The diet of the diamond stingray (Hypanus dipterurus) was quantified based on individuals collected monthly from October 2013 to December 2015 on Espiritu Santo Island in the Bahia de La Paz, Mexico. Of the 473 stomachs analysed, 211 (44.6%) contained food. Analysis of the prey-specific index of relative importance indicated that the diet of H. dipterurus was based on infaunal and epibenthic invertebrates, especially the bivalve Solemya spp. (42.2%) and the stomatopod Nannosquilla raymanningi (7.7%). Statistical analyses of the diet considering sex, age, maturity stage and interactions between sex, age and season indicated that older females consumed more polychaetes in the cold (November–April) season and that younger females consumed more stomatopods and bivalves in the warm (May–October) season. The feeding strategy of the species is specialised on three prey categories (bivalves, polychaetes and stomatopods), with low trophic niche breadth values. The calculated trophic level indicated that the diamond stingray is a secondary consumer and mesopredator. We conclude that the diamond stingray does not maintain a redundant trophic function with sympatric elasmobranchs in the study area, and is therefore likely a key prey density-regulator functioning to link energy derived from lower to upper trophic levels within the southern Gulf of California.

中文翻译：

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年龄、成熟阶段、性别和季节性对加利福尼亚湾南部钻石黄貂鱼（Hypanus dipterurus）摄食策略的影响

钻石黄貂鱼（Hypanus dipterurus）的饮食是根据 2013 年 10 月至 2015 年 12 月在墨西哥巴伊亚德拉巴斯的圣埃斯皮里图岛每月收集的个体进行量化的。在分析的 473 个胃中，211 个 (44.6%) 含有食物。对相对重要性的猎物特异性指数的分析表明，双翅目的饮食是基于底栖动物和底栖无脊椎动物，尤其是双壳类 Solemya spp。(42.2%) 和 stomatopod Nannosquilla raymanningi (7.7%)。考虑性别、年龄、成熟阶段以及性别、年龄和季节之间相互作用的饮​​食统计分析表明，老年雌性在寒冷（11 月至 4 月）季节消耗更多的多毛类动物，而年轻雌性在温暖季节（5 月）消耗更多的口足类动物和双壳类动物。 – 十月）季节。该物种的摄食策略专门针对三个猎物类别（双壳类、多毛类和口足类），具有较低的营养生态位宽度值。计算出的营养水平表明，钻石黄貂鱼是次要消费者和中掠食者。我们得出的结论是，钻石黄貂鱼在研究区域内没有与同域弹鳃保持冗余的营养功能，因此很可能是一个关键的猎物密度调节剂，其功能是将来自加利福尼亚湾南部的低营养级和高营养级的能量联系起来。