Isotope analysis reveals proportional change and site-selection variation of river- and lake-produced eggs of a landlocked migratory fish.
Isotope analysis reveals proportional change and site-selection variation of river- and lake-produced eggs of a landlocked migratory fish.
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同位素分析揭示了内陆洄游鱼类在河流和湖泊产卵的比例变化和地点选择变化。
DOI：
10.1111/jfb.14200
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发表时间：
2019
影响因子：
2
通讯作者：
A.
中科院分区：
文献类型：
--
作者：
Sawada;H.;Shigeta;K.;Kawakami;M.;Yuma;M.;Maruyama;A.
根据琵琶湖及其支流捕食性生物δ15N和δ13C值的不同，采用稳定同位素分析方法，监测了日本琵琶湖水系内陆性两栖鱼类AYU(Plecoglossus Altivelis Altivelis)河产和湖产卵比例的变化。在3个月的繁殖期，产卵的δ-15N值随时间的延长而降低。这一结果表明，在一个繁殖季节内，湖中的成鱼卵巢中的卵的δ15N值明显高于支流中的卵，这表明在一个繁殖季节内，湖泊产的卵向河流产的卵转变。这一解释也被产卵的δ13C值的变化所支持。此外，较低的δ15N和较高的δ13C值的卵倾向于在较小的可变深度产卵，这表明产卵的雌性在较窄的范围内选择产卵地点。我们的结论是，产卵的稳定同位素比率可以作为不同食物链相对贡献的指标，并可以比较不同类型鸡蛋的繁殖特征。
Changes in the proportions of river‐ and lake‐produced eggs of a landlocked amphidromous fish, ayu (Plecoglossus altivelis altivelis) in the Lake Biwa water system, Japan, were monitored by stable isotope analysis, based on different δ15N and δ13C values of prey organisms between the lake and its tributaries. During the 3 month reproduction season, the δ15N values of spawned eggs decreased with time. This result implies that there was a shift from lake‐produced eggs to river‐produced eggs within a reproductive season, based on the observation that adult fish in the lake had previously been shown to have eggs with distinctly higher δ15N values in their ovaries than those in the tributaries. This explanation was also supported by the change in δ13C values of the spawned eggs. Furthermore, eggs with lower δ15N and higher δ13C values tended to be spawned at less variable depths, suggesting that females spawning river‐produced eggs selected the spawning sites from a narrower range. We conclude that stable isotope ratios of spawned eggs can be indicators of the relative contributions of different food chains and can enable comparisons of reproductive characteristics between types of egg.