以斑马鱼(Zebra fish)Danio rerio、剑尾鱼Xiphophorus hellerii、孔雀鱼(Guppy)Poecilia reticulata为受试鱼种,采用半静态试验,考察苯、苯酚、氯苯、4-氯苯酚对3种鱼的急性毒性,结果表明,上述4种有机物对斑马鱼的96 h LC50分别为132.2...以斑马鱼(Zebra fish)Danio rerio、剑尾鱼Xiphophorus hellerii、孔雀鱼(Guppy)Poecilia reticulata为受试鱼种,采用半静态试验,考察苯、苯酚、氯苯、4-氯苯酚对3种鱼的急性毒性,结果表明,上述4种有机物对斑马鱼的96 h LC50分别为132.22、28.86、9.66、4.29 mg.L-1;对剑尾鱼的96 h LC50分别为123.76、27.25、8.86、4.29 mg.L-1;对孔雀鱼的96 h LC50分别为131.25、27.88、9.33、4.59 mg.L-1,都属于高毒物质。毒性大小为苯<苯酚<氯苯<4-氯苯酚。毒性大小与取代基的类型有关,-Cl的毒性要大于-OH,-Cl和-OH的联合毒性大于单独的-Cl和-OH。孔雀鱼和剑尾鱼对上述有机污染物具有较好的敏感性,结果稳定,重现性好,可以作为急性毒性试验的受试鱼种。展开更多
主要研究了2,6-二硝基甲苯(2,6-DNT)和4-硝基甲苯(4-NT)两种硝基芳烃对虹鳉鱼的急性毒性、亚急性毒性及联合毒性效应,旨在为渔业水质标准的制定与完善提供可靠的科学依据。研究表明,2,6-DNT的急性毒性大于4-NT,二者的96 h LC50值分别为(...主要研究了2,6-二硝基甲苯(2,6-DNT)和4-硝基甲苯(4-NT)两种硝基芳烃对虹鳉鱼的急性毒性、亚急性毒性及联合毒性效应,旨在为渔业水质标准的制定与完善提供可靠的科学依据。研究表明,2,6-DNT的急性毒性大于4-NT,二者的96 h LC50值分别为(25.22±0.19)mg/L和(60.26±0.09)mg/L;亚急性毒性研究中,两种化合物的各种质量浓度在40天内,对试验动物的生长有不同程度的影响;应用Marking相加指数法评价二者的联合毒性,结果表明其联合毒性为协同。展开更多
Holographic quantitative structure activity relationship(HQSAR) is an emerging QSAR technique with the combined application of molecular hologram, which encoded the frequency of occurrence of various molecular fragme...Holographic quantitative structure activity relationship(HQSAR) is an emerging QSAR technique with the combined application of molecular hologram, which encoded the frequency of occurrence of various molecular fragment types, and the subsequent partial least squares(PLS) regression analysis. In this paper, the acute toxicity data to the guppy( poecilia reticulata) for a series of 56 substituted benzenes, phenols, aromatic amines and nitro aromatics were subjected and this resulted in a model with a high predictive ability. The influence of fragment size and fragment distinction parameters on the quality of HQSAR model was investigated. The robustness and predictive ability of the model were also validated by leave one out (LOO) cross validation procedure and external testing data set.展开更多
A preliminary study was conducted to investigate the effects of the extracts of 112 medicinal plant species, collected from the southern part of Thailand, on Aedes aegypti. Studies on larvicidal properties of plant ex...A preliminary study was conducted to investigate the effects of the extracts of 112 medicinal plant species, collected from the southern part of Thailand, on Aedes aegypti. Studies on larvicidal properties of plant extracts against the fourth instar larvae revealed that extracts of 14 species showed evidence of larvicidal activity. Eight out of the 14 plant species showed 100% mosquito larvae mortality. The LC50 values were less than 100μg/mL （4.1μg/ mL-89.4μg/mL）. Six plant species were comparatively more effective against the fourth instar larvae at very low concentrations. These extracts demonstrated no or very low toxicity to guppy fish （Poecilia reticulata）, which was selected to represent most common non-target organism found in habitats ofAe. aegypti, at concentrations active to mosquito larvae. Three medicinal plants with promising larvicidal activity, having LC50 and LC50 values being 4.1 and 16.4 μg/mL for Mammea siamensis, 20.2 and 34.7 μg/mL forAnethum graveolens and 67.4 and 110.3μg/mL forAnnona muricata, respectively, were used to study the impact of the extracts on the life cycle ofAe. aegypti. These plants affected pupal and adult mortality and also affected the reproductive potential of surviving adults by reducing the number of eggs laid and the percentage of egg hatchability. When each larval stage was treated with successive extracts at the LC50 value, the first instar larvae were found to be very susceptible to A. muricata and the second instar larvae were found to be susceptible to A. graveolens, while the third and fourth instar larvae were found to be susceptible to M. siamensis. These extracts delayed larval development and inhibited adult emergence and had no adverse effects on P. reticulata at LC50 and LC50 values, except for the M. siamensis extract at its LC50 value.展开更多
