Habitat Severity and Internal Ice in Antarctic Notothenioid Fishes

Notothenioid鱼类生活在世界上最冷的海洋沃茨周围的南极洲和进化的策略，以避免冻结。过去的研究表明，大多数南极鱼产生特殊的抗冻蛋白，防止进入体内的冰晶生长。虽然这些蛋白质有助于防止个体被生长的冰晶杀死，但目前还不清楚这些鱼如何避免这些小冰晶随着时间的推移在其组织内积累。本计画将观察南极洲麦克默多海峡不同栖息地中，冰晶累积与鱼类栖息地的严酷程度及鱼类行为的关系。研究人员将在不同的野外地点收集鱼类和海洋观察结果，这些地点涵盖了一系列栖息地的温度和冰冷程度。研究人员将在麦默多站附近安装一个水下海洋观测站，其中包括一个高清摄像机和水听器。该观测站将允许持续监测海洋条件和鱼类行为，这将有助于解释有助于体内冰的获取和积累的条件和行为。来自观测站的声学和视频数据将提供给其他科学家和公众。该项目将促进对极端寒冷环境中生命面临的许多挑战的理解。这项工作延续了一系列调查，发现了潜在的医疗和食品防腐应用。在实验室中已经进行了数百项抗冻蛋白（AFP）结构-功能研究，为AFP-冰相互作用提供了基本的物理理解。然而，AFP如何在鱼类及其环境范围内发挥作用还远不清楚。这个项目将通过量化内部冰晶的获得、积累和损失来了解南极鱼的防冻机制和策略。具体来说，目标是确定栖息地的严重程度（由冰冷，海水温度和过冷水的流行程度定义）和鱼类行为是否以及如何影响其组织中冰晶的丰度。四个地点在麦克默多声音与不同程度的栖息地的严重性将进行采样的海洋条件和鱼类组织内的冰晶计数。研究人员将使用一种新技术来计算脾脏冰晶的数量，扩展并简化以前的方法。在项目期间，将在四个地点部署环境数据记录仪，以提供环境状况的背景和实时评估。麦默多站附近的一个海洋观测站将提供海洋条件的全年、实时和档案记录、锚冰生长和冰生物相互作用的现场视频观测、水声记录，并作为扩大麦克默多海峡与监测过冷水沃茨和海洋信息有关的科学基础设施的概念验证。

Notothenioid fishes live in the world's coldest marine waters surrounding Antarctica and have evolved strategies to avoid freezing. Past studies have shown that most Antarctic notothenioids produce special antifreeze proteins that prevent the growth of ice crystals that enter the body. While these proteins help prevent individuals from being killed by growing ice crystals, it is unclear how these fish avoid the accumulation of these small ice crystals inside their tissues over time. This project will observe how ice crystal accumulation relates to the harshness of the fish's habitat and the fish's behavior within different habitats of McMurdo Sound, Antarctica. The researchers will collect fishes and ocean observations at different field sites that cover a range of habitat severity in terms of temperature and iciness. Researchers will install an underwater ocean observatory near McMurdo Station which will include a HD video camera and hydrophone. The observatory will allow continuous monitoring of ocean conditions and fish behavior that will help explain the conditions and behaviors that contribute to the acquisition and accrual of ice inside the body. Acoustic and video data from the observatory will be available to other scientists and to the public. The project will advance understanding of the many challenges life faces in extreme cold environments. This work continues a line of inquiry that has resulted in the discovery of potential medical and food preservation applications. Hundreds of antifreeze protein (AFP) structure-function studies have been conducted in the laboratory, providing a basic physical understanding of the AFP-ice interaction. How AFPs function within fishes and their range of environments, however, is far from clear. This project will provide an understanding of notothenioid's freezing avoidance mechanisms, and strategies by quantifying the acquisition, accumulation, and loss of internal ice crystals. Specifically, the goal is to determine if and how habitat severity (as defined by iciness, seawater temperature, and prevalence of supercooled water) and fish behavior influence the abundance of ice crystals in their tissues. Four locations in the McMurdo Sound with different levels of habitat severity will be sampled for oceanographic conditions and ice crystal count within fish tissues. Researchers will use a new technique to count the number of splenic ice crystals, expanding on and simplifying previous methods. Environmental data loggers will be deployed for the duration of the project at the four sites to provide context and real-time assessment of environmental conditions. An oceanographic observatory near McMurdo Station will provide year-round, real-time and archival records of oceanographic conditions, in situ video observations of anchor ice growth and ice-organism interactions, hydroacoustic recordings, and serve as proof-of concept for expanding scientific infrastructure in McMurdo Sound related to monitoring of supercooled waters and oceanographic information.