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Effects of hydroperiod duration on developmental plasticity in tiger frog (Hoplobatrachus chinensis) tadpoles 被引量:3
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作者 Xiao-Li FAN Zhi-Hua LIN Jie WEI 《Zoological Research》 CAS CSCD 北大核心 2014年第2期124-131,共8页
While developmental plasticity can facilitate evolutionary diversification of organisms, the effects of water levels as an environmental pressure on tiger frogs remains unclear. This study clarifies the relationship b... While developmental plasticity can facilitate evolutionary diversification of organisms, the effects of water levels as an environmental pressure on tiger frogs remains unclear. This study clarifies the relationship by studying the responses of tiger frog (Hoplobatrachus chinensis) tadpoles to simulated hydroperiods (i.e., constant low water levels, constant high water levels, increasing water levels, decreasing water levels, rapid changes in water levels and gradual fluctuations in water levels) in a laboratory setting. ANOVA analysis showed that none of the water level treatments had any significant effect on the total length, body mass, or developmental stages of H. chinensis tadpoles half way through development (11 days old). Tadpoles raised in rapidly fluctuating water levels had protracted metamorphosis, whereas tadpoles raised under low and gradually fluctuating water levels had shortened metamorphosis. None of the water level treatments had a significant effect on the snout-vent length (SVL) or body mass of H. chinensis tadpoles at Gosner stage 42, or on the body mass of tadpoles at Gosner stage 45. However, the' tadpoles raised in high levels and rapidly fluctuating water levels, significantly larger SVL at Gosner stage 45, while ones under gradually fluctuating water levels had smaller SVL than the other groups. Time to metamorphosis was positively correlated with body size (SVL) at metamorphosis in H. chinensis tadpoles. H. chinensis tadpoles under constant low water level had the highest mortality rate among all the treatments (G-test). Moreover, ANOVA and ACNOVA (with body length as the covariate) indicated that water levels had no significant effect on either the morphology (i.e. head length, head width, forelimb length, hindlimb length and body width) or the jumping ability of juvenile H. chinensis. These results suggest that the observed accelerated metamorphosis and high mortality of H. chinensis tadpoles under decreasing water level treatment was driven by density-induced physical interaetions among increasing conspeeifics. 展开更多
关键词 Hoplobatrachus chinensis tadpole Water level METAMORPHOSIS Developmental plasticity Jumping ability
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Effects of Predation by Invasive Western Mosquitofish(Gambusia affinis) on Survival of Eggs,Embryos and Tadpoles of Pelophylax nigromaculatus and Duttaphrynus melanostictus in South China 被引量:3
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作者 Xiaoli FAN Zhihua LIN +2 位作者 Xiang LI Li WEI Guohua DING 《Asian Herpetological Research》 SCIE CSCD 2016年第1期46-52,共7页
Alien species are one of the most serious threats to the decline and extinction of native amphibian populations. In this study, we examined the predation of invasive Western Mosquitofish Gambusia affinis on the eggs, ... Alien species are one of the most serious threats to the decline and extinction of native amphibian populations. In this study, we examined the predation of invasive Western Mosquitofish Gambusia affinis on the eggs, embryos, and tadpoles of Duttaphrynus melanostictus and Pelophylax nigromaculatus in south China. Our results suggested that the survival of eggs and embryos remaining in the egg capsules of P. nigromaculatus and D. melanostictus was significantly higher than those removed from the egg capsule at 12-h intervals within 72 h in the presence of G. affinis. The survival of P. nigromaculatus eggs and embryos without egg capsules was significantly lower than those of D. melanostictus without egg capsules. The survival of P. nigromaculatus eggs and embryos with egg capsules was significantly higher than those of D. melanostictus with egg capsules from 24 h to 72 h except for 12 h. The survival of D. melanostictus tadpoles was significantly higher than that of P. nigromaculatus tadpoles in the presence of G. affinis. The survival of Gosner stage 26 tadpoles of P. nigromaculatus was significantly higher than that of Gosner stage 30 tadpoles from 12 h to 60 h, but there were no significant differences at 72 h. In contrast, the survival of Gosner stage 26 tadpoles of D. melanostictus was significantly lower than that of Gosner stage 30 tadpoles within 72 h, recording every 12 h. The increasing temperature caused a significant increase in predation by G. affinis on P. nigromaculatus eggs and embryos. The outer jelly capsule surrounding anurans eggs might serve as a mechanical defense against predation by G. affinis due to its large diameter, relatively stationary state and unpalatability. The differences in the vulnerability of P. nigromaculatus and D. melanostictus embryos and tadpoles to G. affinis probably due to differences in the unpalatability, black skin and activity. Based on the magnitude of predation by G. affinis on the eggs, embryos and tadpoles of these two species and the combined impact of temperature, we might speculate that invasive G. affinis and global warming would have more detrimental impacts on population viability of P. nigromaculatus than D. melanostictus in China. 展开更多
