The ＂dangerous niche＂ hypothesis posits that neophobia functions to reduce the cost of habitat use among animals exposed to unknown risks. For example, more dangerous foraging or higher competi- tion may lead to inc...The ＂dangerous niche＂ hypothesis posits that neophobia functions to reduce the cost of habitat use among animals exposed to unknown risks. For example, more dangerous foraging or higher competi- tion may lead to increased spatial neophobia. Likewise, elevated ambient predation threats have been shown to induce phenotypically plastic neophobic predator avoidance. In both cases, neophobia is argued to reduce the cost of living associated with ecological uncertainty. Here, we test the hypothesis that ambient predation shapes both neophobic predator avoidance and spatial and foraging neophobia in Trinidadian guppies. Guppies were exposed to a novel foraging arena paired with a known cue （conspecific alarm cue）, a novel cue （lemon odor）, or a stream water control in three streams differing in ambient predation risk. We demonstrate that guppies from a high-predation-risk stream exhibited risk-averse foraging patterns regardless of the chemical stimulus presented （high spatial neophobia） and that those from a low-predation-risk stream were only risk-averse when the foraging arenas were paired with conspecific alarm cue （lower spatial neophobia）. Those tested in the intermediate- predation-risk stream were consistently intermediate to the high-risk vs. low-risk populations. Our study suggests that ambient predation risk shapes both neophobic predator avoidance and space-use pat- terns and that neophobia may function as a ＂generalized＂ response to ecological uncertainty.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
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
文摘The ＂dangerous niche＂ hypothesis posits that neophobia functions to reduce the cost of habitat use among animals exposed to unknown risks. For example, more dangerous foraging or higher competi- tion may lead to increased spatial neophobia. Likewise, elevated ambient predation threats have been shown to induce phenotypically plastic neophobic predator avoidance. In both cases, neophobia is argued to reduce the cost of living associated with ecological uncertainty. Here, we test the hypothesis that ambient predation shapes both neophobic predator avoidance and spatial and foraging neophobia in Trinidadian guppies. Guppies were exposed to a novel foraging arena paired with a known cue （conspecific alarm cue）, a novel cue （lemon odor）, or a stream water control in three streams differing in ambient predation risk. We demonstrate that guppies from a high-predation-risk stream exhibited risk-averse foraging patterns regardless of the chemical stimulus presented （high spatial neophobia） and that those from a low-predation-risk stream were only risk-averse when the foraging arenas were paired with conspecific alarm cue （lower spatial neophobia）. Those tested in the intermediate- predation-risk stream were consistently intermediate to the high-risk vs. low-risk populations. Our study suggests that ambient predation risk shapes both neophobic predator avoidance and space-use pat- terns and that neophobia may function as a ＂generalized＂ response to ecological uncertainty.
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。
