Thesis (Ph. D.) - University of North Carolina, 1961. / Bibliography: leaves 41-46.

The genetic structure of oyster drill Thais clavigera along the west coast of Taiwan were assayed by starch gel electrophoresis. Factors of locality¡]i.e. Shainsan, Taisi, Budai, Chiku¡^,maturity¡]i.e. mature, immature¡^ and sampling time¡]i.e.1999.7~2000.3, 2000.11¡^ were analyzed to evaluate their effect on drill¡¥s genetic structure . Four of the eleven investigated enzyme loci were polymorphic , i.e. Ark, Lap-1, Lap-2, and Pgm-1. Among the four populations , the mean heterozygosity¡]H¡^and genetic distances¡]D¡^ ranged from 0.100 to 0.129 and from 0.0005 to 0.0029, respectively. Therefore, T. clavigera along the west coast of Taiwan belongs to the same population. However, differentiation among populations still existed which was contributed by Ark locus. According to the degree of differentiation, the four populations were ranked as Shainsan¡BBudai¡BTaisi and Chiku . A similar trend was also observed in the four populations, as the drill size increased, the mean heterozygosity and the heterozygosity of Ark locus increased. Sampling time had no significant effect on genetic structure of populations. It is suggested that environmental factors¡]e.g. environmental quality and topography¡^and drill¡¦s reproductive ecology may be important in determining the genetic structure of populations.

Abstract ¡@¡@The present study was undertaken to understand the accumulation of PCBs in the marine environment of Taiwan. Samples including oyster drills, oysters, sediments and seawater were collected from the West coast of Taiwan and analyzed by GC/ECD and GC/MS. ¡@¡@The concentration of PCBs in sediments was 31.05¡ã406.38 pg/g dry wt with the highest one at Tong-Kung. The PCBs in cultural oysters from Tong-Kung was 3.80 pg/g wet wt. Concentrations of PCBs in wild oysters from Tai-Si, Chi-Ku, and Pu-Dai were 123.57 pg/g wet wt, 2.93 pg/g wet wt, and 2.08 pg/g wet wt, respectively. The concentrations of PCBs in snails were in the range of 78.24 to 796.96 pg/g wet wt with the highest one from Tong-Kung. A positive correlations between the concentrations of PCBs in seawater and sediment (r=0.78; p<0.01) and in oysters and snails were also observed(r=0.79; p<0.01). The bioaccumulation of PCBs from seawater to oysters was about 72 times, and the biomagnification of PCBs from oysters to snails was 10 times.

The primary purpose of this study was to evaluate the feasibility of controlling oyster drills in Tomales Bay, particularly Urosalpinx cinerea and Ocenebra Japonica (astropods, Muricidae), with chemicals which have been succesfully tested on a number of oyster pests, Including urosalpinx, in Long Island Sound (Loosanoff , 1956- 1961). The problem was polo to provide information. en the present status of drills alle is the bay, a basic preliminary in evaluating others of pest control.

Thesis (M.S.)--Western Washington University, 2010. / Includes bibliographical references (leaves 104-115). Also issued online.