2. 外语
  3. Betta, also known as the Siamese fighting fish, common name of a small freshwater fish native to Southeast Asia. Cultivated bett

Betta, also known as the Siamese fighting fish, common name of a small freshwater fish native to Southeast Asia. Cultivated bett

admin2009-04-23  58
问题      Betta, also known as the Siamese fighting fish, common name of a small freshwater fish native to Southeast Asia. Cultivated bettas may be of any color but most commonly are red, blue, or turquoise. The color in males becomes more vivid when the fish is courting or otherwise aroused. The adult measures 3.8 to 6.4 cm (1.5 to 2.5 in.) in length. Like several related species, including the gourami and climbing perch, the betta does not obtain its entire oxygen supply from water but must periodically rise to the surface for air. A cavity above each gill chamber contains a special organ, the labyrinth, used in breathing air. It enables the fish to inhabit oxygen—deficient water that could not be tolerated otherwise. The male builds a nest for the eggs by blowing sticky bubbles of air that collect as a froth at the water’s surface. The male fertilizes into this froth and also briefly guards the hatched young.
    Male fighting fish are bred in Thailand for the purpose of competitive combat, and people gamble on the outcome of the matches. Male bettas are aggressive and even attack their own reflections in a mirror. Fights between male bettas are begun by placing two evenly matched fish in adjacent glass containers. When the fish make attempts at attacking each other, they are removed from the separate containers and placed in a single larger container. When they have recovered from being transferred, they take up a side-by-side position and begin a long series of swift attacking movements. Because their teeth are small, they nibble rather than bite, concentrating their attacks on the fins. Fights are sometimes interrupted while the fish swim to the surface to replenish their supply of oxygen. Although injuries to fins and scales sustained during battle are usually extensive, fighting fish generally recover completely in a few weeks.
选项
答案In the case of cultivated bettas.
解析
转载请注明原文地址:https://kaotiyun.com/show/BspK777K
0

大学英语六级

相关试题推荐
随机试题
最新回复(0)