Paleogenetic evidence for a past invasion of Onondaga Lake, New York, by exotic Daphnia curvirostris using mtDNA from dormant eggs
Paleogenetic evidence for a past invasion of Onondaga Lake, New York, by exotic Daphnia curvirostris using mtDNA from dormant eggs
复制标题
DOI：
10.4319/lo.2000.45.6.1409
复制
发表时间：
2000-09-01
影响因子：
4.5
通讯作者：
Hairston, NG
中科院分区：
文献类型：
--
作者：
Duffy, MA;Perry, LJ;Hairston, NG
枝洋类具有抗滞育的卵和快速的孤雌生殖等特征，使它们成为新栖息地的有效入侵者。几乎所有已知的入侵都是成功的，也许是因为失败的入侵很难被发现。然而，通过研究滞育卵子库，有可能确定过去失败的入侵。在纽约奥农达加湖的沉积物中发现了水蚤，它既不能孵化，也不能用卵壳形态来识别。相反，我们使用从滞育卵中提取的线粒体脱氧核糖核酸（mtDNA）的12S核糖体核糖核酸（rRNA）基因序列来鉴定未知的水蚤。我们将这些DNA序列与在Onondaga湖收集的水蚤物种的形态鉴定序列以及其他北美水蚤物种的已发表序列进行了比较。入侵者被鉴定为弧形水蚤（Daphnia curvirostris），这是一种欧亚物种，以前只报道过一次来自加拿大西北部的北美物种。在奥农达加湖的发现标志着该物种的活动范围扩大了4500多公里。根据沉积物表层资料，曲线藻在1952年前后首次出现，在污染高峰时期（1950 ~ 1980年代）丰度达到最大值，1983年湖泊水质好转后基本消失。与在Onondaga湖发现的另一种外来枝海目D. exilis一样（Hairston et al. 1999a），湖岸的化学工业活动很可能是入侵D. curvirostris的原始来源，污染使该物种得以在湖中定居，污染的减少最终导致其从水柱中消失。
Cladocerans possess traits such as resistant diapausing eggs and rapid parthenogenetic reproduction that make them efficient invaders of new habitats. Nearly all known invasions have been successful, perhaps because failed invasions are difficult to detect. It is possible, however, to identify past failed invasions, by studying the diapausing egg bank. Daphnia ephippia were found in the sediments of Onondaga Lake, New York that could neither be hatched nor identified using egg-case morphology. Instead, we used sequences of the 12S ribosomal ribonucleic acid (rRNA) gene of mitochondrial deoxyribonucleic acid (mtDNA) extracted from diapausing eggs to identify the unknown Daphnia. We compared these DNA sequences with those generated from morphologically identified Daphnia species collected in Onondaga Lake, and with published sequences for other North American Daphnia species. The invader was identified as Daphnia curvirostris, a Eurasian species that has been only reported once before from North America, in extreme northwestern Canada. The discovery of it in Onondaga Lake signifies a greater than 4,500-km range extension for this species. On the basis of the sediment ephippial data, D. curvirostris first appeared in the lake about 1952, reached maximum abundance during the period of peak pollution (1950s-1980s), and then essentially disappeared after 1983 when lake water quality improved. As with the finding of another exotic cladoceran, D. exilis, in Onondaga Lake (Hairston et al. 1999a), it is likely that chemical industry activities on the lakeshores were the original source of invading D. curvirostris, that pollution allowed this species to become established in the lake, and that the reduction in pollution ultimately led to its disappearance from the water column.