碩士 / 國立東華大學 / 海洋生物多樣性及演化研究所 / 97 / Monthly sampling of Caridina gracilipes was carried out from September 2006 to August 2008 at each of the two study sites: Lung-luan-tan Reservoir (landlocked) and Kangkou River (amphidromous). This study investigated two ecological types of C. gracilipes to understand the reproductive ecology of the shrimps inhabited different habitats. Total length and weight, carapace length, sex ratio, recruitment patterns, population dynamics, egg size and egg number were examined. We also constructed the molecular phylogenetic relationship of the species in Taiwan by using mitochondrial DNA COI gene.
The results showed that the population density of the landlocked freshwater shrimps was larger than the amphidromous one, and so was the size. The sex ratio, male vs. female, was 1：1.1 in landlocked population, and 1：0.6 in amphidromous population, respectively. The reproduction of both populations was affected by water temperature and rainfall. Clutch size was smaller but the average egg size was larger in landlocked population as compared to amphidromous population, however the egg mass per female body weight was similar between the two populations, 15.9％ in landlocked and 16.4％ in amphidromous population, respectively. Females with eggs were found in most of the months, indicating a multiple ovulations. Analysis on length frequency distribution using computer package FiSAT, showed that the growth index of landlocked male was L∞＝4.2 mm, K＝0.98 year-1, φ=1.24, and L∞＝6.11 mm, K＝0.9 year-1, φ=1.53 for landlocked female; while the growth index was L∞＝4.85 mm, K＝0.87 year-1, φ=1.31 for amphidromous male, and L∞＝7.57 mm, K＝0.84 year-1, φ=1.68 for amphidromous female. This indicated that the growth rate of amphidromous was higher than the landlocked, while female growth rate was higher than male.
We analyzed the DNA sequence from 27 specimens of C. gracilipes from different localities in Taiwan and concluded that the species can be divided into different groups. According to the high haplotype diversity and high nucleotide diversity and the results of Tajima’s D and Fu and Li’s D test, we suspected that the populations of C. gracilipes experienced bottleneck effect followed by population expansion event. NJ tree shows that the C. gracilipes populations in Taiwan can be divided into two groups, landlocked and amphidromous, with high support of bootstrap value, 100. All of the samples from different reservoirs are of the same type, however, the samples from rivers consist of both types. Based on the biological and molecular differences, we concluded that C. gracilipes in Taiwan might be in the process of population differentiation.
| Identifer | oai:union.ndltd.org:TW/097NDHU5270001 |
| Date | January 2009 |
| Creators | Cheng-Sheng Chang, 張正昇 |
| Contributors | Tew-K. S., 張桂祥 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 77 |
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