The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has pro- vided invaluable insight...The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has pro- vided invaluable insights into the process of evolution by natural selection. Although Trinidadian guppies are now a textbook example of evolution in action, studies have generally categorized predation as a dichotomous variable, representing high or low risk. Yet, ecologists appreciate that community structure and the attendant predation risk vary substantially over space and time. Here, we use data from a longitudinal study of fish assemblages at 16 different sites in the Northern Range to quantify temporal and spatial variation in predation risk. Specifically we ask： 1） Is there evidence for a gradient in predation risk？ 2） Does the ranking of sites （by risk） change with the defi- nition of the predator community （in terms of species composition and abundance currency）, and 3） Are site rankings consistent over time？ We find compelling evidence that sites lie along a contin- uum of risk. However, site rankings along this gradient depend on how predation is quantified in terms of the species considered to be predators and the abundance currency is used. Nonetheless, for a given categorization and currency, rankings are relatively consistent over time. Our study sug- gests that consideration of predation gradients will lead to a more nuanced understanding of the role of predation risk in behavioral and evolutionary ecology. It also emphasizes the need to justify and report the definition of predation risk being used.展开更多
Forty embryonic hearts were taken out by anatomical needle from denuded embryos of the ovovivipar-ity guppy fish that were dechorioned by mechanic method or by trypsin digestion, and were in vitro cultured. In the cul...Forty embryonic hearts were taken out by anatomical needle from denuded embryos of the ovovivipar-ity guppy fish that were dechorioned by mechanic method or by trypsin digestion, and were in vitro cultured. In the cultured hearts, 80% have maintained beating in vitro for 4 weeks, and the longest record for beating was 142 d. Owing to fish embryo transparency, beating frequency and blood color changes are easily viewed from the embryonic hearts under a dissecting microscope. The current study established the in vitro culture method of embryonic hearts in guppy fish, which can be used as a model for the study of heart and cardiovascular system in vertebrates.展开更多
Although the majority of studies on mate choice focus on female mate choice, there is growing recognition of the role of male mate choice too. Male mate choice is tightly linked to 2 other phenomena： female competiti...Although the majority of studies on mate choice focus on female mate choice, there is growing recognition of the role of male mate choice too. Male mate choice is tightly linked to 2 other phenomena： female competition for males and ornamentation in females. In the current article, I review the existing literature on this in a group of fishes, Poeciliidae. In this group, male mate choice appears to be based on differences in female quality, especially female size, which is a proxy for fecundity. Some males also have to choose between heterospecific and conspecific females in the unusual mating system of the Amazon molly. In this case, they typically show a preference for conspecific females. Whereas male mate choice is relatively well documented for this family, female ornamentation and female competition are not.展开更多
