碩士 / 國立臺灣海洋大學 / 水產養殖學系 / 93 / Abstract
Taiwan landlocked salmon (Oncorhynchus masou formosanus) is an endangered in the world. Monthly sample of 30 to 100 2001year class tagged fish in hatchery for length and weight data to analyze growth dynamics and preparation of further release purpose. The von Bertalanffy growth parameters of Taiwan landlocked salmon were calculated by Ford-Walford and ELEFAN Ι routine method, with current monthly length-frequency data.
The minimum head-top implanted size is 12 cm. And the minimum postorbital implanted size was 17 cm. The mortality rate were about 2 % with no difference for both position implanted. However the recognition rate was higher by postorbital implantation than the other one. The postorbital fall off rate was about 30%, and most of the tags lost occurred within the first two weeks after implantation. There were two to three modes of the frequency distribution both in length and weight. The total length to body weight relation was : W = 0.0081*TL3.124 for pooled male and female, that for female was : W = 0.0116*TL2.9886 , and male was : W = 0.0057*TL3.237. Total length significantly increased with age from 7 month in age to 31 months old: 6.82 ± 0.25 cm (7 Mon), 13.26 ± 0.36 cm (12 Mon), 21.76 ± 0.56 cm (18 Mon), 23.80 ± 0.59 cm (24 Mon), and 29.40 ± 1.09 cm (31 Mon).
Males exhibited higher SGR values from individually tag traced data both in length and weight than females. Hence it was concluded that the growth rate of Taiwan landlocked salmon was higher in male than that in female.
The length of the biggest fish was 35 cm among the 2001 year class at an age of 29 months old. While the two maximum lengths calculated by the Ford-Walford method and ELEFAN Ι routine was 38.91 and 39.92 cm respectively. With a computerized maximum size at no more than 40 cm from cultured population in comparison to the historical largest record around 40 cm, we concluded that there was no size stunting tendency of this species so far. Further strategy to rescue this species will not just focus on the artificial propagation but the release of the fish to those water areas where they once were flourished.
Key words : Oncorhynchus masou formosanus、landlocked salmon、VIalpha tag、individual tracing、age、growth dynamics.
| Identifer | oai:union.ndltd.org:TW/093NTOU5086060 |
| Date | January 2005 |
| Creators | Chih-Hung Lan, 藍智鴻 |
| Contributors | Yii-Shing Huang, 黃沂訓 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 92 |
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