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  3. Some fish seem to be capable of adapting rapidly to climate change. In fact, they might even thrive in the warmer oceans of the

Some fish seem to be capable of adapting rapidly to climate change. In fact, they might even thrive in the warmer oceans of the

admin2016-10-18  18
问题     Some fish seem to be capable of adapting rapidly to climate change. In fact, they might even thrive in the warmer oceans of the future, growing bigger and healthier than they can at present-day temperatures. Evidence gathered over the past decade has suggested that climate change will force fish to migrate to cooler waters, or else face extinction. Signs of such migration have already even been seen. But recent studies have shown that some fish are able to adapt to warmer waters over a few generations.
    Earlier this month, Philip Munday of James Cook University, and his colleagues showed that one key tropical fish species did this by switching some of its genes on and off. Yet there are questions over the potential cost of such an adaptation. The fish’s ability to swim seems to be unimpaired but, as Munday noted: "Maybe we’ll see trade-offs with growth rates. There are no free lunches in this world. " However, for some fish at least, climate change may well carry the prospect of just such a free lunch.
    Work by Jennifer Donelson from the University of Technology in Sydney, Australia, suggests that when a certain species of reef-dwelling fish adapts to warmer waters, it grows bigger and is in better physical condition.
    In her laboratory, Donelson reared(培养)several groups of maroon clown fish(小丑鱼)or anemone fish, which live in coral reefs throughout the West Pacific. She kept one group at temperatures replicating present-day conditions on the Great Barrier Reef, from where the parents of the fish were collected. In addition, she kept another group at 1. 5 °C warmer and a third group at 3 °C warmer, representing the o-cean temperature rise expected by the end of the century.
    After a year of growing, the fish adapted to the warmer temperatures, upping their aerobic metabo-lism(新陈代谢). And that enhancement seemed to bestow other benefits: those reared at temperatures 3°C warmer grew 8 percent larger and 29 percent heavier than fish reared at lower temperatures.
    Donelson says that it is hard to make predictions about how different species will climate with climate change. "But at least it won’t be all negative news for all species," she says.
    Warmer waters could be a good thing for fish that are able to adapt quickly enough, says Munday. But he notes that there could still be other costs of adaptation that were not revealed by this study. Donelson agrees, saying that she did not test the reproduction rates of the anemone fish, for example. Of course, how they cope will depend on the wider coral reef ecosystem, and there is ongoing debate about its ability to adapt to warmer waters. Other studies have also suggested that a similar species of clown fish gets "tipsy"(微醉的)when water becomes more acidic, leading to them taking more risks.
Jennifer Donelson has found in her study that______.
选项 A、reef-dwelling fish can grow better as soon as they migrate to warmer waters
B、parents of the sample clown fish were gathered from the Great Barrier Reef
C、the ocean temperature will rise to 3℃ at the end of the century
D、the metabolic rate of some fish can be enhanced in warmer temperatures
答案D
解析 事实细节题。第五段第一句指出“生长了一年以后，这些鱼类适应了温暖的温度，提高了有氧代谢”所以D)选项的表述“某些鱼类的代谢速率提高”正确。
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