Animal behavior is remarkably variable at all taxonomic levels. Over the last decades, research on animal behavior has focused on understanding ultimate processes. Yet, it has progressively become more evident that to...Animal behavior is remarkably variable at all taxonomic levels. Over the last decades, research on animal behavior has focused on understanding ultimate processes. Yet, it has progressively become more evident that to fully understand beha- vioral variation, ultimate explanations need to be complemented with proximate ones. In particular, the mechanisms generating variation in sexual behavior remain an open question. Variation in aspects of brain morphology has been suggested as a plausible mechanism underlying this variation. However, our knowledge of this potential association is based almost exclusively on com- parative analyses. Experimental studies are needed to establish causality and bridge the gap between micro- and macroevolutio- nary mechanisms concerning the link between brain and sexual behavior. We used male guppies that had been artificially selected for large or small relative brain size to study this association. We paired males with females and scored the full known set of male and female sexual behaviors described in guppies. We found several previously demonstrated associations between male traits, male behavior and female behavior. Females responded more strongly towards males that courted more and males with more orange coloration. Also, larger males and males with less conspicuous coloration attempted more coerced copulations. However, courting, frequency of coerced copulation attempts, total intensity of sexual behavior, and female response did not differ between large- and small-brained males. Our data suggest that relative brain size is an unlikely mechanism underlying variation in sexual behavior of the male guppy. We discuss these findings in the context of the conditions under which relative brain size might affect male sexual behavior .展开更多
Predation is a pervasive selection pressure,shaping morphological,physiological,and behavioral phenotypes of prey species.Recent studies have begun to examine how the effects of individual experience with predation ri...Predation is a pervasive selection pressure,shaping morphological,physiological,and behavioral phenotypes of prey species.Recent studies have begun to examine how the effects of individual experience with predation risk shapes the use of publicly available risk assessment cues.Here,we investigated the effects of prior predation risk experience on disturbance cue production and use by Trinidadian guppies Poecilia reticulata under laboratory conditions.In our first experiment,we demonstrate that the response of guppies from a high predation population(Lopinot River)was dependent upon the source of disturbance cue senders(high vs.low predation populations).However,guppies collected from a low predation site(Upper Aripo River)exhibited similar responses to disturbance cues,regardless of the sender population.In our second experiment,we used laboratory strain guppies exposed to high versus low background risk conditions.Our results show an analogous response patterns as shown for our first experiment.Guppies exposed to high background risk conditions exhibited stronger responses to the disturbance cues collected from senders exposed to high(vs.low)risk conditions and guppies exposed to low risk conditions were not influenced by sender experience.Combined,our results suggest that experience with background predation risk significantly impacts both the production of and response to disturbance cues in guppies.展开更多
文摘以斑马鱼(Zebra fish)Danio rerio、剑尾鱼Xiphophorus hellerii、孔雀鱼(Guppy)Poecilia reticulata为受试鱼种,采用半静态试验,考察苯、苯酚、氯苯、4-氯苯酚对3种鱼的急性毒性,结果表明,上述4种有机物对斑马鱼的96 h LC50分别为132.22、28.86、9.66、4.29 mg.L-1;对剑尾鱼的96 h LC50分别为123.76、27.25、8.86、4.29 mg.L-1;对孔雀鱼的96 h LC50分别为131.25、27.88、9.33、4.59 mg.L-1,都属于高毒物质。毒性大小为苯<苯酚<氯苯<4-氯苯酚。毒性大小与取代基的类型有关,-Cl的毒性要大于-OH,-Cl和-OH的联合毒性大于单独的-Cl和-OH。孔雀鱼和剑尾鱼对上述有机污染物具有较好的敏感性,结果稳定,重现性好,可以作为急性毒性试验的受试鱼种。
文摘主要研究了2,6-二硝基甲苯(2,6-DNT)和4-硝基甲苯(4-NT)两种硝基芳烃对虹鳉鱼的急性毒性、亚急性毒性及联合毒性效应,旨在为渔业水质标准的制定与完善提供可靠的科学依据。研究表明,2,6-DNT的急性毒性大于4-NT,二者的96 h LC50值分别为(25.22±0.19)mg/L和(60.26±0.09)mg/L;亚急性毒性研究中,两种化合物的各种质量浓度在40天内,对试验动物的生长有不同程度的影响;应用Marking相加指数法评价二者的联合毒性,结果表明其联合毒性为协同。
