Natural Inducers of Larval Settlement and Metamorphosis Associated With Mangrove Leaves: Identity and The Role of Bacteria In Their Production.

与红树林叶子相关的幼虫沉降和变态的自然诱导物：细菌的身份和在其生产中的作用。

• 批准号: 9108074
• 负责人: William Fitt
• 金额: $ 6.8万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-15 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9108074&HistoricalAwards=false
• 关键词: Natural; Inducers; Larval; Settlement; Metamorphosis

Marine invertebrate species often have life cycles involving planktonic larvae which must settle on benthic substrates before they metamorphose into the adult form. Such species include edible shellfish likde mussels, oysters and abalone, as well as fouling organisms such as barnacles, hydroids and bryazoans. The process of settlement and metamorphosis is not random. Larvae of many, if not most of the species investigated respond to specific chemicals associated with their adult environment. Relatively little is known about these "natural" cues, and only a few have been either partially or completely identified. This study will focus on identifying and documenting the origin of the natural chemical cues of settlemlent and metamorphosis of planulae larvae of the "upside down" jellyfish Cassiopea xamachana. Preliminary evidence shows that the larvae of this species settle preferentially on old, degrading mangrove leaves. Larvae appear to respond to soluble chemicals released from the leaf, either diffusing directly from the leaf or the result of bacterial action during decomposition. The role of bacteria in producing specific cues for the settlement of larvae will be determined. The fact that another genetic entity (e.g. bacteria can play an integral role in the life cycle a different species is more common in nature than originally thought. Larvae of jellyfish are relatively simple animals, compared with more complicated "higher" invertebrates such as shellfish. Therefore the cellular, molecular and physiological mechanisms in settlement and metamorphosis may be easier to elucidate and provide a "model" for other invertebrate species.//

海洋无脊椎动物的生命周期通常包括浮游生物的幼虫，它们必须在底栖基质上定居，然后才能蜕变成成虫。这些物种包括可食用贝类，如贻贝、牡蛎和鲍鱼，以及藤壶、水螅和苔藓虫等污染生物。沉降和变形的过程不是随机的。许多（如果不是大多数）被调查物种的幼虫对与它们成虫环境相关的特定化学物质有反应。相对而言，我们对这些“自然”线索所知甚少，只有少数被部分或完全确定。本研究的重点是确定和记录“倒立”水母（Cassiopea xamachana）浮叶幼虫沉降和蜕变的自然化学线索的来源。初步证据表明，该物种的幼虫优先定居在老的、退化的红树林树叶上。幼虫似乎对从叶子中释放的可溶性化学物质有反应，这些化学物质要么是直接从叶子中扩散出来的，要么是分解过程中细菌作用的结果。将确定细菌在产生幼虫定居的特定线索方面的作用。另一种遗传实体（例如细菌）可以在不同物种的生命周期中发挥不可或缺的作用，这一事实在自然界中比最初想象的更为普遍。与贝类等更复杂的“高级”无脊椎动物相比，水母的幼虫是相对简单的动物。因此，在沉降和变态过程中的细胞、分子和生理机制可能更容易阐明，并为其他无脊椎动物提供“模型”。//