| 洪湖鲫鱼种群的研究及洪湖鱼类资源小型化现象的初步探讨 | |
| 张国华 | |
| Subtype | 硕士 |
| Thesis Advisor | 曹文宣 |
| 1989 | |
| Degree Grantor | 中国科学院水生生物研究所 |
| Place of Conferral | 中国科学院水生生物研究所 |
| Degree Discipline | 水生生物学 |
| Abstract | 本文研究了洪湖鲫鱼的种群，并对洪湖鱼类资源小型化现象产生原因进行了探讨。鲫鱼自然死亡率、捕捞死亡率分别分0.33、0.27。月死亡率变化表明，禁渔期的实行有助于保护鱼类资源。雌雄鱼生长有显著性差异。幼鱼生长缓慢。调查了繁殖特性，性成熟体长降低，低龄组间性比无显著性差异。提出鱼类资源小型化分为种类小型化和结构小型化。环境变迁、捕捞是鱼类资源小型化的主要外在原因，不同种鱼类种群补偿机制差异则是主要内在原因。提出解决鱼类资源小型化的对策。 |
| Other Abstract | Specimens of goldfish (Carassius auratus auratus) were taken at frequent intervals from April, 1988 to March, 1989. The total mortality was 0.60, with the natural mortality of 0.33 and the catching mortality of 0.27. Analyses of monthly mortalities of each age suggested that the closed season had conduced to protecting of fisheries resources. The formula of the fish length corresponding to the scale radius was selected as follows: L = 9.7266 + 23.9808·R Where L = length of fish R = scale radius Selective fishing mortality may be the cause of Rosa Lee's phenomenon. The Von Bertalanffy expression for goldfish was written as: L_t = 159.38 {1-exp[-0.2289 (t + 0.2021)]} Where Lt in mm. Females grew significantly faster than males after one year of age. Majority of goldfish reach maturity at 2-age. The range of sizes at first spawning was 39-60mm. Goldfish had a prostrasted Spawning period from March to July, and an analysis of size frequency distribution of eggs showed that goldfish sheded eggs in batches. The sex ratio of females to males was 2.5:1 in younger age groups with a more dominance of females in older age groups. Relationship between fecundity and length was presented by: F = 10~(-4) * 4.6001 * L~(3.5420) "Diminution phenomenon" refers to a few species of short-life span, slow-growing small fish dominate the fish yield, some of long-life span, fast-growing large fish disappear and abundance of other species decrease drastically. Fish stocks in a "diminution phenomenon" lake become younger and have smaller lengths at each age. Causes leading to the "diminution phenomenon" may be: (1) environmental alterations (obstruction of passages between Honghu Lake and rivers, overblooming of submerged plants, changes of water depth, etc.); (2) overfishing; (3) compensatory mechanisms. |
| Pages | 47 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.ihb.ac.cn/handle/342005/12768 |
| Collection | 学位论文 |
| Recommended Citation GB/T 7714 | 张国华. 洪湖鲫鱼种群的研究及洪湖鱼类资源小型化现象的初步探讨[D]. 中国科学院水生生物研究所. 中国科学院水生生物研究所,1989. |
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