关键词 amphibian anura tadpoleS EGGS embryos predation risk
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Genotoxicity of Three Avermectins on Polypedates megacephalus Tadpoles Using the Comet Assay 被引量:1
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作者 Baorong GENG Lingling ZHANG +2 位作者 Yun JIANG Xiuping HUANG Jinmei DAI 《Asian Herpetological Research》 SCIE CSCD 2016年第4期251-257,共7页
Avermectins are a new class of macrocyclic lactones derived from mycelia of the soil actinomycete, and are used as effective agricultural pesticides and antiparasitic agents. However, run-off from crops treated with a... Avermectins are a new class of macrocyclic lactones derived from mycelia of the soil actinomycete, and are used as effective agricultural pesticides and antiparasitic agents. However, run-off from crops treated with avermectins may contaminate various bodies of water, and accumulated to certain concentrations to impact the development of aquatic animals. Here, we tested the genotoxicity of three avermectins (abamectin, ABM; ivermectin, IVM; and emamectin benzoate, EMB) on Polypedates megacephalus tadpoles by the alkaline single-cell gel electrophoresis assay. Tadpoles were treated for 48 h in the laboratory with different concentrations of these three agents, 0.006, 0.012, 0.018, 0.024, 0.030 mg/L for ABM, 0.003, 0.006, 0.009, 0.012, 0.015 mg/L for IVM and 0.04, 0.06, 0.08, 0.10, 0.12 mg/L for EMB, and then measured their DNA damage by the Comet assay tail factor %. The concentrations of resulted in highly significant increases in DNA damage of the tadpoles were found above the concentration threshold of 0.012 mg/ L ABM, 0.003 mg/L IVM and 0.06 mg/L EMB and linear correlations between the intensity of DNA damage and the concentrations of these three avermectins. Our results showed clearly that avermectins caused dose dependent DNA damage on amphibian tadpoles, and there might be a control on the misuse of avermectins. 展开更多
关键词 Polypedates megacephalus tadpole AVERMECTINS ABAMECTIN IVERMECTIN emamectin benzoate DNAdamage comet assay
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Effects of light intensity on activity in four sympatric anuran tadpoles 被引量:1
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作者 Guo-Hua DING Zhi-Hua LIN +2 位作者 Li-Hua ZHAO Xiao-Li FAN Li WEI 《Zoological Research》 CAS CSCD 北大核心 2014年第4期332-337,共6页
Though light conditions are known to affect the development and anti-predation strategies of several aquatic species, relatively little is known about how different species react to light, or how light can affect thes... Though light conditions are known to affect the development and anti-predation strategies of several aquatic species, relatively little is known about how different species react to light, or how light can affect these species during different points in their life-cycle. In this study, we used four sympatric anuran tadpoles (Bufo gargarizans, B. melanostictus, Pelophylax nigromaculatus and Microhyla fissipes) as animal system to examine species-specific activities of the underdoing different light intensity treatments, so as to better understand how they respond to light. We exposed four different species of tadpoles to 1660 and 14 lux light intensity treatments and then measured several parameters including development stage, body length and tail length, and as well as their basic activities. The results of this observation and analysis showed that the activities of tadpoles were significantly greater in B. gargarizans and B. melanostictus than in P. nigromaculatus and M. fissipes; and were also significantly greater during times of high light intensity as compared to during low light intensity. Moreover, the observed relationship between species and light intensity was significant. The activities ofB. gargarizans and B. melanostictus tadpoles were greater in high light, while the activity of P. nigromaculatus tadpoles was greater in low light intensity, while M. fissipes tadpoles showed no differences in either low or high intensity light. Furthermore, the activities orB. gargarizans, B. melanostictus and M. fissipes tadpoles in terms of developmental stage, body size or tail length did not seem to differ with light intensity, but during early larval developmental period of P. nigromaculatus, the activity of tadpoles was negatively correlated with development stage, but irrelevant to either body size or tail length in different light intensities. These results lead us to conclude the observed activities of the four sympatric anuran tadpoles are closely correlated with their specific anti-predation strategies. 展开更多
关键词 ANURA ACTIVITY Developmental stage Light intensity tadpole
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Morphology of Kaloula rugifera and K. borealis Tadpoles(Anura: Microhylidae: Kaloula verrucosa Group) in China 被引量:1
