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本文探讨补充量(1龄组鱼)不定的鱼类种群模式。不同年龄组世代的死亡率(模式)列于表1,年龄组成的绝对值变动列于表2。为了根据相对的年龄组成测定死亡率(所有世代的死亡率都一样),必须了解每年1龄组的数量增减率。表3列出模式种群相对年龄组成的变动。表3第二栏为1龄组数量与上一年比较的变化资料,最后一栏为整个种群的数量变化。假如要测定3龄组到4龄组的死亡率,如1955年(见表3),年龄组的比为8.7:9.9。当该年3龄组为1龄组时(1953),年补充量比上一年减少56%。因此,上述年龄组的绝对比为19.75:9.9,世代从3龄到4龄组的死亡率为50%。
This article explores the variable fish population (fish of the first instar) variable fish population pattern. Mortality rates (patterns) for generations of different age groups are shown in Table 1, and the absolute changes in age composition are shown in Table 2. In order to determine mortality based on relative age composition (all generations have the same mortality rate), it is necessary to know the rate of change in the number of groups in the first-year age group. Table 3 shows the relative age composition of the model population changes. The second column of Table 3 shows the changes in the number of 1-age groups compared to the previous year, with the last column showing the change in the population. If you want to determine the mortality rate of 3 to 4 age group, such as 1955 (see Table 3), the age group was 8.7: 9.9. When the third-age group was the first-age group (1953), the annual supplementation decreased by 56% over the previous year. Therefore, the absolute ratio for the above age group was 19.75: 9.9, and the mortality rate for the 3rd to 4th generation generation was 50%.