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: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=393367
• 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生物，如螃蟹、龙虾、蛤蜊和海胆，有着复杂的生命周期。成虫在水底生活和觅食，但在水柱中释放精子和卵子，受精在外部进行。产生的胚胎发育成幼虫，在水柱中呆上几个小时到几个月，被水流带着到处走。成熟后，幼虫移近水底，附着在水底，经过一系列形态和生理变化，变成幼鱼。这些幼鱼看起来和生活在海底就像年轻的成年人。显然，回到成年种群的新成员的数量将取决于在水柱中生存的幼虫的数量。因此，了解发生在幼虫阶段的过程是非常重要的无脊椎动物滋扰物种和渔业的成功管理，以及水产养殖实践的发展。虽然，我们了解的因素，影响成人的生存，因为他们相对较大的大小和他们的栖息地的可达性，我们知道的幼虫和少年的生存。我们将研究调节幼虫和幼体生存的因素。我们将在实验室中研究幼虫如何对环境中的线索作出反应，例如水流，温度梯度和捕食者的存在。我们还将研究新斯科舍省两种外来物种的早期生活史阶段的生态学。我们将测量外来绿色蟹幼蟹与本地蟹种的相互作用对食物消耗和生长速率的影响。对于一个苔藓虫入侵，我们将测量幼虫供应抽样幼虫在水中和底部在不同的地点在全年。我们亦会测量藻类在水中的定殖率，以及环境的特徴，例如温度和水流。在实验室实验中，我们会观察幼虫在不同温度下的生长，以及测量幼虫在不同水流和温度梯度下的行为。最后，我们将利用新技术，利用东北太平洋的有线观测台NEPTUNE测量深海扰动后的幼虫丰度和定殖率。