Preliminary survey on the population density of black pearl oyster (Pinctada margaritifera Linnaeus, 1758) and shell-epibiontic community along the coastline of southern Penghu Island

• Main Authors: Yung-Lin Hsueh, 薛雍霖
• Other Authors: Jin-Ping Ueng
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/84494925114207138553

碩士 === 國立澎湖科技大學 === 水產資源與養殖研究所 === 101 === For a long time, the collection of black pearl oyster (pinctada margaritifera) as a food source in Penghu islands, has led to the depletion of the species. There were insufficient studies on black pearl oyster stock and species conservation in Taiwan. This study aim to assess black pearl oyster stock of 9 survey sites along the coastline of southern Penghu Island. The transect line survey method was conducted to investigate the population density of P. margaritifera, substrate preferences and the composition of epibiotic community on the shells. A total of 70 black pearl oysters were collected from 4860 m2 survey area. The depth of distribution ranged from 3 to 9 m under sea water level. Mean population density was 1.42 ± 0.36 individual•100 m-2. The highest population density was 8.7 ± 0.9 individual•100 m-2 in Shan Shuei 1 survey site, while the lowest population density was 0.19 ± 0.1 individual•100 m-2 in Shan Shuei port survey site. Mean shell height of P. margaritifera among sampling sites ranged from 31 to 132 mm, the overall mean was 81 mm. For substrate preferences, P. margaritifera was more likely to settle on the hard rock substratum (90%) than coral reef (10%). There were 30 taxa of the composition of epibiotic community on the shells, including Chlorophyta, Phodophyta, Cyanobactera, Protozoa, Porifera, Coelenterata, Platyhelminthes, Mollusca, Echiurioidea, Annelida, Arthopoda, Echinodermata and Chrodata. MDS ordination analysis revealed no difference on the composition of epibiotic community among sampling sites. In general, in comparesion with other studies, this survey suggested the population density of P. margaritifera is relative low in Southern Penghu island. There was also no enough evidence demonstrating that the epibiotic community had negative effect on P. margaritifera. Therefore, over fishing activity might be the major reason to interpret low population density of P. margaritifera and Penghu county government need to protect and conserve P. margaritifera resource in the future.