Two Komodo dragons have hatched at the Sedgwick County Zoo in Kansas, US, apparently without a father.
The newborn dragons, both males, are believed to be the first in North America to have hatched by parthenogenesis. Parthenogenesis occurs naturally in some species, including invertebrates and lower plants. It happens more rarely in some vertebrates.
Two other known cases in which Komodo dragons hatched by parthenogenesis were at the London and Chester zoos in England in 2006.
PHOTO: AP
The zoo in Wichita is having DNA testing done to document the mother's and the babies' genetic structure. There is still a ghost of a chance that a male's sperm was stored on the female's body.
Komodo dragons are one of the few species capable of storing sperm, said Don Boyer, curator of reptiles and amphibians at the San Diego Zoo.
The Sedgwick County Zoo has had this female and one other since 1993, when they were less than a year old.
"We never had a male dragon at the zoo," said Nate Nelson, the zoo's curator of amphibians, reptiles and fishes.
One of the Kansas zoo's females, Gaia, laid at least 17 eggs on the nights of May 19 and 20, 2007.
Because the English zoos had documented parthenogenesis, the Sedgwick County Zoo checked to see whether the eggs were fertile.
Only two of the 17 eggs were hatched - one on Jan. 31 and the other Feb. 1 - because the zoo does not have room for more dragons, Nelson said.
One is 40.6cm long; the other is 43.2cm. Komodo dragons can live 20 to 40 years. Males can reach 3m long and weigh as much as 90kg; females grow up to 2m and weigh as much as 55kg.
Komodo dragons are endangered, with between 3,000 and 5,000 in the wild.
(AP)
兩隻科莫多巨蜥寶寶最近在美國堪薩斯州威奇塔的塞奇威克縣立動物園中破殼而出；牠們顯然並沒有父親。
這兩隻剛出生的雄性科莫多巨蜥據信是北美洲透過單性生殖孵出的首例。某些生物天生具有單性生殖的能力，包括無脊椎動物和低等植物，但單性生殖在脊椎動物中較為罕見。
另外兩隻經由單性生殖孵出的科莫多巨蜥，去年在英國倫敦動物園和切斯特動物園亮相。
這家位於威奇塔的動物園，正在為這兩隻莫多巨蜥寶寶和牠們母親進行DNA基因比對；雄性精子是有可能存在於雌性動物體內的。
聖地牙哥動物園爬蟲類和兩棲類館的館長表示，科莫多巨蜥是少數能由雌性儲存精子的生物。
塞奇威克縣立動物園自從一九九三年就飼養了這隻雌性科莫多巨蜥和另外一隻，當時牠們都還不到一歲大。
該動物園的兩棲類、爬蟲類和魚類館的館長奈特．尼爾森說：「我們動物園從來沒有養過雄性的蜥蜴。」
這隻名叫嘉雅的雌性科莫多蜥蜴，於去年五月十九和二十日晚上產下了至少十七顆蛋。
由於英國動物園已有單性生殖孵化的紀錄資料，因此塞奇威克縣立動物園檢查了這些蛋是否有授精。
尼爾森說，結果這十七顆蛋中只有兩顆蛋孵化，一個在上個月底，另一個則是在本月月初，因為動物園沒有足夠的空間飼養更多的蜥蜴。
這兩隻蜥蜴寶寶，一隻長四十點六公分，另一隻則是四十三點二公分。科莫多蜥蜴的壽命長達二十年至四十年。雄性蜥蜴可以長到三公尺長並重達九十公斤；雌性蜥蜴則可以長到兩公尺長並重達五十五公斤。
科莫多蜥蜴為瀕臨絕種動物，目前只剩三千到五千隻存活在野生環境中。
（美聯社／翻譯：楊鴻泰）
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