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作者 Bing ZHOU Pipeng LI +2 位作者 Yuyan LU Jing LIAN Zhengyan ZHOU 《Asian Herpetological Research》 SCIE 2011年第3期169-175,共7页
The external morphology and internal oral features of the tadpoles of Kaloula rugifera and K. borealis are described in this paper. Similarities between these two larvae include external morphology, oral disc, interna... The external morphology and internal oral features of the tadpoles of Kaloula rugifera and K. borealis are described in this paper. Similarities between these two larvae include external morphology, oral disc, internal oral features(floor and roof), terminal mouth, lateral eyes, single midventral spiracle, absence of keratinized jaw sheaths and labial teeth, absence of lingual papillae and postnarial arena, while the body of K. rugifera is bigger than that of K. borealis at stages from 36 to 39 and the number of papillae in the buccal cavity is 12–19 and 9–16, respectively in the two species. All the similarities and differences of the two species illustrate that the tadpoles within the family Microhylidae could be attributed to assistance in clarifying a certain taxonomic treatment in Microhylidae. 展开更多
关键词 tadpole external morphology oral disc internal oral feature taxonomy
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Bioconcentration kinetics of PCBs in various parts of the lifecycle of the tadpoles Xenopus laevis
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作者 ZHAO Rong-biao SUN Da-yu +2 位作者 FU Shan WANG Xiao-fei ZHAO Ru-song 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第3期374-384,共11页
Polychlorinated biphenyls (PCBs) in Xenopus laevis have been reported only for a few congeners. Additionally, there is very little information on the ability of Xenopus laevis to bioconcentrate PCBs. To address thes... Polychlorinated biphenyls (PCBs) in Xenopus laevis have been reported only for a few congeners. Additionally, there is very little information on the ability of Xenopus laevis to bioconcentrate PCBs. To address these issues, the tadpole Xenopus laevis was exposed to Aroclor 1254 mixtures in water at room temperature for 110 d followed by an additional 110 d of nonspiked PCBs in the water for the control group. During the whole process, bioconcentration factors (BCFs) of PCBs ranged from 1180 to 15670. For most PCB congeners, the highest and lowest bioconcentrations of the kinetic curves were found to be remarkably simultaneous, respectively. All 141 PCB congeners under the same experimental conditions had no linear correlation on the lgBCF versus lgKow relationship. The relationship between lgBCFs and lgKow followed a parabolic pattern indicative of selective bioconcentration, suggesting that the kinetic curves of the PCB congeners observed in the lifecycle of the tadpoles may be concentrated due to the amphibian special species and internal metabolism. In contrast, lgBCFs for PCBs were inversely related to lgKow, suggesting that a metabolism of the higher Kow PCB congeners occurred. These results support the author's conclusion that the tadpole Xenopus laevis plays major roles in the bioconcentration of PCB congeners, and demonstrated that the exposure kinetic curves of PCB congeners are complex. Besides the amphibian metamorphous development, the lifecycle of the tadpole Xenopus laevis also may be of importance in determining the bioconcentration of PCB congeners. 展开更多
关键词 PCBS tadpole Xenopus laevis BIOCONCENTRATION exposure kinetics
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Differentiations of 5-HT and GAS cells in the digestive canals of Rana chensinensis tadpoles
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作者 Xin-Yi LI Qian LI Yu-Hui ZHANG 《Zoological Research》 CAS CSCD 北大核心 2014年第4期326-331,共6页
In the current study, 5-nydroxytryptamine (5-HT) and gastrin (GAS) cells in the digestive canals of Rana chensinensis tadpoles at different developmental stages were investigated by immunohistochemistry. Results s... In the current study, 5-nydroxytryptamine (5-HT) and gastrin (GAS) cells in the digestive canals of Rana chensinensis tadpoles at different developmental stages were investigated by immunohistochemistry. Results showed that the 5-HT cells were only detected in the duodenum before metamorphosis began, and were extensively distributed in the stomach, duodenum, small intestine, and rectum thereafter, with the highest counts found in the duodenum and rectum when metamorphosis was completed. The GAS cells were only distributed in the stomach and duodenum, and only rarely detected in the duodenum before metamorphosis began, but increased in the stomach during metamorphosis and showed zonal distribution in the gastric mucosa when metamorphosis was completed. Metamorphosis is a critical period for amphibians, during which structural and functional physiological adaptations are required to transition from aquatic to terrestrial environments. During metamorphosis, the differentiations of 5-HT cells in the gastrointestinal canals of tadpoles could facilitate mucus secretion regulation, improve digestive canal lubrication, and help water- shortage food digestion in terrestrial environments. Conversely, GAS cell differentiations during metamorphosis might contribute to the digestive and absorptive function transition from herbivore to omnivore. 展开更多
