Moving From Sea to Land Via the Freshwater Route: Larval Physiology and Mode of Recruitment in a Freshwater Fiddler Crab

通过淡水路线从海洋移动到陆地：淡水招潮蟹幼虫生理学和招募模式

• 批准号: 0232094
• 负责人: Renae Brodie
• 金额: $ 2.46万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0232094&HistoricalAwards=false
• 关键词: Moving; Sea; Land; Via; Freshwater

In this study, we will develop a molecular method to identify the cryptic larval forms of three fiddler crab species common in salt marsh communities of the southeastern United States. While the adults of these closely related species, Uca minax, Uca pugnax, and Uca pugilator, are among the most studied of salt marsh invertebrates, work on larval and juvenile crabs has been hindered because they are morphologically indistinguishable at these early life stages. Using a fast, inexpensive molecular assay, we will map the distribution of these three species starting in late spring when they begin to enter the mouth of South Carolina's North Inlet estuary after completing larval development in open coastal waters until late fall when the last of the year's young have joined the established adult populations. From this information, we will produce a high-resolution model of the annual invasion of the marsh by Uca crabs. We will determine the timing, position, and degree of penetration by young of the three species into habitats preferentially occupied by their adult counterparts. We will learn if the three species migrate differently, or if their young penetrate all areas equally and differential mortality after settlement determines adult distributions within the estuary. Estimates from the field will be refined with lab-based experiments in which young crabs of the three species will be exposed to sediment from adult habitats under low or high salinity conditions. How young crabs respond to these environmental cues may explain their ability to locate adult habitats.The broader impact of this study lies in the molecular assay that we are developing to differentiate young of these three crab species. Fiddler crabs heavily impact southeastern estuaries by modifying species composition, landscape topography, and water chemistry in areas where they burrow and feed. Also, adult crabs can comprise a large portion of the diets of wetland birds and crab larvae are important prey for small fishes that are eaten by larger fishes exploited by commercial and sport fisheries. Our assay will allow us to assess the stability of marsh ecosystems over time and will be useful in estimating crustacean biodiversity. The development of this assay will eliminate a large hurdle in our understanding of birth, recruitment, and death in the salt marsh by allowing us to investigate the full life cycles of these widely studied crabs in detail for the first time.

在这项研究中，我们将开发一种分子方法来识别美国东南部盐沼社区中常见的三种招潮蟹的神秘幼虫形式。虽然这些密切相关的物种，Uca minax，Uca pugnax和Uca pugilator的成年人是盐沼无脊椎动物中研究最多的，但对幼虫和幼蟹的研究一直受到阻碍，因为它们在这些早期生命阶段的形态无法区分。使用快速，廉价的分子检测，我们将映射这三个物种的分布开始在晚春时，他们开始进入口的南卡罗来纳州的北入口河口后，在开放的沿海沃茨完成幼虫发育，直到晚秋时，最后一年的年轻人已经加入了既定的成年人口。 从这些信息中，我们将产生一个高分辨率的模型，每年入侵的沼泽招潮蟹。我们将确定的时间，位置和程度的三个物种的年轻人进入栖息地优先占据的成年同行的渗透。我们将了解这三个物种的迁移方式是否不同，或者它们的年轻人是否平等地渗透到所有地区，定居后的差异死亡率决定了河口内的成年人分布。将通过实验室实验对实地的估计进行改进，在实验中，三个物种的幼蟹将暴露于低或高盐度条件下成年栖息地的沉积物。幼蟹对这些环境线索的反应可能解释了它们定位成年蟹栖息地的能力。这项研究的更广泛影响在于我们正在开发的区分这三种蟹种幼蟹的分子测定。招潮蟹严重影响东南部河口修改物种组成，景观地形和水化学领域，他们挖洞和饲料。此外，成年蟹可以构成湿地鸟类的大部分食物，蟹幼虫是商业和体育渔业开发的较大鱼类食用的小鱼的重要猎物。我们的分析将使我们能够评估沼泽生态系统的稳定性，随着时间的推移，将是有用的估计甲壳动物的生物多样性。这项试验的发展将消除我们理解盐沼中出生、招募和死亡的一个巨大障碍，使我们能够首次详细调查这些被广泛研究的螃蟹的整个生命周期。