GM_001系列托福综合写作

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综合写作

The vampire squid is a medium-sized ocean cephalopod that has not been extensively studied. For example, it is not clear what this creature eats. Some biologists have proposed a theory that vampire squids feed on so-called “marine snow” – bits of floating organic debris. However, there are several reasons for doubting that the vampire squid primarily feeds on marine snow.

Minimum-oxygen zones

First, the larger particles of organic debris that form marine snow occur at relatively great depths below the ocean surface. At such depths there is very little oxygen. Few animals can breathe adequately in these minimum-oxygen zones for any length of time. Thus, because of the lack of oxygen, vampire squids would probably die if they had to feed primarily in areas where marine snow is available.

Vulnerability to predation

Second, feeding on marine snow would make vampire squids vulnerable to attacks by predators. Feeding on marine snow requires a vampire squid to keep very still as the organic debris slowly collects on its long arm, which the squid then brings to its mouth. If vampire squids had to spend most of their time feeding in this way, they would be too easy for predators to detect and catch. Whales, sea lions, or large predatory fish could dive down and snap up the motionless squids, seriously reducing their numbers.

Behavior of other cephalopods

Third, the vampire squid is ca cephalopod. Cephalopods are a group of animals that includes octopuses, squids, and cuttlefish. Every other known cephalopod is a hunger that actively seeks out or pursues living prey. Feeding on dead organic material such as marine snow would make the vampire squid very different from all its relatives. Such a difference is not easy to explain.

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