关键词 Rana chensinensis tadpole Digestive canal 5-nydroxytryptamine (5-HT) cell Gastrin (GAS) cell Ontogeny
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A Rapid, Non-invasive Method for Anatomical Observations of Tadpole Vertebrae in Vivo
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作者 Guocheng SHU Shan XIONG +3 位作者 Wenyan ZHANG Jianping JIANG Cheng LI Feng XIE 《Asian Herpetological Research》 SCIE CSCD 2018年第2期99-109,共11页
The tadpole is a critical stage in the amphibian life cycle and plays an important role during the transition from the aquatic to the terrestrial stage. However, there is a large gap in tadpole research, which represe... The tadpole is a critical stage in the amphibian life cycle and plays an important role during the transition from the aquatic to the terrestrial stage. However, there is a large gap in tadpole research, which represents a vital component of our understanding of the diversity and complexity of the life history traits of amphibians, especially their developmental biology. Some aspects of this gap are due to limited research approaches. To date, X-ray microcomputed tomography (micro-CT) has been widely used to conduct osteology research in adult amphibians and reptiles, but little is known about whether this tool can be applied in tadpole studies. Thus, we compared the results of two methods (the bone-cartilage double-staining technique and micro-CT) to study vertebrae in tadpole specimens. The results revealed no significant difference between the two methods in determining the number of vertebrae, and micro-CT represents a rapid, non-invasive, reliable method of studying tadpole vertebrae. When scanning tadpoles, voltage is the most critical of the scanning parameters (voltage, current and scan time), and moderate scanning parameters are recommended. In addition, micro-CT performed better using specimens stored in 70% ethanol than those preserved in 10% formalin. Finally, we suggest that micro-CT should be more widely applied in herpetological research to increase specimen utilization. 展开更多
关键词 MICRO-CT bone-cartilage double-stain tadpole VERTEBRAE
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The Influence of Environmental Factors on the Behavior and Mortality Risk of Polypedates megacephalus Tadpoles
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作者 Jakub PACON Wojciech KRUSZYNSKI Jaroslaw PACON 《Asian Herpetological Research》 SCIE CSCD 2021年第1期100-109,共10页
Since tadpoles change their behavior when facing adverse environmental conditions, observing tadpoles in a tank can help detect problems in their ma intena nce. Detecting such a bnormal behavior early, an amphibian br... Since tadpoles change their behavior when facing adverse environmental conditions, observing tadpoles in a tank can help detect problems in their ma intena nce. Detecting such a bnormal behavior early, an amphibian breeder can react quickly, by changing the conditions. If quick and appropriate, such a reaction can save unnecessary deaths. The paper presents an experimental study on the behavior of tadpoles of Polypedates megacephalus in various adverse environmental conditions. In addition to a control 25-liter tank, 5-liter tanks with 10 tadpoles each were studied, each having various improper conditions. Observations included the degree of tank exploration by the tadpoles, their mortality, anomalies in swimming behavior, and eating behavior. 展开更多
关键词 Polypedates megacephalus tadpole MORTALITY the spot-legged tree frog
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Changes on Anuran Tadpole Functional Diversity along an Environmental Gradient at the Southernmost Atlantic Rainforest Remnant
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作者 Victor Mendes LIPINSKI Andre Passaglia SCHUCH Tiago Gomes dos SANTOS 《Asian Herpetological Research》 SCIE CSCD 2020年第1期63-70,共8页
For decades the ecologists are using the same methods in order to determine the environmental health of a community,however,the crescent need on defining how these processes act,triggered the development of new method... For decades the ecologists are using the same methods in order to determine the environmental health of a community,however,the crescent need on defining how these processes act,triggered the development of new methods that could classify the organisms and their function at the habitats.Here we used the anuran larvae to understand the effects of an environmental gradient on the structure and organization of the anuran assemblages along it,and to access in a realistic form,the actual state of preservation of the la rgest remnant of Atlantic Rainforest on the Southernmost portion of Brazil.We found that despite the higher diversity of species and the conservation unit status of the place,the ecosystem itself is still in danger,given the low number of functional groups and thus a higher number of ecosystem services that can be lost. 展开更多
关键词 ANURAN ECOSYSTEM function conservation unities tadpoleS
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Antipredator Behavioral Responses of Native and Exotic Tadpoles to Novel Predator
