ABSTRACT: Understanding ontogenetic linkages among fish habitats is critical for conservation of fish populations and the ecosystems on which they rely. Natural tags such as stable isotopes are effective for investigating ecological questions regarding fish movement and habitat use. We analyzed stable isotopes from sequentially deposited laminae of hogfish Lachnolaimus maximus eye lenses from the eastern Gulf of Mexico (eGOM) to investigate trophic and geographic changes across individual life histories. We documented evidence of 1 to 2 step trophic level increases through δ¹⁵N increases. We also observed depth separation at the juvenile stage, evidenced by δ¹³C variation early in life. These results suggest that adult hogfish in deeper habitats likely inhabited deeper juvenile habitats (i.e. nearshore reefs), while adult hogfish inhabiting shallower adult habitats likely used shallower juvenile habitats (i.e. estuaries). This novel finding for eGOM hogfish contradicts prior literature that solely discusses seagrass as juvenile habitat. We used muscle tissue isotopes to characterize juvenile hogfish habitats and linear discriminant function analysis (LDA) to determine the habitats previously inhabited by adults in this study. The LDA revealed Cedar Key as the most used juvenile hogfish habitat in this study, but more evidence is needed to determine its status as a nursery. This study provides the first evidence for ontogenetic migration of individual hogfish using natural tags as tracers and demonstrates a mechanism for identifying juvenile habitats based on eye lens stable isotope analysis. Identifying ontogenetic patterns and habitat use can help to better conserve stocks and essential fish habitats.

中文翻译：

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猪鱼的生活史：通过稳定同位素分析得出的营养生长和幼体栖息地的不同利用

摘要：了解鱼类栖息地之间的遗传联系对于保护鱼类种群及其赖以生存的生态系统至关重要。诸如稳定同位素之类的天然标签可有效地调查有关鱼类运动和栖息地使用的生态问题。我们分析了来自墨西哥湾东部（eGOM）的猪鱼Lachnolaimus maximus眼透镜的依次沉积的薄片的稳定同位素，以研究个体生活史中的营养和地理变化。我们通过δ记载的1至2个步骤营养水平增加的证据^15个N增加。在幼年期我们还观察到的深度的分离，通过δ证明¹³C早年生活中的变异。这些结果表明，在较深栖息地的成年猪鱼可能栖息在较深的少年栖息地（即近岸珊瑚礁），而在较浅栖息地的成年猪鱼可能使用较浅的少年栖息地（即河口）。eGOM猪鱼的这一新发现与仅讨论海草作为未成年人栖息地的先前文献相矛盾。我们使用肌肉组织同位素来表征幼年猪鱼的栖息地，并使用线性判别函数分析（LDA）来确定以前在该研究中成人所居住的栖息地。LDA揭示了Cedar Key是该研究中最常用的幼年猪鱼栖息地，但是需要更多的证据来确定其作为苗圃的地位。这项研究为使用天然标签作为示踪剂的个体猪的个体遗传学迁移提供了第一个证据，并展示了基于眼晶状体稳定同位素分析确定幼体栖息地的机制。识别个体发育模式和栖息地使用可以帮助更好地保护种群和重要的鱼类栖息地。