Life cycle of the trematode worm, Exorchis mupingensis, includes Oncomelania hupensis snail as first intermediate host and several small freshwater fishes as second intermediate hosts, while the carnivorous fish, Para...Life cycle of the trematode worm, Exorchis mupingensis, includes Oncomelania hupensis snail as first intermediate host and several small freshwater fishes as second intermediate hosts, while the carnivorous fish, Parasilurus asotus, serves as a final host of this parasite. P. asotus fish, Labidochromis caeruleus fish and E. mupingensis cercariae were used in the laboratory to determine the time that mature metacercariae of E. mupingensis take to develop into an adult worm within the final host. Results showed that the period of development of the mature metacercariae of E. mupingensis into an adult worm within the final host, P. asotus, is ca. 30 d.展开更多
The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preferenc...The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preference of this species. In the field, the body temperatures of the turtles conformed to the water temperature, with little diel variation in either summer or au- tumn. Over the diel cycle, the mean body temperatures ranged from 20.8℃ to 22.2℃ in summer and from 19.3℃ to 21.2℃ in autumn; the highest body temperatures ranged from 22.1℃ to 25.0℃ in summer and from 20.6℃ to 23.8℃ in autumn. In the laboratory, the preferred body temperature （Tp） was 25.3℃ Food intake was maximized at 24.0℃, whereas locomotor perfor- mance peaked at 30.0℃. Consequently, Tp was closer to the thermal optimum for food intake than for locomotion. Therefore, this freshwater turtle has relative low field body temperatures corresponding to its thermal environment. In addition, the turtle prefers low temperatures and has a low optimal temperature for food intake [Current Zoology 59 （5）： 626-632, 20＇13].展开更多
基金Acknowledgments The authors thank the staff of Animal Diseases Institute, Hanshou, Hunan province, China, for their assistance during the field work. This research was funded by the National Natural Science Foundation of China （No. 31270938）.
文摘Life cycle of the trematode worm, Exorchis mupingensis, includes Oncomelania hupensis snail as first intermediate host and several small freshwater fishes as second intermediate hosts, while the carnivorous fish, Parasilurus asotus, serves as a final host of this parasite. P. asotus fish, Labidochromis caeruleus fish and E. mupingensis cercariae were used in the laboratory to determine the time that mature metacercariae of E. mupingensis take to develop into an adult worm within the final host. Results showed that the period of development of the mature metacercariae of E. mupingensis into an adult worm within the final host, P. asotus, is ca. 30 d.
文摘The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preference of this species. In the field, the body temperatures of the turtles conformed to the water temperature, with little diel variation in either summer or au- tumn. Over the diel cycle, the mean body temperatures ranged from 20.8℃ to 22.2℃ in summer and from 19.3℃ to 21.2℃ in autumn; the highest body temperatures ranged from 22.1℃ to 25.0℃ in summer and from 20.6℃ to 23.8℃ in autumn. In the laboratory, the preferred body temperature （Tp） was 25.3℃ Food intake was maximized at 24.0℃, whereas locomotor perfor- mance peaked at 30.0℃. Consequently, Tp was closer to the thermal optimum for food intake than for locomotion. Therefore, this freshwater turtle has relative low field body temperatures corresponding to its thermal environment. In addition, the turtle prefers low temperatures and has a low optimal temperature for food intake [Current Zoology 59 （5）： 626-632, 20＇13].
