Category Archives: Speciation

The Mystery of Loberg Lake

Hi! This week with Gamed Academy I learned about Loberg Lake, which is a lake in Alaska. This lake had two types of 3 Spined Stickleback fish. The fully armored ┬áhas multiple large spines (even though it is technically a THREE Spined Stickleback…) on its back and stomach as well as “armor” on its sides. The low armored variety has only three smaller spines on its back, and no armor on its side. Which fish would you rather be? I’ll bet you would rather be the fully armored one. We’ll see later if you’re correct!

Let’s get a few more facts before I begin with the story.

  • Fully Armored Stickleback like saltwater better, so they live in the sea and come back to the lake to breed. They get there through rivers and streams coming from the ocean. Only some stay behind in the lake, though, so there are far fewer of these than the Low Armored at Loberg.
  • Low Armored Stickleback like freshwater and can’t live in the ocean (as far as I know), so they stay in Loberg Lake and don’t leave like the Fully Armored fish do.

Now, let’s get on with the story,

It’s 1984 and the population of Loberg Lake is large. There are lots of Low Armored Sticklebacks and quite a few Fully Armored Sticklebacks. Then, some people decide to poison the lake to start over. They want to put Salmon and Tuna in the river and want nothing to do with the Sticklebacks.

Over the years, the Stickleback start to reappear. The Fully Armored Stickleback came from the ocean every year, and the Low Armored Sticklebacks came from somewhere (I’m not sure where they came from… I just know they came back). Now, there are more Fully Armored Sticklebacks than the Low Armored Sticklebacks.

Over some more years, the population starts to shift. There are now more Low Armored Sticklebacks than Fully Armored Sticklebacks! What happened?! Don’t worry, it’ll all make perfect sense in a moment.

Have you ever seen a baby dragon fly hunt? It doesn’t sound that terrifying, I know, but trust me. It is. Google it if you don’t believe me.

The issue with being a fully armored Stickleback is that they grow slower, meaning that the dragonflies have more time to hunt them. The low armored Sticklebacks, on the other hand grow relatively quickly, meaning that they are less likely to be hunted by the babies.

And that’s why it’s better to be a Low Armored Stickleback, and not a Fully Armored Stickleback.