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Evaluation of shrimp polyculture system in Thailand based on stable carbon and nitrogen isotope ratios 总被引:1,自引:0,他引:1
HISASHI YOKOYAMA JUNYA HIGANO a KUMIKO ADACHI YUKA ISHIHI YOSHIHIRO YAMADA b 《Fisheries Science》2002,68(4):745-750
ABSTRACT: To quantify the contribution by cocultured animals to waste assimilation in an intensive shrimp farm in Thailand, the food web structures of the macrobenthos in a reservoir pond, a shrimp culture pond and water treatment ponds were examined using the stable C and N isotope ratio technique. Seawater for aquaculture was drawn from a creek, and stored in a reservoir pond, used for farming the banana prawn Fenneropenaeus merguiensis in culture ponds, and then recycled through treatment ponds where the green mussel Perna viridis was cultured to remove organic wastes discharged from the farming. The clam worm Nereididae sp. and the mud creeper Cerithideopsilla cingulata in the culture pond had δ 13 C values of −21.0‰ and −18.4‰, respectively, suggesting that shrimp feed (mean δ 13 C = −20.7‰) was the main food source for these species. The δ 13 C analysis also suggested that sediments (−23.7‰) in the reservoir pond and particulate organic matter (POM) (−24.0‰) and/or sediments (−25.0‰) in the treatment pond supplied carbon for most macrobenthic animals. However, green mussels in the treatment pond had a mean δ 13 C value of −20.5‰, suggesting that shrimp feed was the main food source for this species. 相似文献
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ABSTRACT: A rapid clustering scheme for Vibrio specieswas developed based on the analysis of 16S rDNA, which compriseda group-specific polymerase chain reaction (PCR) and restriction fragmentlength polymorphisms (RFLP) of the PCR-amplified 16S rDNA. The group-specificPCR, using a specific primer Vib1F, clustered the Vibrio speciesinto two large groups: Vib1F+ group and Vib1F– group.The PCR-RFLP, using Sca I and Bln I, further dividedthese groups into smaller groups. Finally, 46 Vibrio speciesand eight related species could be clustered into 14 groups usingthis rapid clustering method. Seasonal dynamics of the Vibrio communityin Yoshimi Bay, Hibiki-nada Sea, Japan, were examined based on therapid clustering method. In both seawater and sediments, the groupcomprised Vibrio parahaemolyticus , Vibrio alginolyticus , Vibriocampbellii , Vibrio carchariae , Vibrio harveyi and Vibrionatriegens and was predominant when the seawater temperaturewas above 20°C, whereas the group of Vibrio splendidus biotypeI and Vibrio lentus was abundant when the temperature wasaround or below 20°C. 相似文献
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The smothering effect of four legume covers, Canavalia ensiformis , Lablab purpureus, Mucuna pruriens and Calopogonium caeruleum , on Pennisetum polystachion ssp. setosum , a troublesome weed in rubber plantations in southern Thailand, was evaluated. Growing legume covers with Pennisetum , M. pruriens , C. ensiformis and L. purpureus caused strong suppression of Pennisetum in this order. Pennisetum grew little under 10% relative light intensity (RLI), but almost normally under 40% RLI. The three legume species generally attained lower RLI than C. caeruleum . The high shading ability of these three species was thought to contribute to the suppression of Pennisetum growth. 相似文献
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