Adaptation of Photoreceptor Physiology to Life History Stage in Ontogenetically Migrating Deep-Sea Crustaceans

许多海洋物种面临着一个棘手的问题，因为它们在一生中生活在截然不同的光环境中。这些物种是个体发育的迁徙动物，因为幼体阶段生活在相对明亮的浅水中，而年长的成年阶段可能生活在1000米深的地方，那里光线很少。事实上，关于这两个生命历史阶段如何适应这些截然不同的光环境，人们几乎一无所知。拥有一只在强光和暗光下都能工作的眼睛是不是一个问题，但在这两种情况下，最佳视力设计不是真正的最佳吗？或者，是否有机制允许在不到一年的时间内，将一只在强光下工作良好的眼睛转换为一只在非常暗的光线下工作良好的眼睛？这项建议试图研究深海生物的成体是否比浅水生物的幼体对光更敏感，以及在各种甲壳类物种中产生这些敏感性差异的机制(如果存在的话)。这将通过结合生理、分子和组织学技术来检测它们眼睛的各种特征，即它们对光的敏感度、它们的结构和光学以及它们的视觉色素。其中许多甲壳类物种是支持主要商业渔业的海洋食物网的主要组成部分，了解它们是否以及如何适应不同的光环境对于模拟其光环境的变化(如污染导致的水透明度变化)可能对其分布模式产生什么影响至关重要。此外，还将对热液喷口虾巨大的背眼进行检查。到目前为止，所有收集到的热液喷口虾的背部眼睛都显示出明显的光损伤迹象。这引起了人们的担忧，即这些眼睛可能是被光线摧毁的非常敏感的结构，并导致人们认为，在经过严格研究的喷口地点，大多数喷口虾因反复暴露在ROV和潜水器中而永久失明。不幸的是，所有被检查的虾都是在极其明亮的人造灯光下收集的，无法确定所有的光损害是在收集过程中发生的，还是由于过去暴露在人造灯光下的原因。通过新设计的收集技术，可以在不暴露于光的情况下收集这些物种，这项建议试图研究从未暴露于光的背部眼睛的敏感性，以及在实验室反复暴露于泛光灯照明的累积影响。这项研究将提供数据，以解决是否需要划定保护区类型的禁止访问区的问题，以便研究使生态系统中的大多数流动生物失明的生态影响。

A number of marine species have a difficult problem to deal with, in that they live in vastly different light environments during the course of their lifetimes. These species are ontogenetic migrators, in that the young juveniles stages live in relatively brightly lit shallow waters, while the older adult stages may live 1000 m deeper, where there is very little light. Virtually nothing is known about how these two life history stages adapt to these dramatically different light environments. Is it a matter of possessing an eye that works in both bright and dim light, but isn't really the best design for optimal vision under either condition? Or are there mechanisms in place that allow for the conversion of an eye designed to function well in bright light to one that functions well in very dim light, over a timeframe of less than a year? This proposal seeks to examine whether deep-living adults are substantially more sensitive to light than shallow-living juveniles, as well as the mechanisms involved in producing these sensitivity differences, if they exist, in a variety of crustacean species. This will be done by using combination of physiological, molecular and histological techniques to examine various characteristics of their eyes, namely their sensitivity to light, their structure and optics, and their visual pigments. Many of these crustacean species are major components of the oceanic food webs that support the major commercial fisheries, and understanding whether and how they adapt to different light environments is critical to modeling what effect a change in their light environment (such as a change in water clarity due to pollution) may have on their distribution patterns. In addition, the enormous dorsal eye of hydrothermal vent shrimp will be examined. To date, the dorsal eyes of all the hydrothermal vent shrimp that have been collected show signs of significant light damage. This has given rise to the concern that these eyes may be remarkably sensitive structures that are being destroyed by light, and led to the suggestion that a majority of the vent shrimp at heavily studied vent sites are being permanently blinded by repeated exposure to ROV and submersible. Unfortunately, all the shrimp that have been examined have been collected under extremely bright artificial lights, and it has been impossible to determine whether all the light damage occurred during the collection, or was due to some past exposure to artificial lights as well. With newly designed collecting techniques that will allow collection of these species without exposure to light, this proposal seeks to study the sensitivity of a dorsal eye that has never been exposed to light, as well as the cumulative effects of repeated exposure to floodlight illumination in the laboratory. This research will provide data to address the issue of whether sanctuary type no-visit zones need to be designated in order to study the ecological impact of blinding a majority of the mobile organisms in an ecosystem.