寄生虫和其他传染性媒体会对一个生态系统产生重大影响，其影响的方式是以某种显著的猎物或捕食者为目标。但对加利福尼亚和下加利福尼亚太平洋沿岸三个河口地区自由生活物种及寄生物种的生物量所做的一项研究表明，今后在食物链分析和生态系统模拟研究中，应当对寄生生态给予更多考虑。一个令人吃惊的发现是，寄生虫在这些生态系统中有相当大的生物量，甚至超过顶级捕食者的生物量。例如，与鸟类、鱼类吸虫、掘洞虾和多毛目环节动物的生物量相比，吸虫的生物量尤其高。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 454, 515-518 (24 July 2008) | doi:10.1038/nature06970
Ecosystem energetic implications of parasite and free-living biomass in three estuaries
Armand M. Kuris1,12, Ryan F. Hechinger1,12, Jenny C. Shaw1, Kathleen L. Whitney1, Leopoldina Aguirre-Macedo2, Charlie A. Boch1, Andrew P. Dobson3, Eleca J. Dunham4, Brian L. Fredensborg5, Todd C. Huspeni6, Julio Lorda1, Luzviminda Mababa1, Frank T. Mancini7, Adrienne B. Mora8, Maria Pickering9, Nadia L. Talhouk1, Mark E. Torchin10 & Kevin D. Lafferty11
Department of Ecology, Evolution and Marine Biology and Marine Science Institute, University of California, Santa Barbara, California 93106, USA
Centro de Investigación y Estudios Avanzados del IPN, C.P. 97310, Mérida, Mexico
Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544-1003, USA
Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
Department of Biology, University of Texas Pan-American, Edinburg, Texas 78539, USA
Department of Biology, University of Wisconsin–Stevens Point, Stevens Point, Wisconsin 54481, USA
Pacific Islands Fisheries Research Center, National Marine Fisheries Service, Honolulu, Hawaii 96822, USA
Department of Biology, University of California, Riverside, California 92521, USA
Ecology and Evolutionary Biology, University of Connecticut, Storrs, 75 North Eagleville Rd. Unit 3043, Storrs, Connecticut 06269, USA
Smithsonian Tropical Research Institute, Apartado 0843, Ancon, Balboa 03092, Panama, Republic of Panama
Western Ecological Research Center, US Geological Survey, Marine Science Institute, University of California, Santa Barbara, California 93106, USA
These authors contributed equally to this work.
Correspondence to: Armand M. Kuris1,12 Correspondence and requests for materials should be addressed to A.M.K. (Email: kuris@lifesci.ucsb.edu).
Parasites can have strong impacts but are thought to contribute little biomass to ecosystems1, 2, 3. We quantified the biomass of free-living and parasitic species in three estuaries on the Pacific coast of California and Baja California. Here we show that parasites have substantial biomass in these ecosystems. We found that parasite biomass exceeded that of top predators. The biomass of trematodes was particularly high, being comparable to that of the abundant birds, fishes, burrowing shrimps and polychaetes. Trophically transmitted parasites and parasitic castrators subsumed more biomass than did other parasitic functional groups. The extended phenotype biomass controlled by parasitic castrators sometimes exceeded that of their uninfected hosts. The annual production of free-swimming trematode transmission stages was greater than the combined biomass of all quantified parasites and was also greater than bird biomass. This biomass and productivity of parasites implies a profound role for infectious processes in these estuaries.
