For many creatures, the ocean is a terrifying place. Several marine animals have declined as a result of overfishing and pollution. But cephalopods(头足动物) — a type of invertebrate(无脊椎动物) that includes octopuses, cuttlefish, and squid, have seen a dramatic increase in their numbers over the past 60 years.
Zoe Doubleday, a scientist at the University of Adelaide, in Australia, conducted a study of cephalopods recently. She points out that their population rise is due to the animals’ unique traits.
The creatures can change their color and body shape. They are fast-growing and live for only one or two years. "This allows them to adapt to changing environmental conditions more quickly than other marine species," Doubleday says.
"Rising sea temperatures may be speeding up the animals’ life cycle. They may be growing faster and producing more young. "
Cephalopods live in all of the world’s oceans. They can be found in waters from the freezing polar regions to the warm tropic regions. Because they adapt so easily to their environment, the animals are called "the weed of the sea" .
Will octopuses, cuttlefish, and squid take over the world one day? Some people may wonder. According to Doubleday, that is unlikely. The rise in cephalopod populations could slow down if the animals run out of prey(被捕食的动物) and start feeding on one another. Overfishing could also have an impact on their numbers.
For now, the cephalopod population boom is good news for them and some other sea creatures. "Increases in cephalopod populations could benefit predators(捕食性动物) such as marine mammals and seabirds, which rely on cephalopods for food," Doubleday says.
【小题1】What has caused the number of some marine animals to reduce?| A．Ship transportation. | B．Global oil production. |
| C．Rising sea temperatures. | D．Overfishing and pollution. |
| A．habits | B．features |
| C．hobbies | D．looks |
| A．adapt to the environment quickly | B．change their shapes with season |
| C．prefer to live in the warm waters | D．have a very long life cycle |
| A．Cephalopods | B．Weed of the Sea |
| C．Who will take over the world? | D．The problems faced by marine animals |
