| Summary: | 碩士 === 國立臺灣大學 === 海洋研究所 === 104 === Pelagic larval duration (PLD) of demersal fishes may play an important role to shape adult distribution patterns and population genetic structures. However, the relationship between PLD and population genetic structure remains unclear for Uropterygius micropterus, which has wide distribution, local spawning, poor adult migration ability and narrow niche breadth. Population genetic structure of U. micropterus collected from 8 locations, 3 countries (Japan, Taiwan and Philippines) were analyzed using cyt b and COI genes of mtDNA. Microstructure of otoliths were examined to estimate the PLD and otolith growth rate to investigate the mechanism of larval dispersion. The results showed high haplotype diversity (h) and low nucleotide diversity (π). No population can be distinguished by maximum likelihood phylogenetic tree and minimum spanning network. The AMOVA results demonstrated that > 99 % of genetic variations occur within populations and values of pairwise ΦST ranged from -0.02476 to 0.12067, indicating little to no geographic population genetic structure. The daily increments for all samples ranged from 33 to 98 days. PLDs was shorter and otolith growth rate was higher for the eels collected in Philippines. Higher water temperature might explain the shorter PLD and faster growth rate. PLDs of two populations from eastern Taiwan (51.8 ± 7.2 and 51.7 ± 7.9 days) were significant shorter than the population from southwestern Taiwan (57.6 ± 9.7 days). This result was most likely caused by different ocean current systems between eastern and southwestern Taiwan.
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