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作者 Fang ZHANG Juan ZHAO +2 位作者 Yujie ZHANG Kevin MESSENGER Yong WANG 《Asian Herpetological Research》 SCIE CSCD 2015年第1期51-58,共8页
Factors related to the invasion process, such as high abundance of invaders, residence time, and functional distinctiveness, are well documented, but less attention has been given to the effects of antipredator strate... Factors related to the invasion process, such as high abundance of invaders, residence time, and functional distinctiveness, are well documented, but less attention has been given to the effects of antipredator strategy of invasive species during colonization. In this study, we explored the antipredator strategy of an introduced species by comparing the predator avoidance behaviors of two native anuran species and one introduced (“exotic”) species in the presence of different predators. The two native anuran species used in the study were Black-spotted Pond FrogRana nigromaculata and Terrestrial Frog Rana limnocharis. The introduced (invasive) species used was American bullfrogLithobates catesbeianus. Chinese pond turtleChinemys reevesii, Red-backed rat snakeElaphe rufodorsata, and Big-headed turtle Platysternon megacephalum were used as predator species. Chinese pond turtles and Red-backed rat snakes are native predators of Black-spotted Pond Frogs and Terrestrial Frogs, while Big-headed turtles are novel (“unfamiliar”) to the two frogs. All three predator species are novel (“unfamiliar”) to the American bullfrog. The results show that tadpoles of the two native species displayed behaviors of recognizing the two native predators, but did not display the capability of identifying the novel predator. Results from our study also suggest that American bullfrog tadpoles exhibited strong antipredator behavioral responses by displaying the capability of identifying “unfamiliar” predators without cohabitation history and prior exposure to them. Such antipredator behavioral responses could have resulted in more favorable outcomes for an invading species during the invasive introductory process. 展开更多
关键词 tadpoleS BULLFROG antipredator responses chemical cues novel predator
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enriched diets and the growth, development and survival of litoria moorei (anura) tadpoles reared in captivity at low density
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《Asian Herpetological Research》 SCIE 2010年第2期-,共8页
Increasing numbers of amphibian species require conservation breeding programs for their survival.A major challenge is the efficient rearing of tadpoles,many of which require complex habitats and specialised diets.Aqu... Increasing numbers of amphibian species require conservation breeding programs for their survival.A major challenge is the efficient rearing of tadpoles,many of which require complex habitats and specialised diets.Aquatic tadpoles of the West Australian frog Litoria moorei were kept at low density(1 tadpole per 1.95 litres water) in aquaria at 25℃.Fed on a staple diet of boiled lettuce and leaf litter,group of diets were supplemented with either control,Wardley Premium Spirulina Discs,Sera~(TM) GVG-mix tropical fish food,or a combination of Wardley Premium Spirulina discs and Sera~(TM) GVG-mix fish food.There was a relatively high loss(i.e.,found dead,euthanized due to scoliosis,or not found) of tadpoles fed with the lettuce/leaf litter alone,but this was increased significantly when supplemented with Wardley Premium Spirulina discs,either alone or with Sera~(TM) GVG-mix fish food,and Sera~(TM) GVG fish food alone.However,the survived tadpoles fed on the three supplements were all heavier after three weeks and at metamorphosis than those fed with lettuce/leaf litter alone,and reached metamorphosis quicker.It is concluded that any benefit of the food supplements in terms of increasing the rate of growth and development of the tadpoles is outweighed by greater mortality.There is now a need for the efficient rearing of tadpoles,many from novel species that need complex habitats.Further studies of diet are required due to the current conservation crisis of amphibians. 展开更多
关键词 Litoria moorei commercial food protein tadpole
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Odor cues rather than personality affect tadpole deposition in a neotropical poison frog 被引量:1
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作者 Melissa Peignier Max Ringler Eva Ringler 《Current Zoology》 SCIE CAS CSCD 2024年第3期332-342,共11页
