台灣鈍頭蛇之食性研究

Food habits of Taiwan slug snake(Pareas formosensis).

蔡欣吟(Sin-Yin Cai)

指導教授 ： 杜銘章

國立臺灣師範大學/理學院/生命科學研究所/碩士(2007年)

摘要

食性探討能幫助我們勾勒出一個物種在生態系中所扮演的角色，以及和其他物種間的能量傳遞，是生態研究中重要且基礎的一環，然而亞洲鈍頭蛇亞科（Pareatinae）的蛇類，缺乏探討食性的文獻。本研究欲探究分類地位屬於該亞科的台灣鈍頭蛇，我以2005年5月~2006年5月採集自台灣北部之台灣鈍頭蛇，利用實驗室內餵養的方式，在黑暗中測試台灣鈍頭蛇的食物類別、捕食行為以及蛇大小與獵物體型大小之關係。
結果顯示：（1）五種測試食物，只有腹足綱動物才能引起台灣鈍頭蛇的攻擊（p<0.001,N=15）﹔（2）台灣鈍頭蛇對於水棲性的前鰓類及有肺類蝸牛，攻擊率皆低。遭遇陸棲性蝸牛時，蛇對有肺類的攻擊率顯著大於對前鰓類。且蛇攻擊蝸牛腹足後方的捕食成功率大於從蝸牛前方。（3）蝸牛殼口附近若有阻礙物，則會明顯降低台灣鈍頭蛇的捕食成功率（p<0.05,N=16）。（4）台灣鈍頭蛇捕食斯文豪氏大蝸牛之相對重量比的上限範圍為0.16~0.47（N=15），蛇的頭寬與蝸牛殼口寬兩者呈顯著正相關（p<0.0001），另外頭寬和相對重量比的上限（最大蝸牛重/蛇重）亦呈正相關（p<0.01）。相較於雄蛇，雌蛇能捕食較大的獵物，但兩者的相對重量比之上限沒有顯著差異（10.9），其吻端長度（上顎長-下顎長）與被捕食蝸牛的腹足尾部長也無顯著相關（ｐ>0.5）。雄蛇與雌蛇所能處理的相對下限比（最小蝸牛重/蛇重）沒顯著差異（p>0.05），意即雌蛇與雄蛇捕食小蝸牛的能力沒有顯著的不同。

關鍵字

台灣鈍頭蛇 ； 食性 ； 腹足綱 ； 有肺類蝸牛

並列摘要

Animal dieterial information gathering is necessary during the process of getting further understanding of them. And this kind of baseline data is not only useful for researchers to know more aobut animals, but also needed when researchers want to know the roles they play in the ecosystem.
However, the Pareatinae snakes is in lack of related literatures focused to their diet and foraging behavior as well. Taiwan slug snake (Pareas formosensis), the only Pareatinae snake in Taiwan, is in similar situation. This study is conducted between May 2005 and May 2006, all the Taiwan slug snakes for the tests in the study was collected at North Taiwan. In the condition of totally darkness, tested individuals were provided with food of different items and characteristics.
And we found:（1）. Among 5 food items we provided, only gastropoda will initiate snakes’ attacking behavior. （2）Very low attacking rate was found when aquatic pulmonate and prosobranchia snail offered, and higher successful foraging was found when snake attacking from the posterior part of their preys. （3）Obstacle at the snail aperture will hampered snakes’ attcking. （4）When the snail weight is divided by the snake consuming it, mass ratio, upper limit range snakes preyed is 0.16~0.47. And the head width of snakes are significant positive correlation with head width of snails (p<0.0001), and with upper limit of mass ratio of snail to snake (p<0.01). Female snakes could ingest larger snails than male ones can, but the upper limit of mass ratios they can ingest are not significant difference.（5）The lower limit range of the mass ratio of the snails (Nesiohelix swinhoei) to the snakes is 0.013~0.047 (N=11).There is not significant correlation with head width of snake and aperture width of snail (Nesiohelix swinhoei) (p>0.9). The lower limit of mass ratios of ingested snails to snakes are not significant difference between males and females (p>0.05).

並列關鍵字

Pareas formosensis ； food habits ； gastropoda ； pulmonate

參考文獻

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