国外一篇关于野采考察的文章(有美图)

2006 Saturdaze Scholarship for Natural History Research: Sayward Halling
Scholarship Award: $2,000









点击链接可以看到简单翻译的中文
http://translate.google.com.hk/t ... t%2F2006scholar.htm
Institution: College of Creative Studies, UCSB
Major: Biology, Emphasis in Parasitology
Advisor: Dr. Armand Kuris
Future Profession: Science Journalist

Academic Goals: Although my plans are malleable and invariably in some state of flux, I do have a general idea of where I will be going after I graduate from UCSB. I intend to do my graduate work at Oregon Health and Science University, most likely working on bacterial pathogens. I am as of yet undecided whether I will be completing a Masters or PhD. I love to write and entertain grand fantasies of being a science journalist. So, I may earn my Masters at OHSU and then move on to a Masters program in Science Journalism, ideally at Columbia University in New York. If I do not take that route, I will certainly finish my PhD at OSHU.

That is my current plan, but in all honesty it may very well change. All I really know is that I will be continuing my education, and I have a lot of options as to how to go about doing that. And that's enough for me.  

Professional Goals: To me, science journalism is the ideal profession. Writing about science would allow me to forever be learning, which is what I truly love. It would allow me to explore all aspects of biology and the sciences, and to examine the most cutting edge research and technology. It would allow me to flex my creative muscle and express myself artistically, which is something that is also very important to my heart. And finally, it would give me a chance to offer science to the non-scientific community in a fun and informative way, and possibly spark interest in a population whose scientific knowledge seems to be in a serious state of decline.

Of course I would be honored to write for such prestigious journals as Science or Nature, but I imagine I would be equally happy writing for children. I grew up reading Ranger Rick magazine and I think it would be wonderful to be a part of that publication - bringing the magic of the natural world to the next generation of scientists. I could also imagine having a science column in a Newspaper or weekly such as the Independent, or even writing books along the lines of Carl Zimmer's "Parasite Rex" or Brian Green's "The Elegant Universe."

Research Interest: I currently study parasitology, and there isn't enough room for me to list why it interests me. Suffice to say, I am absolutely fascinated by the unique role that parasites play in the natural world. From their amazing co-evolution with their hosts, to their extreme evolutionary adaptation and modification, to the many and various roles they play in their ecosystems, I adore parasites because they are some of the most highly adapted, most abundant, and most understudied organisms on the planet.

I currently work in a lab that focuses on the role of digenean trematodes in salt marsh habitats. My lab is the first to quantify total parasite biomass in an ecosystem, a staggering figure that will no doubt alter the way ecologists approach ecosystem dynamics in the future. As well, we study all aspects of the more than 20 species of digenes within our system, which will lend insight into the habits, behaviors, and life histories of these organisms. This may be useful to the scientific and health communities, as digenes are notorious scourges to both humans and livestock throughout the world.

Abstract of Research: Fish Predation on Trematode Cercariae in a California Estuary

In salt marsh ecosystems where the snail Cerithidea californica is infected with digenean trematodes, billions of cercariae are shed into the estuary every day. But, a large percentage of cercariae do not reach their second intermediate hosts. Cercarial mortality factors are little studied and the role of predators as a mortality source is unknown. Our laboratory studies indicate that several zooplanktivorous fishes are potential predators. Seven local estuarine fish species were brought into the lab and offered cercariae from twelve trematode species that reside with them in the marsh. Thirty minutes after the fish were presented with cercariae, they were examined for the presence of cercariae in the gut.

The juvenile fishes that preyed on cercariae in the lab are currently being investigated in the field. Juvenile fishes exhibiting eating behavior will be collected from the shallows as cercariae are being shed (as triggered by a warm sun and a rising tide). They will then be immediately dissected to examine their gut contents for the presence of cercariae. We expect that certain cercarial species are more prone to being eaten by fishes, indicating a differential preference on the part of the fish. The abundance of juvenile fishes in the marsh suggests that they may be a quantitatively significant source of mortality of these transmission stages.  

Carpinteria Salt Marsh Reserve

The depth of the meandering tributaries of the channel through the Carpinteria Salt Marsh Reserve rise and fall with the tides. At high tide the channels flood with seawater; at low tide they drain to expose a rich organic mud. During winter storms they flood with freshwater, but still rise and fall with the tides. The salinity of the water changes on an annual as well as daily basis. Plants and animals that live within these waters must withstand a wide range of salinities and exposure to air. Despite these challenges, the organisms adapted to these conditions thrive and the density of living organisms is high.



Within the salt marshes spotted along coastal California, the California Horn Snail occupies an intermediate position in the hierarchy of salt marsh ecosystems. Using a large vacuum-like proboscis, these snails feed on microalgae (cyanobacteria and diatoms on the surface of mud) and, in turn, are fed upon by salt marsh crabs. Horn Snails also are intermediate in position in the life history of a variety of parasitic trematode worms whose hosts are snails, fish and birds.

The adult trematode worms live in the digestive tracts and organs of birds from which the eggs are released with the bird's feces. The eggs hatch in the water to become searching miracidium larvae which burrow into the snail. Within the snail development continues through a complex series of asexual multiplications.

The result of these asexual stages in the life history of the worm is that from one egg hundreds of cercariae larvae are produced. Cercariae burrow out of the snail in search of a fish. Penetrating a fish, a cercaria becomes a metacercaria and, depending on where it lodges, changes the behavior of the fish, making the fish more noticeable to a bird predator . . . and more likely to be eaten, completing the life history of the worm.





The final hosts of the trematode worms are birds that rely on the fish as food. Trematode larvae that enter the muscles and nervous system of the fish cause abnormal swimming behavior. When one watches the tributaries of the marsh, one can see see a shimmer in the water as the parasitized fish flash their sides upwards as they swim erratically. These fish most certainly attract the attention of avian predators.



Nineteen different trematode species have been identified so far and all have the Horn Snail as an intermediate host. An analysis of the complex food and parasite webs within the marsh has revealed nearly 1000 links within the food chains and parasite transfer between hosts. These links would all be lost with the disappearnce of the Horn Snail. In addition, the "chain of hosts" from snail to one of several fish to one of many birds, is specific for each trematode. Eliminating any one of the links in this chain would eliminate the parasite.



Ms Halling's research is directed at a "turnabout" link in the parasite chain. The fishes that as adults would be hosts to the parasites, as juveniles they are predators on the infectious stages, the cercariae.



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说实话，翻译不咋地

2K美刀........好啊

穿比基尼野采{:4_117:}{:4_117:}

既来之，则安之。何不练习下英文？

azpop 发表于 2011-11-2 16:05

                               
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回复 滨海原生 的帖子

讲中国话你听得见么？本来是外国人的帖子，要看中文的可以点击链接，google机器翻译 ...

听不见，但写中国字我看的懂，这是中国。感谢LZ教的翻译方法。

回复 滨海原生 的帖子

讲中国话你听得见么？本来是外国人的帖子，要看中文的可以点击链接，google机器翻译的，可以看个大略的意思。

麻烦楼主在中国，讲中国话。谢谢~~

穿比基尼野采...么

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