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在初二讲到脊椎动物魚纲时,有几个问题是同学们常问到的,根据我们的了解,愿把这几个问题的看法写出来和同志们一起研究:1.怎佯根据魚鳞上的同心环纹的多少来推算魚的年龄?魚在生活过程中,经历着春、夏、秋、冬四个季节,在每个季节里,魚都要长大,在生长时魚的鳞片也长大。(魚鳞是鱼真皮的衍生物,由近似骨物质组成。)但在四季中魚的新陈代謝是不同的,冬季魚的新陈代謝较慢,魚的生长速度也慢,鳞的生长也如此,所以经过冬天后魚鳞长出一圈既薄又窄且透明的一条环带,叫
On the second day when I spoke of the vertebrate fish class, there are several questions that my classmates often ask. According to our understanding, I would like to write down the views on these issues together with my comrades to study: 1. Scales of concentric ring scales to estimate the age of fish? Fish in life, through the spring, summer, autumn and winter four seasons, in each season, the fish have to grow in the growth of fish Scales also grow up. (Fish scales are derivatives of the dermis of the fish, made up of nearly bone matter.) But fish metabolism is different throughout the four seasons, fish metabolism in winter is slower, fish growth is slower, and scale growth is also So, after the winter fish scales grow a thin, narrow and transparent ring, called