Animals constantly need to evaluate available external and internal information to make appropriate decisions.Identifying,assessing,and acting on relevant cues in contexts such as mate choice,intra-sexual competition,... Animals constantly need to evaluate available external and internal information to make appropriate decisions.Identifying,assessing,and acting on relevant cues in contexts such as mate choice,intra-sexual competition,and parental care is particularly important for optimizing individual reproductive success.Several factors can infuence decision-making,such as external environmental cues and the animal’s own internal state,yet,we have limited knowledge on how animals integrate available information.Here,we used an entire island population(57 males,53 females,and 1,109 tadpoles)of the neotropical brilliant-thighed poison frog Allobates femoralis to investigate how 2 factors(olfactory cues and personality traits)infuence the ability of males to fnd and use new resources for tadpole deposition.We experimentally manipulated the location of tadpole deposition sites and their associated olfactory cues,and repeatedly measured exploration and boldness in adult males.We further reconstructed tadpole deposition choices via inferred parent–offspring relationships of adult frogs and tadpoles deposited in our experimental pools using molecular parentage analysis.We found that the discovery and use of new rearing sites were heavily infuenced by olfactory cues;however,we did not fnd an effect of the measured behavioral traits on resource discovery and use.We conclude that in highly dynamic environments such as tropical rainforests,reliable external cues likely take priority over personality traits,helping individuals to discover and make use of reproductive resources. 展开更多
关键词 animal personality ANURA decision-making parental care tadpole transport
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Tadpole types of Chinese megophryid frogs (Anura: Mego- phryidae) and implications for larval evolution
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作者 Cheng LI Xian-Guang GUO Yue-Zhao WANG 《Current Zoology》 SCIE CAS CSCD 北大核心 2011年第1期93-100,共8页
The larval body shapes and oral discs of 30 frog species from the family Megophryidae from China were examined. Using a phylogenetic framework derived from a Bayesian analysis of published mitochondrial cytochrome b a... The larval body shapes and oral discs of 30 frog species from the family Megophryidae from China were examined. Using a phylogenetic framework derived from a Bayesian analysis of published mitochondrial cytochrome b and 16S rRNA gene sequences, we deduced a pattern of historical change among megophryid larval forms. These larvae were categorized into four types according to their body shapes and oral discs: (A) Leptobrachiini type, (B) Lalax type, (C) Brachytarsophrys type, and (D) Megophryini type, of which B and C are novel types. Type A is characterized by a typical oral disc with multiple rows of teeth, representing the tadpole type of the most recent common ancestor of the family Megophryidae. Type B has a typical oral disc with reduced tooth rows, an elongated labium, and integumentary glands. Type C has no labial teeth and a smaller umbelliform oral disc. Type D is characterized by a lack of labial teeth, an enlarged umbelliform oral disc, representing the tadpole of the most recent common ancestor of the subfamily Megophryinae. Our analysis supports the hypothesis that the umbelliform oral disc is apomorphic and also reveals the close association between morphology and microhabitat 展开更多
关键词 MEGOPHRYIDAE tadpoleS Lalax type Brachytarsophrys type Novel tadpole types
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A neglected risk for sparganosis:eating live tadpoles in central China 被引量:7
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作者 Jing Cui Ye Wang +4 位作者 Xi Zhang Xi-Meng Lin Hong-Wei Zhang Zhong-Quan Wang Jia-Xu Chen 《Infectious Diseases of Poverty》 SCIE 2017年第1期502-505,共4页
A 29-year-old farmer from central China was sent into the Emergency Department of the Affiliated Hospital of Zhengzhou University.He had a 15-day history of persistent high fever,abdominal distention and pain.The pati... A 29-year-old farmer from central China was sent into the Emergency Department of the Affiliated Hospital of Zhengzhou University.He had a 15-day history of persistent high fever,abdominal distention and pain.The patient was clinically diagnosed as appendicitis and peritonitis,and treated with antibiotics in a local hospital,did not improve.On exploratory laparotomy,the appendicular perforation and peritonitis were seen;appendicectomy were performed,and antibiotics were given.However,high fever and abdominal pain still persisted;intestinal adhesion and obstruction,ascites appeared.He was given the“critically ill notice”.He had eosinophilia(12.95%)and the history of eating live frog tadpoles for treating his cutaneous pruritus 3 days before onset of the disease.Serum anti-sparganum antibodies assayed by ELISA were positive.This patient has hospitalized for one and half months and spend more than US$12000.This patient was primarily diagnosed as visceral sparganosis,and cured with praziquantel.Sparganosis is one neglected but important parasitic zoonosis of poverty.Human infections were mainly acquired by eating raw or uncooked meat of frogs and snakes infected with plerocercoids,using frog or snake flesh as poultices,or drinking raw water contaminated with infected copepods.However,sparganosis caused by ingestion of live tadpoles are emerging in central China.Our surveys showed that 11.93%of tadpoles in Henan province are infected with plerocercoids.Eating live tadpoles is a high risk for sparganum infection.The comprehensive public health education should be carried out for people in endemic areas and the bad habit of eating live tadpoles must be discouraged. 展开更多
