水下惊奇：鱼类世界的奇妙真相
Fish are water-dwelling animals with backbones, fins and two-chambered hearts. While most of us know that fish breathe through gills, there is much more to discover about them. For example, cleaner fish live on the ocean floor and remove parasites from other fish, while flying fish have fins that look like wings, helping them glide above water. Fish come in all sizes, from tiny creatures to very large ones, and they can sleep with their eyes open.
The most common fish in the world is not one we often see. It is called the bristlemouth, a small fish that lives deep in the ocean. Most bristlemouths grow no longer than three inches. To hide from predators, they have light-producing organs on their underside to avoid casting a shadow.
The largest fish is the whale shark, which can reach over 65 feet in length. Despite its large size and strong appearance, the whale shark is gentle and harmless. It feeds on tiny plankton (浮游生物) and small sea creatures by filtering them from the water. Whale sharks can live up to about 70 years unless harmed by humans.
The title of the smallest fish goes to a type of male anglerfish, measuring only about a quarter of an inch. There is some scientific debate about which fish holds this record, but the male anglerfish is currently considered the smallest. The male attaches to a much larger female for life, relying on her for food and movement.
Fish have excellent senses of smell and taste. Some can smell extremely faint chemicals in water — as low as one part per billion. Many have taste buds not only in their mouths but also on their fins and skin. Catfish, for instance, are covered with taste buds from head to tail, including on their whiskers, allowing them to taste food before it even enters their mouth.
Most fish are built to swim forward by moving their tails and cannot easily swim backward. However, some fish like the triggerfish and electric eel can move in reverse by using their fins in special ways. Their ability to swim backwards helps them navigate their underwater world with greater flexibility.
原创编写 版权所有 侵权必究 每日更新 个性化阅读 英语飙升