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The three-dimensional hydrodynamics of tadpole model’s solitary swimming and parallel schooling

Journal of Hydrodynamics 2020年第3期32卷 548-560页

作者： Ting-ting Li Wen-rong Hu Xu-yang Chen Department of Engineering Mechanics Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Jiao Tong University and Chiba University International Cooperative Research Center(SJTU-CUICRC) Shanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Hydrodynamics Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering Tokyo Institute of TechnologyTokyoJapan

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.

关键词： 3-D tadpole parallel schooling numerical simulation

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A numerical study of tadpole swimming in the wake of a D-section cylinder

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Journal of Hydrodynamics 2017年第6期29卷 1044-1053页

作者：袁昊天胡文蓉 Department of Engineering Mechanics Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Jiao Tong University and Chiba University International Cooperative Research Center(SJTU-CU-ICRC) Shanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Hydrodynamics Shanghai Jiao Tong UniversityShanghai 200240China

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.

关键词： tadpole undulating in wake vortex interaction

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A Rapid, Non-invasive Method for Anatomical Observations of tadpole Vertebrae in Vivo

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Asian Herpetological Research 2018年第2期9卷 99-109页

作者： Guocheng SHU Shan XIONG Wenyan ZHANG Jianping JIANG Cheng LI Feng XIE Chengdu Institute of Biology Chinese Academy of Sciences Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China

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.

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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Asian Herpetological Research 2021年第1期12卷 100-109页

作者： Jakub PACON Wojciech KRUSZYNSKI Jaroslaw PACON Department of Genetics Wroclaw University of Environmental and Life SciencesKozuchowska 751-631 WroclawWroclaw 51631Poland Department of Internal Medicine and Clinic of Diseases of Horses Dogs and CatsWroclaw University of Enviromnental and Life SciencesPl.Grunwaldzki 4750-366 WroclawWroclaw 50366Poland

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.

关键词： Polypedates megacephalus tadpole mortality the spot-legged tree frog

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Genotoxicity of Three Avermectins on Polypedates megacephalus tadpoles Using the Comet Assay

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Asian Herpetological Research 2016年第4期7卷 251-257页

作者： Baorong GENG Lingling ZHANG Yun JIANG Xiuping HUANG Jinmei DAI College of Life Sciences Fujian Normal University

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.

关键词： Polypedates megacephalus tadpole avermectins abamectin ivermectin emamectin benzoate DNAdamage comet assay

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Time to feed： How diet, competition, and experience may influence feeding behaviour and cannibalism in wood frog tadpoles Lithobates sylvaticus

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Current Zoology 2014年第5期60卷 571-580页

作者： Dale M. JEFFERSON Keith A. HOBSON Douglas P. CHIVERS Department of Biology University of Saskatchewan 112 Science PI. Saskatoon SK Canada S7N 5E2 Environment Canada 11 Innovation Blvd. Saskatoon SK Canada S7N 3H5 Keith.Hobson@ec.gc.ca Department of Biology University of Saskatchewan 112 Science PI. Saskatoon SK Canada S7N 5E2 Doug.Chivers@usask.ca

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 ].

关键词： Cannibal Chemical cues Competition Diet tadpole Wood frog

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Morphology of Kaloula rugifera and K. borealis tadpoles(Anura: Microhylidae: Kaloula verrucosa Group) in China

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Asian Herpetological Research 2011年第3期2卷 169-175页

作者： Bing ZHOU Pipeng LI Yuyan LU Jing LIAN Zhengyan ZHOU Institute of Applied Ecology Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Institute of Herpetology and Liaoning Key Lab of Evolution and Biodiversity Shenyang Normal University

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.

关键词： tadpole external morphology oral disc internal oral feature taxonomy

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A neglected risk for sparganosis:eating live tadpoles in central China

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Infectious Diseases of Poverty 2017年第1期6卷 502-505页

作者： Jing Cui Ye Wang Xi Zhang Xi-Meng Lin Hong-Wei Zhang Zhong-Quan Wang Jia-Xu Chen Department of Parasitology Medical CollegeZhengzhou UniversityZhengzhouChina Department of Emergency Peking University Third HospitalBeijingChina Institute of Parasitic Diseases Center for Disease Prevention and Control of Henan ProvinceZhengzhouChina National Institute of Parasitic Diseases Chinese Center for Disease Control and PreventionKey Laboratory of Parasite and Vector BiologyMinistry of HealthShanghaiChina

A 29-year-old farmer from central China was sent into the Emergency Department of the Affiliated Hospital of Zhengzhou *** had a 15-day history of persistent high fever,abdominal distention and *** patient was clinically diagnosed as appendicitis and peritonitis,and treated with antibiotics in a local hospital,did not *** exploratory laparotomy,the appendicular perforation and peritonitis were seen;appendicectomy were performed,and antibiotics were ***,high fever and abdominal pain still persisted;intestinal adhesion and obstruction,ascites *** 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 *** anti-sparganum antibodies assayed by ELISA were *** patient has hospitalized for one and half months and spend more than US$*** patient was primarily diagnosed as visceral sparganosis,and cured with *** is one neglected but important parasitic zoonosis of *** 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 ***,sparganosis caused by ingestion of live tadpoles are emerging in central *** surveys showed that 11.93%of tadpoles in Henan province are infected with *** live tadpoles is a high risk for sparganum *** comprehensive public health education should be carried out for people in endemic areas and the bad habit of eating live tadpoles must be discouraged.

关键词： Sparganosis Sparganum tadpole Central China

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Effects of hydroperiod duration on developmental plasticity in tiger frog （Hoplobatrachus chinensis） tadpoles

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Zoological Research 2014年第2期35卷 124-131页

作者： Xiao-Li FAN Zhi-Hua LIN Jie WEI College of Ecology Lishui University

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

关键词： Hoplobatrachus chinensis tadpole Water level Metamorphosis Developmental plasticity Jumping ability

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Effects of light intensity on activity in four sympatric anuran tadpoles

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Zoological Research 2014年第4期35卷 332-337页

作者： Guo-Hua DING Zhi-Hua LIN Li-Hua ZHAO Xiao-Li FAN Li WEI College of Ecology Lishui University

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

关键词： Anura Activity Developmental stage Light intensity tadpole

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