeleton, while the living parts begin a short distance below, safely submerged in the water. The parts that are above sea level are called coral islands, and they can indeed be colonized by people. In fact, the capital of the Pacific nation of Tuvalu, Funafuti, is built on one such island.
The Pokédex also tells us that Corsola's branches are considered valuable due to their beauty. This is also true of coral, particularly the kind of coral that Corsola seems to be based on: it's called precious coral for a reason. Another entry discusses Corsola's role as a habitat for smaller creatures, and this is a very important similarity. Coral, with its many branches and deep crevices, makes an excellent hiding place for marine creatures, and there are many species around the world that have made corals reefs their homes. On a microscopic level, corals also host tiny single-celled algae inside their bodies. They have a symbiotic relationship, with the algae providing the coral with some of the sugars, amino acids and oxygen it makes via photosynthesis, while the coral gives the algae protection, as well as some of the ingredients for photosynthesis. The kind of tropical waters in which coral are commonly found tend to be relatively poor in nutrients, so this mutually beneficial relationship serves both species well. These algae are also responsible for the many bright and impressive colors seen in coral.
And this brings us to one other similarity between Corsola and real coral: their need for unpolluted water and their reaction to poor conditions. The relationship between coral and their algae is a delicate one, and it can easily be affected by outside conditions. Rising ocean temperatures (a product of climate change) and acidity (the result of more carbon dioxide in the atmosphere being absorbed by the ocean) put coral under stress. If this is severe enough, the coral will be unable to maintain its relationship with the algae, and will be forced to eject them. This ultimately makes matters worse as the coral will no longer receive the benefits of these algae, and it also results in a very visible sign of coral decay. With the loss of the pigmented algae, the coral appears white and skeletal, and this effect is known as coral bleaching.
Coral dying off has more severe consequences than you might think. The thriving habitats full of fish using coral for protection and camouflage will break down, ultimately affecting the humans who need those fish for food. Coral is a kind of barometer for the health of the oceans, and it's undoubtedly in humanity's best interests to see that it remains in good shape. It's remarkable enough that coral supports the very ground some people walk on, but in truth, coral supports us even more than that.