Parasites!
From large to microscopic Parasites can live just about everywhere. Some live on plants, some in water and others on animals including humans. A parasite is a living organism that lives on or in another living organism. They depend on the other organism, or host organism, for everything it needs to live. In other words without a host a parasite would starve to death. No matter how cringe worthy some of these organisms are, their relationship to the world around us is fascinating. Parasitologists have discovered so many different parasites that they can’t count how many exist.
Some parasites live in plain sight. These organisms live among humans and we and our pets are the hosts. Lice, leeches, ticks and bedbugs are all parasitic organisms. They live outside the host and are called ectoparasites. Parasites that live inside the host are called endoparasites. Ectoparasites depend primarily on the blood of their host to live. Although some are harmless, others can transmit diseases to the host. For example, if a mosquito bites one host and that host has a parasitic virus, the disease can be passed on to the next person or animal. Some of the diseases for humans include malaria, and Lyme Disease and there heartworms in dogs.
One very fascinating parasite lives on fish, primarily sharks. The name of this organism is copepod. The copepod has helped develop a relationship between sharks and a fish called the remora. The copepod attaches to sharks to eat, then the remora attaches to the shark to clean it off. The remora is not a parasite but they do live off of the skin and parasites on the shark. Another deep diving parasite is the sea lice. This type of lice lives on seals, walrus and other oceanic mammals. They have adapted to live on land or in water and will go to the deepest parts of the ocean with their host.
Some parasites are beneficial. Mushrooms and other forms of fungi found in the forests help with decomposition of organic matter. Their job is to keep the forest floor clean.
Some parasites have disgusting ways to attach or can turn their host into living zombie creatures. The sea lamprey has sharp teeth in a mouth it uses like a suction cup. Another terrifying parasite is the Cordyceps fungi. The Cordyceps begin life as microscopic spores. The spores land on ants. As it grows it begins to control the ant’s behavior. The ant will leave its home in the trees to live on the jungle or forest floor. The new habitat is not good for the ant but the fungus loves it. The fungus has attached to the ant's muscles and the ant is now a Zombie. When Cordyceps is ready it makes the ant climb about 10 inches up a plant and bite a leaf. The ant dies there and the fungus grows like an antenna out of the ants head and the cycle begins again as it releases spores into the air.