碩士 / 國立臺灣海洋大學 / 水產養殖學系 / 93 / Abstract
Moray eels are the commercially important fishes in Taiwan. Studies about the fundamental biology of local moray eels are pretty few. There were study two species of Taiwan morays, Echidna polyzona and Gymnothorax chilospilus were selected for the study of their fundamental biology.
The length-weight equation for E. polyzona was W=0.0004 TL3.3916. G. chilospilus was W=0.0011 TL3.0409. The most frequent occurring length of captured E. polyzona were between 40~50 cm. And most frequent occurring length of captured G. chilospilus were between 30~40 cm.
About reproductive results, the average total length, weight and GSI of male E. polyzona was 48.18±9.11 cm, 199.37±111.83 g, and 0.93±0.49 respectively. And the respective data of female E. polyzona was total length: 47.38±8.73 cm, average weight: 209.38±137.62 g, GSI: 3.41±2.94, fecundity: 23783±15298 and egg diameter: 0.92±0.07 mm. The average total length, weight and GSI of male G. chilospilus was 32.51±2.98 cm, 44.09±12.58 g, and 1.98±0.80 respectively. And the respective data of female G. chilospilus was total length: 28.15±2.48 cm, average weight: 24.21±5.68 g, GSI: 4.61±5.59, fecundity: 5032±1052 and egg diameter: 0.96±0.10 mm . For both male and female of the two species, the right gonad was bigger than the left gonad. The reproduction type of these two species was gonochoristic concluded by the monosexual characters of all the gonads examined.
About dentition results, the shape of teeth on the premaxillary plate was the characteristic dentition for sex dimorphism distinguishment in E. polyzona . Male exhibited a series of sharp teeth in the peripheral of the premaxillary plate ,and the median premaxillary teeth disappeared in large male. In female the teeth of the premaxillary plate were conical, which beared conical median premaxillary teeth in the medial part of premaxillary plate. The large the body-length increased, the more the number of the male’s median premaxillary teeth was found to disappear. Increased amount of vomerine teeth and dentary teeth were found with increasing sizes for both male and female. Dentition of G. chilospilus, sex dimorphism is mainly found in the number of teeth. Teeth of females are more numerous than males in each part almost. Males do not have inner maxillary teeth and inner dentary teeth. Following the body-length increase, teeth of outer maxillary teeth and outer dentary teeth will decrease a little in G. chilospilus.
After eight to ten monthes rearing, the growth rate of E. polyzona that with 10~20 cm body-length interval was 13.27 %, the weight gain 0 %. In 20~30 cm body-length interval, the growth rate was 5.80 %, the weight gain 36.73 %, In 30~40 cm body-length interval, the growth rate was -2.06 % the weight gain -23.62 %. After eight monthes rearing, the growth rate of G. chilospilus that with 20~30 cm body-length interval were 14.28±6.55 %, the weight gain 84.87±47.62 %. In 30~40 cm body-length interval, the growth rate was 8.70 %, the weight gain 75.35 %.
| Identifer | oai:union.ndltd.org:TW/093NTOU5086052 |
| Date | January 2005 |
| Creators | Chou-Shen Yang, 楊朝森 |
| Contributors | Hong-Ming Chen, 陳鴻鳴 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 101 |
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