ABSTRACT: Syngnathids are vulnerable ovoviviparous fishes in which males undergo repeated brooding within a reproductive season. The isotopic effects of diet on both breeders (pooled sexes) and parent-egg transmission have been demonstrated in a few fish species but never in syngnathids. Quantifying isotopic changes due to diet is necessary to assess parent-newborn conversions and to estimate accurate trophic enrichment factors (TEF). We assessed the isotopic (δ¹³C and δ¹⁵N) effects of 3 experimental diets on TEFs in seahorse Hippocampus guttulatus breeders and isotopic inheritance. Our results suggest that H. guttulatus follows an income-capital continuum pattern for parent-egg transmission. The isotopic variability in diets for breeders and the resulting experimentally derived TEFs were compared with fixed TEFs from reviews to estimate their impact on the relative contribution of potential prey sources in syngnathids from the Cíes archipelago (Atlantic Islands National Park, NW Spain). We estimated source contributions using stable isotope mixing models (SIMMs) by combining prey sources into ecologically informative groups and incorporating informative priors. We demonstrate that (1) most frequently used TEFs from reviews might not be suitable for all fish species, particularly syngnathids, and (2) dietary source variability has a great effect on source contribution estimates. This study is also the first to provide specific TEFs for syngnathids.

中文翻译：

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饮食对繁殖者的影响和突触鱼类的遗传：同位素实验所得数据在田间研究中的应用

摘要：Syngnathids是易受感染的卵生鱼，其中雄鱼在生殖季节内反复繁殖。日粮对种鱼（成年雌性）和亲代卵传播的同位素影响已经在少数鱼类中得到证实，但在辛那吉特鱼类中却没有。量化因饮食引起的同位素变化对于评估父母-新生儿的转化和估计准确的营养富集因子（TEF）是必要的。我们评估了同位素（δ ¹³ C和δ ¹⁵ N）在海马上毒性当量因子3个实验饮食的作用海马guttulatus育种者和同位素继承。我们的结果表明，H。guttulatus遵循收入-资本连续体模式进行亲代蛋传播。通过审查比较了育种者日粮中的同位素变异性和由此产生的实验得出的TEF与固定TEF，以评估它们对来自群岛群岛（大西洋群岛国家公园，西班牙西北部）的合胞体中潜在猎物来源的相对贡献的影响。我们通过将猎物来源分为生态信息丰富的群体并纳入信息丰富的先验条件，使用稳定的同位素混合模型（SIMM）估算了来源贡献。我们证明（1）评论中最常用的TEF可能并不适合所有鱼类，尤其是突触类鱼类；（2）饮食来源的可变性对来源贡献估算有很大影响。这项研究也是第一个为突触类提供特定TEF的研究。