关键词 SPARGANOSIS Sparganum tadpole Central China
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A Miniaturized Tadpole Robot Using an Electromagnetic Oscillatory Actuator 被引量:5
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作者 Bu Hyun Shin Kyung-Min Lee Seung-Yop Lee 《Journal of Bionic Engineering》 SCIE EI CSCD 2015年第1期29-36,共8页
In this paper, we propose a miniaturized tadpole-like robot using an electromagnetic oscillatory actuator. The electro- magnetic actuator has a simple structure with a moving-magnet type and the body size is 13 mm (l... In this paper, we propose a miniaturized tadpole-like robot using an electromagnetic oscillatory actuator. The electro- magnetic actuator has a simple structure with a moving-magnet type and the body size is 13 mm (length) × 11 mm (height) ×10 mm (width). A tail has the thickness of 100 μm and the length of 20 mm which is twice of the body-length (BL). The tail attached to the oscillatory actuator generates undulatory propulsion for the forward swimming. Moreover, the tadpole robot enables the change of the direction by controlling input signal pattems applied to the oscillatory actuator. Prototypes of the tadpole robot have been manufactured and the thrust force and swimming speed are measured to evaluate the performance of the biomimetic robot in water at various tail-beat frequencies. The maximum thrust force is 42 mN at the tail-beat frequency of 30 Hz with voltage of 3 V, enabling the tadpole robot to swim at the speed of 210 mm·s^-1 (6 BL·s^-1). The tadpole robot can also change its moving direction with the angular velocity of 21 deg·s^-1 at the half pulse pattem of 30 Hz. 展开更多
关键词 fish robot biomimetics tadpole robot electromagnetic actuator
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A numerical study of tadpole swimming in the wake of a D-section cylinder 被引量:6
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作者 袁昊天 胡文蓉 《Journal of Hydrodynamics》 SCIE EI CSCD 2017年第6期1044-1053,共10页
The vortex structure and the hydrodynamic performance of a tadpole undulating in the wake of a D-section cylinder are studied by solving the Navier-Stokes equations for the unsteady incompressible viscous flow. A dyna... The vortex structure and the hydrodynamic performance of a tadpole undulating in the wake of a D-section cylinder are studied by solving the Navier-Stokes equations for the unsteady incompressible viscous flow. A dynamic mesh fitting the tadpole's deforming body surface is used in the simulation. It is found that three main factors can contribute to the thrust of the tadpole behind a D-cylinder: the backward jet in the wake, the local reverse flows on the tadpole surface and the suction force caused by the passing vortices. The tadpole?s relative undulating frequency and the distance between the D-cylinder and the tadpole have a great influence on both the vortex structure and the hydrodynamic performance. At some undulating frequency, a tadpole may break or dodge vortices from the D-cylinder. When the vortices are broken, the tadpole can gain a great thrust but will consume much energy to maintain its undulation. When the vortices are dodged, the tadpole is subject to a small thrust or even a drag. However, it is an effective way to save much energy in the undulating swimming, as the Kármán gait does. As the tadpole is located behind the D-cylinder at different distances, three typical kinds of wake are observed. When an incomplete Kármán vortex street forms between the D-cylinder and the tadpole, the tadpole is subject to the highest thrust. 展开更多
关键词 tadpole undulating in wake vortex interaction
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The three-dimensional hydrodynamics of tadpole model’s solitary swimming and parallel schooling 被引量:2
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作者 Ting-ting Li Wen-rong Hu Xu-yang Chen 《Journal of Hydrodynamics》 SCIE EI CSCD 2020年第3期548-560,共13页
Tadpole swimming, including a solitary tadpole swimming and schooling side-by-side in an in-phase mode, is investigated numerically in the present paper. The three-dimensional Navier-Stokes equations for the unsteady ... Tadpole swimming, including a solitary tadpole swimming and schooling side-by-side in an in-phase mode, is investigated numerically in the present paper. The three-dimensional Navier-Stokes equations for the unsteady incompressible viscous flow are solved. A dynamic mesh fitting the tadpole’s deforming body surface is adopted. The results showed that for a solitary tadpole swimming, two vortex rings are shed in each undulating period. However, as the resultant force on the tadpole is drag, the vortex rings are obviously asymmetric, shaped like “C”. When the resultant force in the swimming direction approaches zero, the axes of the vortex rings are nearly vertical to the swimming direction. Distorted vortex rings are found when the resultant force on the tadpole is thrust. When the tadpole model obtains the optimum propulsive efficiency, its swimming speed and undulating frequency are close to the values observed in nature. For tadpoles swimming side-by-side in an in-phase mode, the vortex structures in the wake may merge, split and recombine. Compared with a solitary tadpole swimming, only a small hydrodynamic advantage occur with schooling in parallel, which may be one of the reasons why tadpoles rarely, if ever swim, side by side for any amount of time or distance in nature. The effect of the undulating frequency on the tadpoles schooling is similar to that on a solitary tadpole. In addition, with an increase in the Reynolds number, the thrust force and the propulsive efficiency both increase, while the power consumption decreases. We also found that the tadpole benefits from the vortex pair shedding from its blunt snout, which can strengthen the vortex intensity in the wake and improve the pressure distribution. 展开更多
