Balancing the demands of physiological processes: Decapod crustacean feeding and digestion in hypoxia

平衡生理过程的需求：十足目甲壳类动物在缺氧条件下的摄食和消化

• 批准号: RGPIN-2016-04826
• 负责人: Mcgaw, Iain
• 金额: $ 2.26万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683763
• 关键词: Balancing; demands; physiological; processes; Decapod

Dissolved oxygen levels in coastal areas have changed more than any other environmental variable during the past few decades, leading to widespread hypoxia. Crustaceans are among the most sensitive organisms to hypoxia and could therefore act as important indicator species of a healthy environment. Knowledge of their behavioural and physiological responses will be invaluable when predicting long-term effects of hypoxia on benthic communities. In general crustaceans respond to a decline in oxygen tension by increasing ventilation rate in an attempt to maintain a stable oxygen (O2) uptake, at a certain level they are unable to maintain O2 uptake and thereafter it drops in line with that of the environment. All organisms must feed in order to survive and the subsequent digestion of a meal leads to a general increase in metabolism termed the specific dynamic action (SDA). Thus current trends in hypoxia will reduce the available dissolved O2 at a time when organisms need to uptake more O2 for digestive processes.**** This research will investigate how several species of decapod crustaceans (rock crab, green crab, lobster, Dungeness crab) with differing ability to deal with hypoxia balance cardiorespiratory variables (respiration, cardiac function, blood chemistry) when they feed and digest in hypoxia. If animals are unable to maintain O2 uptake during hypoxia we will determine if they can slow or halt digestive processes (mechanical costly” physiological mechanisms. A Loligo shuttlebox® will be used to determine if feeding status alters O2 preference. The apparatus allows animals to choose between two O2 regimes while a computer tracks movement. By monitoring speed of movement, O2 choice and feeding activity we will be able to determine if fed and starved animals have different O2 preferences, or if trade-off occurs whereby with increasing starvation time an animal will be more likely expend energy entering into low O2 in order to obtain a food reward.**** Ecophysiology has had a renaissance in the last decade and this integrative approach studying the connections between whole animal physiology and behaviour is important when investigating interactions between the animal and its environment. Historically scientists carried out experiments under controlled conditions where feeding was carefully regimented, the results of this research will show how multiple stressors may interact in more natural conditions. In light of climate change and the exponential increase in hypoxia the results of this research will not only be of interest to the scientific community, but will also be important for environmental resource managers in understanding potential responses of communties to environmental change.****

在过去的几十年里，沿海地区溶解氧水平的变化超过任何其他环境变量，导致广泛的缺氧。甲壳类动物是对缺氧最敏感的生物之一，因此可以作为健康环境的重要指示物种。在预测缺氧对底栖群落的长期影响时，了解它们的行为和生理反应将是非常宝贵的。一般来说，甲壳类动物通过增加通风率来应对氧张力的下降，以试图维持稳定的氧气 (O2) 吸收，在一定水平上，它们无法维持 O2 吸收，此后它会随着环境的变化而下降。所有生物体都必须进食才能生存，随后的膳食消化会导致新陈代谢的普遍增加，称为特定动态作用（SDA）。因此，当生物体需要吸收更多的氧气来进行消化过程时，当前的缺氧趋势将减少可用的溶解氧气。**** 这项研究将调查几种具有不同能力的十足目甲壳类动物（石蟹、青蟹、龙虾、珍宝蟹）在进食和消化时如何平衡缺氧的心肺变量（呼吸、心脏功能、血液化学）。 缺氧。如果动物在缺氧期间无法维持 O2 吸收，我们将确定它们是否可以减缓或停止消化过程（机械成本高昂的“生理机制”。Loligo Shuttlebox® 将用于确定喂养状态是否会改变 O2 偏好。该设备允许动物在两种 O2 模式之间进行选择，同时计算机跟踪运动。通过监测运动速度、O2 选择和喂养活动，我们将能够确定喂食和饥饿动物是否具有不同的 O2 偏好，或者如果发生权衡，随着饥饿时间的增加，动物更有可能消耗能量进入低氧气环境以获得食物奖励。****生态生理学在过去十年中得到了复兴，这种研究整个动物生理学和行为之间联系的综合方法在研究动物与其环境之间的相互作用时非常重要。历史上，科学家们在严格控制喂养的受控条件下进行了实验，结果 这项研究的一部分将展示多种压力源如何在更自然的条件下相互作用。鉴于气候变化和缺氧指数增加，这项研究的结果不仅会引起科学界的兴趣，而且对于环境资源管理者了解社区对环境变化的潜在反应也很重要。****