Ontogenetic changes in diet and habitat use in green sea turtle (Chelonia mydas) life history
Ontogenetic changes in diet and habitat use in green sea turtle (Chelonia mydas) life history
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DOI：
10.3354/meps07440
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发表时间：
2008-01-01
影响因子：
2.5
通讯作者：
Limpus, Colin J.
中科院分区：
文献类型：
--
作者：
Arthur, Karen E.;Boyle, Michelle C.;Limpus, Colin J.
绿海龟是一种濒危的、长寿的海洋爬行动物，它们在发育过程中表现出饮食和栖息地利用的个体发生变化。在它们生命的早期阶段，西南太平洋的绿海龟幼崽栖息在远洋区，在那里它们以神经物质为食。在大约44厘米的弯曲甲壳长，他们招募到近海觅食栖息地，在那里他们成为主要的草食性。在这项研究中，我们研究了绿海龟表皮组织稳定同位素（δ C-13和δ N-15）组成在其整个生活史中的变化，以研究这种在西南太平洋绿海龟种群中发生的饮食和栖息地的个体发生转变。最近被招募到澳大利亚莫尔顿湾觅食地的海龟，与所有其他生活史组相比，其δ N-15同位素特征明显较高，而与除远洋幼龟外的所有年龄组相比，δ C-13同位素特征明显较低。与幼龟和小幼龟相比，成龟和大幼龟具有相似的同位素特征，C-13含量均显著富集。这些结果支持了先前的观察结果，即远洋幼龟在不同的栖息地觅食，比在浅海环境中捕获的海龟营养水平更高。这是第一个从觅食生态学角度捕捉绿海龟整个生活史的研究，并支持之前在绿海龟的传统饮食和行为研究中观察到的个体发生转变。
Green turtles Chelonia mydas are endangered, long-lived marine reptiles that display an ontogenetic shift in diet and habitat use during development. During their early life stage, juvenile green turtles in the southwestern Pacific inhabit the pelagic zone where they feed omnivorously on neustonic material. At approximately 44 cm curved carapace length they recruit to inshore foraging habitats where they become primarily herbivorous. In this study we investigate the change in stable isotope (delta C-13 and delta N-15) composition of green turtle epidermal tissue throughout their life history to examine this ontogenetic shift in diet and habitat as it occurs in a southwestern Pacific green turtle population. Turtles that had recently recruited to foraging grounds in Moreton Bay, Australia had significantly higher delta N-15 isotopic signatures when compared with all other life history groups examined and significantly lower delta C-13 when compared with all age classes other than pelagic juveniles. Adult and large immature turtles had similar isotopic signatures and were both significantly enriched in C-13 when compared with hatchlings and small immature turtles. These results support previous observations that suggest pelagic juveniles are foraging in a different habitat and at a higher trophic level than turtles captured in the neritic environment. This is the first study to capture the entire life history of green turtles in terms of foraging ecology and supports the ontogenetic shift previously observed in traditional diet and behavioral studies of green turtles.