The relative roles of physical and biological factors in larval supply and recruitment of marine benthic invertebrates

物理和生物因素在海洋底栖无脊椎动物幼体供应和招募中的相对作用

• 批准号: 222932-2006
• 负责人: Metaxas, Anna
• 金额: $ 2.03万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=335125
• 关键词: relative; roles; physical; biological; factors

Invertebrate organisms that live on the bottom of the ocean, such as crabs, lobsters, clams and sea urchins, have complex life cycles. As adults, they live and feed on the bottom, but they release sperm and eggs in the water column, and fertilization occurs externally.  The produced embryos develop into larvae and may spend from a few hours to months in the water column, being carried around by currents.  After they mature, larvae move near the bottom, attach to it and, following a sequence of morphological and physiological changes, turn into juveniles.  These juveniles look and live on the bottom like young adults. Obviously, the number of new recruits that return to the adult populations will depend on the number of larvae that survive the period spent in the water column. Thus, understanding the processes that occur at the larval stage is important for the successful management of invertebrate nuisance species and fisheries, and development of aquacultural practices. Although, we understand the factors that affect survival of adults because of their relatively large size and the accessibility of their habitat, we know little about larval and juvenile survival. We will study factors that regulate larval and juvenile survival.  We will examine how larvae respond to cues in their environment, such as water flow, temperature gradients and the presence of predators, in the laboratory.  We will also study the ecology of early life history stages in two alien species in Nova Scotia. We will measure the effects of the interaction of juveniles of the alien green crab with those of native crab species on food consumption and growth rates. For a bryozoan invasive, we will measure larval supply by sampling larvae in the water and on the bottom at different sites throughout the year. We will also measure rates of colonization on algae and environmental characteristics, such as temperature and currents.  In laboratory experiments, we will observe larvae grow under different temperatures and measure how larvae behave under different current flows and thermal gradients. Lastly, using new technologies, we will measure larval abundance and colonization rate after disturbance in the deep sea using the cabled observatory NEPTUNE in the NE Pacific.

生活在海底的无脊椎动物，如螃蟹、龙虾、文蛤和海胆，有着复杂的生命周期。作为成虫，它们在水底生活和觅食，但它们在水柱中释放精子和卵子，受精在外部进行。这些胚胎发育成幼虫，可能会在水柱中度过几个小时到几个月，被水流携带。当它们成熟后，幼虫移动到水底附近，附着在水底，并随着一系列形态和生理变化，变成幼虫。这些幼虫看起来和生活在水底，就像年轻的成年人一样。显然，回到成年种群的新兵数量将取决于在水柱中度过的那段时间存活的幼虫数量。因此，了解幼体阶段发生的过程对于成功管理无脊椎动物有害物种和渔业以及发展水产养殖实践非常重要。尽管我们了解影响成虫生存的因素，因为它们的体型相对较大，而且它们的栖息地很容易获得，但我们对幼虫和幼虫的生存知之甚少。我们将研究调节幼虫和幼虫存活的因素。我们将在实验室中检查幼虫对其环境中的线索的反应，如水流、温度梯度和捕食者的存在。我们还将研究新斯科舍省两个外来物种早期生活史阶段的生态。我们将测量外来青蟹幼体与本地蟹种幼体之间的相互作用对食物消耗和生长速度的影响。对于苔藓虫入侵，我们将通过全年在水中和不同地点的海底采样幼虫来测量幼虫供应。我们还将测量藻类的定殖率和环境特征，如温度和洋流。在实验室实验中，我们将观察幼虫在不同温度下的生长，并测量幼虫在不同水流和温度梯度下的行为。最后，利用新技术，我们将利用东北太平洋的海王星有线观测站测量深海扰动后的幼虫丰度和定殖率。