Wiki World: predators

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Alien predators are the main danger to the survival of Australia's native wildlife. Foxes and cats are clearing many areas of native animals. Indeed, Australian fauna has been the hardest hit in the world. Bettongs (rat-kangaroo) and wombats for example are oblivious to the danger when a cat or fox is present.

Australian prey have developed camouflage to defend themselves from native predators, but alien predators can see through this.

Thousands of years of isolation have made native fauna vulnerable. Other continents have long had the cat, goat, grey squirrel, mouse, pig, rabbit, red deer, red fox and ship rat, so their native animals have learned to survive and avoid extinction. Responsibility lies clearly with early European immigrants. The damage was done a few hundred years ago.

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Conservation

Global Warming Changes Fish Behavior

Animals will not only die if they remain in regions affected by global warning, they will not know what they are doing. Research shows that rising carbon dioxide changes the behavior of fish.

Carbon dioxide makes the acidity of ocean water rise. Like humans, fish rely on nerve cells to "perceive" the environment they live in, like detecting hot and cost, pain or painless. They also have to rely on environmental cues to behave in a particular way. Fish smell predators so they normally move away from them, but high acidity in the water makes the smell attractive. Small fish move too close to predators, so they are easily caught and eaten.

Fish behave this way due to their nerve cells trying to maintain a balance with the environment. With a rise in carbon dioxide and acidity, bicarbonate and chloride levels rise inside nerve cells, so a feeling of security is not turned off by the smell of predators. A switching chemical, GABA, becomes irregular opening nerves which suddenly release all of the bicarbonate and chloride. This causes dramatic changes in fish behavior.

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Biology

Ancient Large Predator With Strange Eyes Found

Weird eyes of an ancient ocean predator have been found in Australia. It was believed that all types of eyes were known. The creature with the unusual eyes has been identified. It was an anomalocaris, a very large shellfish.

They didn't see the world like whales or even fish. Each eye had 16,000 lenses and was three centimeters in diameter. This is more than the 3,000 lense housefly eye, but not as numerous as the dragonfly eye with its 30,000 lenses. Make no mistake though - eye development was like an arms race, the animals with superior eyes reproducing and surviving. The anomalocaris was a good hunter, moving quickly on their prey in clear waters.

This ancient hunter had an odd shape. It had spined claws on each side of the body and two giant claws on its head. Its eyes were on stalks. The mouth was circular with serrations around the edge pointing inward.

The site where it was found, on Kangaroo Island, holds more strange animals to be investigated. These were the earliest of species, too old to be satisfactorily classified into known animal groups.

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Marine