關渡濕地位於臺灣北部海岸，地形多樣性包括紅樹林、沼澤以及農墾地。為了闡明生物及非生物因子的關係，我們分析瘤蜷在此濕地分布與環境底質的相關性。採集樣本時間自1998年7月份至12月份，每月採集一次，共以17個地點做為測站。
此次結果顯示，濕地內底質多為粉質壤土，Ph值在7.04～9.00之間。氧化還原電位屬還原態，鹽度則在1～14?之間，而底棲動物在堤坊內以軟體動物12種為居多，堤外則以多毛類2種及甲殼類7種為主。而該區的優勢種瘤蜷，在經解剖檢測其幼貝，其幼貝數與底泥葉綠素a的濃度相關，顯示該生物之生殖策略因環境而改變，種內競爭扮演很重要的角色。
The diverse terrain of the Kuan-Tu wetland in coastal northern Taiwan includes mangrove swamp and farmland. In order to elucidate the relationships among biotic and abiotic factors, we analyzed the distribution of the snail Thiara granifera in the wetland by sampling the species and associated environmental variables monthly from July through December 1998 at 17 stations.
The wetland sediment contained a high silt component, and it exhibited a pH of 7.04~12.0, salinity from 1~14?, and a redox potential (Eh) in reduction state. Twelve species of mollusks were found inside the wetland’s embankment and two species of polychaetes and seven species of arthropods were found outside the embankment. The dominant species was the snai1 Thiara granifera. After dissecting specimens of T. granifera and counting their larvae, we found no significant difference between the mean abundance of broods outside and inside the embankment. We found that the number of larvae was correlated with chlorophyll concentrations in the sediment, suggesting that the former may depend on local environment, with intraspecific competition possibly playing an important role.
