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

大多数脊椎动物的红色、橙色和黄色都是类胡萝卜素的结果。脊椎动物不能合成类胡萝卜素，必须从饮食中获取，但类胡萝卜素在减少氧化应激和支持免疫系统方面也起着重要作用。类胡萝卜素权衡假说预测，当饮食中的类胡萝卜素受到限制时，动物必须牺牲颜色或免疫力。许多已发表的类胡萝卜素权衡假说的研究引用了饮食类胡萝卜素是限制的假设，但这种说法在很大程度上未经检验。同样地，对于性别二色性逆转的物种（即雌性比雄性颜色更鲜艳的物种）的雌性类胡萝卜素的权衡，我们所知甚少。雌性对类胡萝卜素有额外的竞争需求，也就是说，这种色素可以融入蛋黄并传递给它们的后代。本研究旨在结合实验室和实地研究，通过建立一个统计模型来预测野生环境中类胡萝卜素的可用性和分配，以了解有色素的雌性动物的类胡萝卜素吸收、性着色和体细胞维持之间的复杂关系。拟议的研究将利用罪犯鲷（Amatitlania nigrofasciata）来解决这些问题，这是一种经过充分研究的中美洲鱼类，雌性鱼的腹部有基于类胡萝卜素的颜色。拟议的研究将利用实地工作来设计一个联立方程模型，以该模型为基础，对类胡萝卜素色素物种中环境类胡萝卜素可利用性与食物基质之间的相互作用进行未来的实验室研究。类胡萝卜素吸收的统计模型的发展将使其他研究人员能够将他们的工作放在类胡萝卜素权衡假设的理论背景中，除了对观赏鱼和食用鱼养殖中的鱼类健康有影响之外，这两个行业在美国都是数百万美元的产业。

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.