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The Study of Population Biology of Thais spp.Liu, Yu-Chih 06 September 2002 (has links)
Oyster drills are common on rocky shores and oyster (Crassostrea gigas) farming areas in Taiwan. Most studies on the oyster drill (Thais clavigera) were on its impact on the oyster industry. However, there are at least three Thais species in the west coast of Taiwan. And the basic biology of T. rufotincta and T. keluo was insufficient. Thus, the present study was undertaken to investigate population biology of the three congeneric drills(Thais spp.), including feeding rate, reproductive characters and population dynamics.
T. clavigera was distributed from Tamsui to Tongkong along the west coast of Taiwan. But, it was rare at Tongkong. T. keluo was primarily found at Tamsui and Tongkong. The distribution of T. rufotincta was from Tongkong to Tamsui and mostly occurred between Tongkong and Taishi.
Mean feeding rates (¡ÓSE) of T. clavigera, T. keluo and T. rufotincta were 0.054(¡Ó0.010), 0.038(¡Ó0.004) and 0.010(¡Ó0.003) oysters/snail¡Eday, respectively. The feeding rate of T. rufotincta was significantly lower than other species (P<0.05). It is suggested that the major damage on oyster culture is caused by T. clavigera and T. keluo.
The spawning seasons of T. clavigera, T. keluo and T. rufotincta were from November to May, from February to September, and from April to October, respectively. The number of eggs per capsule was correlated with the length of the capsule (P<0.001) in T. clavigera, T. keluo and T. rufotincta and the number of eggs (¡Ó 95% C.I.) among them was 203(¡Ó14), 168(¡Ó15) and 43(¡Ó3) per capsule, respectively. The mean egg diameter (¡Ó 95% C.I.) of the three drills was 185(¡Ó3), 175(¡Ó4) and 240(¡Ó6) £gm, respectively.
Positive curve relationships between size and weight were found among Thais spp. (P<0.001). Using the length-frequency data, analyzed by the ELEFAN (Electronic Length Frequency Analysis) program, the seasonalized von Bertalanffy growth parameters for Thais spp. were estimated. The growth performance index (ø') and growth parameter (K) showed a similar trend, i.e. Chiku>Tamsui>Shiangsan for T. clavigera, Tamsui > Tongkong for T. keluo, and Chiku > Tongkong for T. rufotincta. It is suggested that water temperature and food abundance are important factors affecting drills¡¦ growth in the west coast of Taiwan.
The recruitment of T. rufotincta at Chiku and Tongkong had two peaks. It was different from T. clavigera and T. keluo with only one peak. Futher studies are necessary to elucidate the relationship between recruitment with different peak periods among sites and environment variables such as primary production, salinity, current and so on.
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Les paysans de Morette : un siècle de vie rurale dans une commune du Dauphiné /Garavel, Joseph, January 1900 (has links)
Texte remanié de: Thèse de doctorat--Droit--Grenoble, 1946. / En appendice, choix de documents.
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Die Alterung der Gesellschaft : Ursachen und Folgen des demographischen Umbruchs /Schimany, Peter. January 1900 (has links)
Texte remanié de: Habilitationsschrift--Philosophischen Fakultät--Universität Passau, 2000. / Bibliogr. p. 483-513.
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Bevölkerung und Umweltökonomie : zeitliche und räumliche Perspektiven /Quaas, Martin Friedrich. January 2004 (has links)
Diss.--Wirtschafts- und Sozialwissenschaftlichen Fakultät--Universität Heidelberg, 2004. / Bibliogr. p. 381-395.
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Population et développement au Burundi /Manirakiza, René. January 1900 (has links)
Texte remanié de: Thèse de doctorat--Géographie--Université de Pau et des Pays de l'Adour. / Bibliogr. p. 339-349. Index.
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Bloom dynamics and population genetics of marine phytoplankton : community, species and population aspects /Härnström, Karolina. January 2009 (has links) (PDF)
Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2009. / Härtill 6 uppsatser.
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Spatial inequality of urban poverty in Hong KongPoon, Fu-kit, Benson. January 2009 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 126-132).
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Statistical analysis for capture-recapture experiments in discrete timeWan, Choi-ying. January 2001 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 66-70).
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Population balance in modern industrial society, with special reference to the structure and functioning of American business institutionsChen, Ren Bing, January 1936 (has links)
Thesis--University of Michigan. / Typewritten. Bibliography: leaves [350]-373.
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Essays on demographic transition and economic growthLiao, Pei-Ju, January 2009 (has links)
Thesis (Ph. D.)--UCLA, 2009. / Vita. Description based on print version record. Includes bibliographical references (leaves 109-112).
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