A relationship—sometimes defined as intimate—between living creatures that feed, protect or are helped by another species is called a symbiotic relationship. Many cases of this unique pairing exist under the sea, although there are similar animal partners, which we will look at, as well.
A small goby fish and a snapping shrimp are an unusual but special pairing. The shrimp is blind but has capabilities such as digging using its powerful claws. The goby has excellent eyesight but cannot dig for its life. They use teamwork to accomplish one of their major goals, safety. While the shrimp digs, it keeps one antenna on the goby’s tail. In turn, the goby watches out for enemies. If danger is forthcoming, the goby warns the shrimp with a flick of its tail so they both can scurry into the newly dug burrow for safety. This type of symbiosis where one warns of danger and the other provides safety is symbiosis under the umbrella of mutualism.
The clownfish eats small invertebrates, which typically harm the sea anemone, so the clownfish is welcome. As a byproduct, when the clownfish expels fecal matter the sea anemone takes them in as nutrients. One final point in this symbiotic dance is that the clownfish is immune to the sea anemone stings, because it coats is own body with mucus, so the anemone provides protection from the clownfish’s predators.
You Are the Host
The opposite happens when one partner benefits but the other is not affected. This relationship represents one host and a parasite. For instance, if a small animal lives atop another such as African oxpeckers that live on hippos backs, the small animal gains protection and the large partner is referred to as a host. In the Afrikaans vernacular, the oxpecker is called the renostervoël, which translates to “rhino bird."
Before closer observation, onlookers originally thought that the oxpeckers were a helpful, tick-eating symbiotic assistant. Now they are known to be more like vampires—birds that suck blood out of open tick wounds. In all fairness, the tick is eaten and perhaps the extra picking the bird does makes the wound heal faster but the oxpecker is more a parasite than a helpmate. An odd factoid is that oxpeckers issue a hissing scream if they are startled, like a danger alarm—do you think that makes an extra aid for the host?
A group of invertebrates called echinoderms (pronounced eck-KI-no-derms), whose word translates to “spiny skin," perform an undersea piggyback ride. They are in a family comprising starfish, sea urchins, feather stars and sea cucumbers. Feather stars look like tall plants and move by walking on their long arms, all the while trapping tiny plants and animals that float in the water. They are referred to as “filter feeders" and different shrimps and crabs live among their tendrils sucking in the nutrients. Sometimes, the riders have a similar color to blend in with their host.
Another more common example of this host and rider is the tick. While it attaches itself to a dog and feasts on its blood, the dog can become sick and the dog gains no benefit from this attachment. Obviously, it is only good for one partner. A definite parasite with no benefit to the other—no mutualism here.
Do No Harm
Another play on the symbiotic relationship is with what scientists call commensal. For example, the tiny blenny fish moves into the center of a large coral colony, which is a safe hiding place. The coral animals that make up the coral grounds do not benefit from the blenny’s presence, but it doesn’t hurt them any either. A partnership that is only good for one is commensal; but of course, here it does no harm, a good thing.
Beasties Make Us a Community
Just about every animal, including people, hosts intimate companions.
For humans, there are two types: endoparasites and ectoparasites. The first group can live inside us, such as a pathogenic fungus, but most enter the body through a wound or are consumed with bad food. They are generally ugly and bad and can make us sick. Ectoparasites live on us or just visit and while they may be annoying, can be controlled. Since our good grooming mostly cuts down on their reproductive abundance, many we will not even see in our soap-driven lifetime such as, body lice. Thankfully, a substantial number of ectoparasites are too small to see without artificial magnification—although there is an ecological landscape in a pore, on a hair, or waiting to be flushed away with sweat.
What We Provide
The human landscape in skin holds tiny holes with water, it is mostly warm, there are no bad animals on the surface and there are quiet times at least part of the day. To the minuscule, we have hills, valleys and some abundant cover in hair.
There are conditions: when people don’t wear shoes, there is no athlete’s foot because fungus needs moisture and dark. While these creatures are despicable to think about, most of them are just trying to carry on. Ticks, flies and mosquitos we swat away or if attached during a hiking episode, are removed with precision. Chiggers, which are a kind of baby mite, are parasitic and while they are quite annoying because they create a shallow well in our skin, they will probably die from scratching or some medicinal product.
What Does It Mean?
Many things can be symbiotic that take place in the world as we know it. An architect can have a symbiotic relationship by the landscape by building respectfully and giving back to the earth. For example, he builds into the mountain and the house is naturally cooled. In turn, he may create less square-footage, taking up less of a footprint.
Can you think of other ways that symbiosis can be beneficial?