DISSERTATION RESEARCH: The food matrix mediates carotenoid tradeoffs in a reverse-dimorphic cichlid

脊椎动物的大多数红色、橙色和黄色是类胡萝卜素色素的结果。脊椎动物不能合成类胡萝卜素，必须从饮食中获得类胡萝卜素，但类胡萝卜素在减少氧化应激和支持免疫系统方面也发挥着重要作用。类胡萝卜素权衡假说预测，当饮食中类胡萝卜素受到限制时，动物必须牺牲色素或免疫力。许多已发表的关于类胡萝卜素权衡假说的研究引用了饮食类胡萝卜素具有局限性的假设，但这一说法在很大程度上是未经检验的。同样地，对于具有逆性二色性的物种的雌性类胡萝卜素的权衡也知之甚少，即雌性的颜色比雄性更鲜艳的物种。雌性对类胡萝卜素还有额外的竞争需求，即色素可以被合并到蛋黄中并传递给后代。这项建议试图利用实验室和田间研究相结合的方法，通过建立一个统计模型来预测类胡萝卜素在野外的可获得性和分配，从而了解类胡萝卜素的吸收、性着色和身体维持之间的复杂关系。这项拟议的研究将使用有罪的慈鱼(Amatitlania NigroFasciata)来解决这些问题，这是一种研究得很好的中美洲鱼类，雌性鱼的腹部着色基于类胡萝卜素。拟议的研究将利用实地工作设计一个联立方程模型，以此为基础，未来实验室研究环境中类胡萝卜素的可获得性与类胡萝卜素色素物种的食物基质之间的相互作用。开发类胡萝卜素吸收的统计模型将使其他研究人员能够将他们关于类胡萝卜素权衡假说的工作置于理论背景下，并对观赏鱼和食用鱼养殖的鱼类健康产生影响，这两个行业在美国都有数百万美元的收入。

Most red, orange and yellow coloration in vertebrate animals is the result of carotenoid pigments. Vertebrates cannot synthesize carotenoids and instead must obtain them from their diet, but carotenoids also play important roles in reducing oxidative stress and supporting the immune system. The carotenoid trade-off hypothesis predicts that when dietary carotenoids are limited, animals must sacrifice coloration or immunity. Many published studies of the carotenoid trade-off hypothesis cite the assumption that dietary carotenoids are limiting, but this statement is largely untested. Likewise, little is known about carotenoid trade-offs in females of species with reversed sexual dichromatism, i.e. species in which females are more brightly colored than males. Females have an additional competing need for carotenoids, namely that the pigments can be incorporated into egg yolk and passed on to their offspring. This proposal seeks to use a combination of laboratory and field studies to understand the complex relationship between carotenoid absorption, sexual coloration, and somatic maintenance in pigmented females by developing a statistical model to predict carotenoid availability and allocation in the wild. The proposed study will address these questions using the convict cichlid (Amatitlania nigrofasciata), a well-studied Central American fish in which females have carotenoid-based ventral coloration. The proposed study would use field work to design a simultaneous equations model on which to base future laboratory studies of the interaction between environmental carotenoid availability and the food matrix in carotenoid-pigmented species. Development of a statistical model for carotenoid absorption will allow other researchers to place their work on the carotenoid trade-off hypothesis into a theoretical context, in addition to having implications for fish health in ornamental and food fish farming, both multi-million dollar industries in the United States.