At just a few inches long and living on an affordable diet of flakes, goldfish are often viewed as the world’s most unnoticeable pet — a kind of gateway animal to prepare new caregivers for cats and dogs to come. But their blank stare and expression cover up a little-known and somewhat horrifying fact: Released into the wild and upping their caloric count goldfish can develop into massive fish, damaging local ecosystems.

According to The New York Times, the Great Lakes are currently suffering from an inflow of goldfish. They eat everything from algae (海藻) to plants to animals without backbones and can reach 16 inches to 19 inches in length, weighing in at 4 pounds. And all that consumption is destructive. The goldfish swallow plants that native fish eat. They also consume algae, which promotes further algae growth. Because they’re resistant to changing water temperatures, they can be lasting trouble. They are also forcing native fish out of their natural habitat.

Researchers have observed a significant increase in the goldfish population over the past few decades, a likely consequence of people releasing pets that then reproduce. It’s possible that tens of millions of goldfish now live in the Great Lakes; similar goldfish problems have also been observed in Australia.

Possible interventions include electrical currents that would kill the fish and netting to capture them and control the population in breeding grounds identified by tracking.

Goldfish grew popular in the U.S. in the late 19th century,when the U.S. Commission on Fisheries gave away thousands of them in Washington D.C They’re fairly crafty fish with the capacity to learn some simple tricks. Advocates say the typical fishbowl is too small for them and recommend a tank of at least 20 gallons per fish so they have room to move.

With the right environment, goldfish can reproduce fast and live for decades. But if you’re not interested in keeping them, experts at the U.S. Fish and Wildlife Service suggest donating them to a school, pet store, or interested party — not a local pond.

Cats are domestic(驯养的)animals. They are not only sociable but also fashionable. Domesticated cats would like to form cat communities based on sharing of love and food. And they bond with each other very quickly, which is quite different from humans.

Cats don’t always cry because of being hungry for food. Because cats are social animals, they cry because they want to have company. Cats may not cry every time but they may chatter or mumble. It’s really scary to hear cats chattering like old women. They should be listened and one must talk back.

Meow does not mean that the cat is crying but it is simply a greeting. A cat’s cry may depend on what it is looking for; it can be championship or other things. Cats may cry because of boredom on rare occasions. Cats also need rest and recreation. Cats get stressed when they are ignored. It can be given a name and called, it can be given a pat on the head, but it should not be kicked when it wraps itself around its master’s leg.

A cat follows its master around because of a connecting feeling. Cats look upon its master as a second mother. Even if a cat is old, they never ignore the feeling of being attended and cared for.

Cats use a variety of sounds like mimicking to communicate with one another. They are very moody and they can’t be made like oneself all the time. They have different body language signs which you can tell by the way their tail, ears, paws and body are positioned.

There are many ways by which a cat can be stopped from crying like setting up playful activities with the cat, not ignoring it, taking it to a walk and feeding it regularly. A cat knows how to take advantage of its master’s feelings because they can read them.

The Chinese brake fern (蜈蚣草) — which is native to Asia, southern Europe, Africa and Australia — has a unique ability: It can take in high quantities of arsenic (砷), a harmful heavy metal, from the soil and store it without dying.

Now, a team of scientists from Purdue University has finally unlocked the secrets of how the plant is able to do this. The findings could have important significance because soil and groundwater polluted with arsenic are a potential risk to hundreds of millions of people around the world.

Currently, cleaning up the toxic (有毒的) metal is a laborious and very expensive process. However, the scientists hope that the Chinese brake fern could hold the key to a more effective solution.

“Other researchers have shown that this fern, when grown on arsenic-polluted soil, can remove almost 50 percent of the arsenic in five years,”said lead researcher Jody Banks in a statement.“It takes time, but it's cheap.”

Furthermore, the team said that the new findings could one day be used to genetically (从基因方面) engineer other plants to suck up the toxic metal from the soil, and they should work more quickly and effectively than the Chinese brake fern, thus providing a solution that could potentially reduce the cost and time of arsenic cleanup.

In general, arsenic is toxic to plants and animals due to the fact that it can cause cell death by disturbing a cell's ability to produce ATP, which acts as an energy source. The Chinese brake fern, however, is quite able to prevent the process from occurring, researchers said.

The team identified three genes that exhibit significant activity when the plant comes into contact (接触) with arsenic. When the scientists “turned off”these genes in experiments, they found that the plant died, stressing their importance in protecting against arsenic's toxic effects.