Did you know?

Did you know? Symbiosis Apr 29 2008

Symbiosis can easily be understood and explained as two organisms living together. There are various sub-divisions of symbiosis, though, and that is where it gets a bit tricky. As a student of biology, I always felt it was easier to understand these complicated scientific relationships when I put them into practical situations.

Symbiosis is very similar to two human beings living or working together, and as most people know, this is not always a mutually beneficial arrangement. 

The first type of symbiosis is known as parasitism – when one component benefits more from the relationship than the other. Here is an easy way to understand it. We have all had “that” housemate! The one who never buys food but eats everything in the fridge, who never washes the dishes but creates the majority of them and who is consistently late with rent, but always has spare cash to go out partying. These individuals rely on others to maintain the balance of their lives, but do not feel the need to reciprocate, and this is a perfect example of a parasitic symbiotic relationship.

In nature, an example of parasitic symbiosis would be a fly laying its eggs in the open wound of an animal. You can see this in the Earth-Touch clip, Flies and maggots consume tsessebe carcass.

The second common differentiation is known as commensalism. This is when one component benefits from the symbiotic relationship, and the other really isn’t bothered either way. A perfect example of this in nature is the hermit crab. (See the Earth-Touch clip, Hermit crabs scuttle in rock pool.) The hermit crab will crawl into shells found on the beach and use these shells as armour to protect its body throughout its life, finding new shells to fit into as it grows.

The last common sub-section of symbiosis is known as mutualism. As the name suggests, this is when both components benefit from their relationship. Clownfish and sea anemones are an excellent example of this mutually beneficial arrangement. (See Anemones and clownfish work together.) The sea anemone has neurotoxins that paralyse the prey that comes into contact with its tentacles. The clownfish, however, is immune to the sting of this anemone and is protected from its predators by it. In exchange for this force field of protection, the clownfish acts as a territorial guard for the anemone, protecting it from anemone-eating fish.

Symbiosis shows how delicately the entire animal kingdom is tied together through a complicated network of relationships. And that includes us. So next time you interact with any other species, try to figure out what type of relationship the two of you have. It will make you feel like you are part of something much bigger than yourself!

– by Leah Buckwalter, Earth-Touch

Image of shrimp cleaning moray © Earth-Touch 2008