关键词 3-D tadpole parallel schooling numerical simulation
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Time to feed: How diet, competition, and experience may influence feeding behaviour and cannibalism in wood frog tadpoles Lithobates sylvaticus 被引量:1
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作者 Dale M. JEFFERSON Keith A. HOBSON Douglas P. CHIVERS 《Current Zoology》 SCIE CAS CSCD 2014年第5期571-580,共10页
Wood frog Lithobates sylvaticus tadpoles develop in temporary wetlands where high population densities can force tadpoles into aggregations that intensify competition and can lead to cannibalism. However, chemical ala... Wood frog Lithobates sylvaticus tadpoles develop in temporary wetlands where high population densities can force tadpoles into aggregations that intensify competition and can lead to cannibalism. However, chemical alarm cues released from injured conspecifics could also dissuade cannibalism. The purpose of this study was to test mechanisms that may influence can- nibalistic behaviour. We tested whether the tendency of tadpoles to consume conspecifics would increase with the presence of competition and/or cues of profitable diets. Tadpoles placed in 1L experimental containers were tested for feeding initiation times of multiple diets, including conspecific tissues and conspecific tissues combined with chemical cues from the alternative diets (brine shrimp and comrneal). Tadpoles were tested in the presence and absence of a competitor, and at multiple times over the course of the study. Tadpoles exhibited an altered response to diets over time; however the presence of a competitor reduced re- sponse times to all diets including conspecific tissues. Similarly, the presence of specific diets also reduced the response time of tadpoles to conspecific tissues. These results suggest competition among feeding tadpoles could result in aggressive behaviour leading to indiscriminate predation and cannibalism [Current Zoology 60 (5): 571-580, 2014 ]. 展开更多
关键词 Cannibal Chemical cues COMPETITION DIET tadpole Wood frog
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Lack of functional link in the tadpole morphology induced by predators
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作者 Maria Gabriela PEROTTI Mariana PUETA +2 位作者 Fabian Gaston JARA Carmen Adria UBED Debora Lina MORENO AZOCAR 《Current Zoology》 SCIE CAS CSCD 2016年第3期227-235,共9页
Most studies of predator-induced plasticity have focused on documenting how prey species re- spond to predators by modifying phenotypic traits and how traits correlate with fitness. We have previously shown that Pleur... Most studies of predator-induced plasticity have focused on documenting how prey species re- spond to predators by modifying phenotypic traits and how traits correlate with fitness. We have previously shown that Pleurodema thaul tadpoles exposed to the dragonfly Rhionaeschna varie- gata responded strongly by showing morphological changes, less activity, and better survival than non-exposed tadpoles. Here, we tested whether there is a functional link between morphological plasticity and increased survival in the presence of predators. Tadpoles that experienced predation risk were smaller, less developed, and much less active than tadpoles without this experience. Burst speed did not correlate significantly with morphological changes and predator-induced deeper tails did not act as a lure to divert predator strikes away from the head. Although we have previously found that tadpoles with predator-induced morphology survive better under a direct predator threat, our results on the functional link between morphology and fitness are not conclu- sive. Our results suggest that in P. thaultadpoles (1) burst speed is not important to evade preda- tors, (2) those exposed to predators reduce their activity, and (3) morphological changes do not divert predator attacks away from areas that compromise tadpole survivalEE. Our results show that morphological changes in P. thaul tadpoles do not explain burst speed or lure attraction, al- though there was a clear reduction of activity, which itself reduces predation. We propose that changes in tadpole activity could be further analyzed from another perspective, with morphological change as an indirect product of behavior mediated by physiological mechanisms. 展开更多
关键词 induced morphology lure effect predator exposure swimming performance tadpoles.
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