文摘Holographic quantitative structure activity relationship(HQSAR) is an emerging QSAR technique with the combined application of molecular hologram, which encoded the frequency of occurrence of various molecular fragment types, and the subsequent partial least squares(PLS) regression analysis. In this paper, the acute toxicity data to the guppy( poecilia reticulata) for a series of 56 substituted benzenes, phenols, aromatic amines and nitro aromatics were subjected and this resulted in a model with a high predictive ability. The influence of fragment size and fragment distinction parameters on the quality of HQSAR model was investigated. The robustness and predictive ability of the model were also validated by leave one out (LOO) cross validation procedure and external testing data set.
文摘A preliminary study was conducted to investigate the effects of the extracts of 112 medicinal plant species, collected from the southern part of Thailand, on Aedes aegypti. Studies on larvicidal properties of plant extracts against the fourth instar larvae revealed that extracts of 14 species showed evidence of larvicidal activity. Eight out of the 14 plant species showed 100% mosquito larvae mortality. The LC50 values were less than 100μg/mL （4.1μg/ mL-89.4μg/mL）. Six plant species were comparatively more effective against the fourth instar larvae at very low concentrations. These extracts demonstrated no or very low toxicity to guppy fish （Poecilia reticulata）, which was selected to represent most common non-target organism found in habitats ofAe. aegypti, at concentrations active to mosquito larvae. Three medicinal plants with promising larvicidal activity, having LC50 and LC50 values being 4.1 and 16.4 μg/mL for Mammea siamensis, 20.2 and 34.7 μg/mL forAnethum graveolens and 67.4 and 110.3μg/mL forAnnona muricata, respectively, were used to study the impact of the extracts on the life cycle ofAe. aegypti. These plants affected pupal and adult mortality and also affected the reproductive potential of surviving adults by reducing the number of eggs laid and the percentage of egg hatchability. When each larval stage was treated with successive extracts at the LC50 value, the first instar larvae were found to be very susceptible to A. muricata and the second instar larvae were found to be susceptible to A. graveolens, while the third and fourth instar larvae were found to be susceptible to M. siamensis. These extracts delayed larval development and inhibited adult emergence and had no adverse effects on P. reticulata at LC50 and LC50 values, except for the M. siamensis extract at its LC50 value.
文摘The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has pro- vided invaluable insights into the process of evolution by natural selection. Although Trinidadian guppies are now a textbook example of evolution in action, studies have generally categorized predation as a dichotomous variable, representing high or low risk. Yet, ecologists appreciate that community structure and the attendant predation risk vary substantially over space and time. Here, we use data from a longitudinal study of fish assemblages at 16 different sites in the Northern Range to quantify temporal and spatial variation in predation risk. Specifically we ask： 1） Is there evidence for a gradient in predation risk？ 2） Does the ranking of sites （by risk） change with the defi- nition of the predator community （in terms of species composition and abundance currency）, and 3） Are site rankings consistent over time？ We find compelling evidence that sites lie along a contin- uum of risk. However, site rankings along this gradient depend on how predation is quantified in terms of the species considered to be predators and the abundance currency is used. Nonetheless, for a given categorization and currency, rankings are relatively consistent over time. Our study sug- gests that consideration of predation gradients will lead to a more nuanced understanding of the role of predation risk in behavioral and evolutionary ecology. It also emphasizes the need to justify and report the definition of predation risk being used.
