碩士 / 國立澎湖科技大學 / 海洋創意產業研究所 / 97 / The organs of most marine fish larvae had not formed after hatch, and the living function also had not completed. These conditions made them failure to feeding and escape from predators. Larvae needed nutrition increasingly, and the ability of feeding and swimming was stronger as growing. If larvae could not obtain sufficient feed and avoid the predators, the larvae would die massively. Therefore, to fully understand the development of initial life stage and live function and apply the theory to practical seed propagation is an important technique to reduce the mortality of the critical period. In this study, Lutjanus erythropterus was chosen as the target. Samples were collected continuously. Initial nutrition exchange, feeding ecology, and morphological development of larvae were under observation. The living function and living strategy for each phase was discussed in this study. In order to improve the high mortality caused by starvation, we examined the effects of delay feeding and continuous illumination on feeding and survival rate. This study aimed to understand the needs of larvae toward feed at the early stage and find out the solution.
According to the result of the exam, the yolk sacs and oil globule of Lutjanus erythropterus left not much after 8 HAH, and the PNR point was 92 HAH. It indicated that larvae had to ingest adequate feed for living within short time. The development could be analyzed into four phases, and the living strategies of each were: (1) The stage of undeveloped pelagic (0-4 days after hatching): both of feeding and swimming ability of larvae were undeveloped. Appropriate feeding timing, increasing feeding frequency, and continuous illumination could increase the feeding opportunity. (2)The early stage of organogenesis (4-13 days after hatching): air bladder and ingesting characters appeared, and amount of feeding increased. The nutrition obtained from feed not only supplied the basic need for living but also transferred to organogenesis and development of function. At this stage, to intensify the condition of rearing tank and to provide enough feed would helpful for growth. (3)The intensive stage of organogenesis (13-30 days after hatching): This was the most intensive period of organogenesis. Most of the energy obtained from feeding was transferred to the development of organs and characters. At this stage, larvae needed mouth-fit and nutritional feed. (4) The stage of seeds functional completion (after 30 days after hatching): The feeding and swimming related characters appeared and reached a certain number or differentiation completed. The growth speeded up and reached a stable period. However, the cannibalism became another problem. Grading and controlling the rearing density could reduce the damage caused by cannibalism and make the procedure of seed propagation more success.
| Identifer | oai:union.ndltd.org:TW/097NPHT8833004 |
| Date | January 2009 |
| Creators | Chen-Chia Huang, 黃振嘉 |
| Contributors | Chien-Chang Tseng, 曾建璋 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 95 |
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