Abstract This paper investigated the size of carcass preferred by burying beetles Nicrophorus nepalensis Hope for reproduction. The first experiment was carried out using pairs of sexually mature beetles, which were given four carcasses of mice (ICR strain) of different size and age: 3.18 ± 0.26 g (5 days), 7.23 ± 0.81 g (14 days), 11.39 ± 1.46 g (21 days) and 21.03 ± 1.05 g (28-35 days old). The smaller carcasses tended to be preferred as a source of food and the larger ones for reproduction. In a second experiment, sexually immature individuals, (one male, one female or a pair), were noted to bury a mouse carcass even though it was not being used for reproduction. In the case of sexually mature beetles, the female and pairs would process and bury the carcass as soon as finding it, while most of the sexually mature males did not bury the carcass. Since N. nepalensis are also capable of burying larger rat carcasses, in a third experiment, one male and three females were provided with either a rat carcass (Wistar strain, about 130 g) or a mouse carcass (ICR strain, about 20 g). The size of the brood reared by N. nepalensis on either the rat or the mouse carcasses did not differ significantly. Therefore, the rat carcass was utilized in a considerably less efficient manner than the mouse carcass. However, the offspring raised on the rat carcass were significantly larger than those raised on the mouse carcass.
摘要 本論文研究尼泊爾埋葬蟲 (Nicrophorus nepalensis) 在繁殖時對屍體大小的偏好。第一個試驗以四組不同大小的ICR品系小鼠屍體供成對性熟之埋葬蟲成蟲選擇，分別是3.18 ± 0.26 g (5日齡)、7.23 ± 0.81 g (14日齡)、11.39 ± 1.46 g (21日齡) 與21.03 ± 1.05 g (28~35日齡)，埋葬蟲傾向將較小的屍體作為食用，將較大的小鼠屍體做繁殖之用。於第二個實驗中，未性熟的埋葬蟲個體，不論雌雄或是成對在無法進行繁殖的情況下，皆有埋葬屍體的行為。性熟之埋葬蟲個體，單一雌性與成對成蟲發現屍體便立即進行加工與掩埋，而大部分單一雄性則不立即掩埋屍體。由於尼泊爾埋葬蟲具備埋葬大鼠屍體的能力，在第三個試驗裡提供一雄三雌埋葬蟲以試驗用Wistar品系大鼠屍體 (約130 g) 與ICR品系小鼠屍體 (約20 g)，埋葬蟲於大鼠屍體上所養育的子代數目與在小鼠屍體上者無顯著差異，因此對大鼠屍體的利用率顯著低於小鼠屍體，但於大鼠屍體上所養育出來的子代個體大小，卻顯著大於在小鼠上所養育出來的子代。
| Key words: burying beetles, Nicrophorus, reproduction, brood size, carcass | | 關鍵詞: 埋葬蟲、Nicrophorus、繁殖、子代數、屍體。 |
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