基金This work was supported by the Major State Basic Research Program (Grant No. G1999053908) of China and the Special Life Science and Biotechnology Foundation of the Chinese Academy of Sciences.
文摘Forty embryonic hearts were taken out by anatomical needle from denuded embryos of the ovovivipar-ity guppy fish that were dechorioned by mechanic method or by trypsin digestion, and were in vitro cultured. In the cultured hearts, 80% have maintained beating in vitro for 4 weeks, and the longest record for beating was 142 d. Owing to fish embryo transparency, beating frequency and blood color changes are easily viewed from the embryonic hearts under a dissecting microscope. The current study established the in vitro culture method of embryonic hearts in guppy fish, which can be used as a model for the study of heart and cardiovascular system in vertebrates.
文摘Although the majority of studies on mate choice focus on female mate choice, there is growing recognition of the role of male mate choice too. Male mate choice is tightly linked to 2 other phenomena： female competition for males and ornamentation in females. In the current article, I review the existing literature on this in a group of fishes, Poeciliidae. In this group, male mate choice appears to be based on differences in female quality, especially female size, which is a proxy for fecundity. Some males also have to choose between heterospecific and conspecific females in the unusual mating system of the Amazon molly. In this case, they typically show a preference for conspecific females. Whereas male mate choice is relatively well documented for this family, female ornamentation and female competition are not.
文摘Animal behavior is remarkably variable at all taxonomic levels. Over the last decades, research on animal behavior has focused on understanding ultimate processes. Yet, it has progressively become more evident that to fully understand beha- vioral variation, ultimate explanations need to be complemented with proximate ones. In particular, the mechanisms generating variation in sexual behavior remain an open question. Variation in aspects of brain morphology has been suggested as a plausible mechanism underlying this variation. However, our knowledge of this potential association is based almost exclusively on com- parative analyses. Experimental studies are needed to establish causality and bridge the gap between micro- and macroevolutio- nary mechanisms concerning the link between brain and sexual behavior. We used male guppies that had been artificially selected for large or small relative brain size to study this association. We paired males with females and scored the full known set of male and female sexual behaviors described in guppies. We found several previously demonstrated associations between male traits, male behavior and female behavior. Females responded more strongly towards males that courted more and males with more orange coloration. Also, larger males and males with less conspicuous coloration attempted more coerced copulations. However, courting, frequency of coerced copulation attempts, total intensity of sexual behavior, and female response did not differ between large- and small-brained males. Our data suggest that relative brain size is an unlikely mechanism underlying variation in sexual behavior of the male guppy. We discuss these findings in the context of the conditions under which relative brain size might affect male sexual behavior .
基金Concordia University and the Natural Science and Engineering Research Council of Canada to G.E.B.
文摘Predation is a pervasive selection pressure,shaping morphological,physiological,and behavioral phenotypes of prey species.Recent studies have begun to examine how the effects of individual experience with predation risk shapes the use of publicly available risk assessment cues.Here,we investigated the effects of prior predation risk experience on disturbance cue production and use by Trinidadian guppies Poecilia reticulata under laboratory conditions.In our first experiment,we demonstrate that the response of guppies from a high predation population(Lopinot River)was dependent upon the source of disturbance cue senders(high vs.low predation populations).However,guppies collected from a low predation site(Upper Aripo River)exhibited similar responses to disturbance cues,regardless of the sender population.In our second experiment,we used laboratory strain guppies exposed to high versus low background risk conditions.Our results show an analogous response patterns as shown for our first experiment.Guppies exposed to high background risk conditions exhibited stronger responses to the disturbance cues collected from senders exposed to high(vs.low)risk conditions and guppies exposed to low risk conditions were not influenced by sender experience.Combined,our results suggest that experience with background predation risk significantly impacts both the production of and response to disturbance cues in guppies.
