Mechanisms by Which Marine Algae Respond to Environmental Variables Affecting Reproductive Success

[604848 .布劳利]许多海洋物种通过外部受精繁殖。这种繁殖模式可能会导致低水平的受精和招募，因为汹涌的海水会稀释卵子和精子。然而，最近的研究表明，岩藻类藻类（即褐色海藻，是岩石、潮间带和河口的重要组成部分）只有在海水平静时才会感觉到水的运动，并释放卵子和精子。几乎100%的卵子都受精了。拟议的实验将确定这些藻类如何感知水的运动，以及是否在其他几种商业收获的物种或重要的有害物种中发现类似的反应。利用电子显微镜和生理学技术对生殖组织进行研究，将建立从成人体内排出卵子和精子的机械力的基础，以及这些机械力是如何被高水位运动阻挡的。对新英格兰河口自然群落的实地研究将补充实验室工作。这些研究将促进对海洋藻类对影响繁殖成功的环境变量作出反应的机制的理解。这些信息对基础科学家、海洋工程师、海岸带管理人员和海水养殖者都很有用。

9604848 Brawley Many marine species reproduce by external fertilization. This mode of reproduction might be expected to result in low levels of fertilization and recruitment because of the dilution of eggs and sperm by the turbulent sea. Recent work, however, demonstrates that fucoid algae (i.e., brown seaweed's that are important components of rocky, intertidal zones and estuaries) sense water motion and release eggs and sperm only when the sea is calm. Nearly 100% of their eggs are fertilized. The proposed experiments will determine how these algae sense water motion and whether similar responses are found in several other species that are harvested commercially or are important nuisance species. Studies of the reproductive tissues with electron microscopic and physiological techniques will establish the basis of the mechanical forces that expel eggs and sperm from adults and how these are blocked by high water motion. Field studies of natural communities in New England estuaries will complement the laboratory work. These studies will advance understanding of the mechanisms by which marine algae respond to environmental variables that affect reproductive success. This information should be useful to basic scientists, marine engineers, coastal zone managers, and mariculturists.