博士 / 國立臺灣海洋大學 / 海洋生物研究所 / 97 / The mud-shrimp, Austinogebia edulis (Ngoc-Ho & Chan, 1992), is sedentary with a deep burrow in mudflat and mainly found on the coast of western Taiwan. Its taxonomy was unclear until that it was revised as one new species in 1992, and then removed to new genus Austinogebia in 2001. Since this species is a locally traditional sea food in Changhua, there was poor understanding in their distribution pattern, population structure, reproductive behavior and the nest structure. In addition, the area A. edulis inhabiting is near Changbin industrial park with high pollution estuaries. A. edulis, as a food, the risk should be estimated.
In this study, a main habitat of Austinogebia edulis in Changhua, Taiwan, was studied. The topics included the distribution pattern, population genetic structure, the nest structure associated with sediment grain size, and the heavy metal pollutants in sediment and tissue of A. edulis were examined.
The result of this study shows that the distribution patterns of the mud shrimp were patchy. The distribution of this mud shrimp may be isolated by the different sediment of environment. Some of these subpopulations may persist and some of them may extinct depended on the steadiness habitat. The environmental change often caused some populations became extinct with the rise of some new subpopulations. The genetic structure shows that there were some unique haplotypes in the larger and older population. The genetic divergence index (FST ) <0.05 and the gene flow (Nm) > 1 show that there is no significant genetic divergence, and the gene flow among subpopulations. Sedentary life style have limited the interbreeding of individuals among patches. Among patches, A. edulis can be dispersal only during the short period of planktonic larval stage to facilitate gene flow.
Simple Y shape was the typical burrow of A. edulis. It was similar to the typical nest structure of Upogebiid shrimps. The chamber density increased with smaller the ratio of the burrow’s diameter and body size indicating narrower space for A. edulis. Also there is a difference in the nest of the male and female shrimp. The male shrimp's nest has more branches. On the other hand, the female shrimp will excavate the deeper nest. It was relatively few cases that the pair male and female interconnected with their burrows were noticed. It is unclear whether this interconnection was the main way for mating.
The total concentrations of heavy metals in A. edulis were measured and their concentrations were as Fe > Mn > Cu > Zn > Ni > Pb > Cr > Co > Cd. The metal concentrations were significantly different according to heavy metal species and the tissues of A. edulis. Concentrations of Fe, Mn, and Pb were primarily found in the exoskeleton; Cd were mainly present in the hepatopancreas; Cu were mainly present in the gill and hepatopancreas; Co, Cr, Ni and Zn were evenly distributed in each tissue. In the sediment, with the exception of Cu and Mn, more than 60% of the metals studied were present in the residual fraction. In contrast, Cu and Mn were dominant in the nonresidual fraction. This indicated that the Cu and Mn concentrations in A. edulis were relatively higher than those of the other metals. The metal concentrations in the mud shrimp, A. edulis detected in the present study were all below the food safety level of USFDA, UKFSC and EU.
| Identifer | oai:union.ndltd.org:TW/097NTOU5270011 |
| Date | January 2009 |
| Creators | 彭紹宏 |
| Contributors | Hwang, Jiang-Shiou, Tsai, Min-Li, 黃將修, 蔡明利 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 170 |
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