The hammerhead shark is an underwater mystery. Why is its head shaped like a hammer? Nobody is sure. For years, people thought the shark's shape helped it to smell food, or swim faster. But now there is a new idea about this strange animal. It seems that the hammerhead can see better than other sharks. Although its eyes are far apart, it can look up, down, left, and right. It can also see straight ahead. It can easily guess the distance between itself and other fish. This means that the hammerhead shark can hunt very well. This shark changed the shape of its face over thousands of years. As its face got bigger, it saw more and more of the sea around it. It could catch more fish to eat. The hammerhead changed because it needed to survive. 雙髻鯊猶如一海底謎團。牠的頭型為什麼會像一隻槌子? 答案尚無人知曉。多年來,大家都以為雙髻鯊的頭型有助於嗅聞食物,或加快游速。但如今,我們對此奇特動物有了新的見解。 雙髻鯊的視力似乎因為這樣的頭型而優於其他鯊魚。雖然眼距極寬,卻能上下左右觀望,還能直視前方。因此可輕易推測自己和其他魚類之間的距離,這代表著雙髻鯊可輕易地獵捕食物。 雙髻鯊的臉型經歷過數千年的演變。隨著臉部面積增大,更能清楚看見周遭海域的情況,捕獲更多的魚類進食,也因此雙髻鯊的演變原因其實是來自於生存本能。 |