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Sex-specific Shift in Age and Morphological Traits of a Non-native Toad Introduced to Beijing About 100 Years Ago
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作者 Tianyi QI Yuchen WANG +5 位作者 Jiajie YU Yonghong XI Jun DING Zhuo YAN Yunyi LU Xuan LIU 《Asian Herpetological Research》 2025年第2期125-133,共9页
Successful non-native species can exhibit rapid divergence of key phenotypic traits to facilitate population persistence and further range expansion.Such phenotypic shifts can be sex-dependent as males and females usu... Successful non-native species can exhibit rapid divergence of key phenotypic traits to facilitate population persistence and further range expansion.Such phenotypic shifts can be sex-dependent as males and females usually have distinct reproductive and dispersal modes responding to relevant selective forces.Here,we showed significant phenotypic divergence in a set of fitness-related traits among males but not among females in the introduced oriental fire-bellied toads(Bombina orientalis),which established a non-native population in Beijing after being introduced in 1927.Specifically,compared with the native counterparts,introduced males displayed younger age and reduced body size,but increased hindlimb length and eye size after controlling the age effect.As the toads have male-biased sex ratio and male-biased dispersal during breeding season,the observed shifts may suggest that the male-biased selective forces have induced increased energy allocation to dispersal and foraging,and thus decreased allocation to maintain longevity in males.Overall,our study provides evidence for the modification of fitness-related phenotypic traits in a non-native anuran population compared with native populations and extends our understanding of key trait divergence in established non-native amphibian under sexual-unbalanced selective forces. 展开更多
关键词 AMPHIBIAN life history morphology non-native species operational sex ratio phenotypic divergence sexbiased dispersal
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Theoretical and Experimental Study on Ground Coupled Heat Pump with Vertical Spiral Coil 被引量:4
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作者 李新国 周倩 +2 位作者 赵军 朱强 胡璟 《Transactions of Tianjin University》 EI CAS 2003年第2期123-126,共4页
The numeric al simulation study on the temperature distribution of underground field for the ground coupled heat pump (GCHP) with vertical spira l coil was carried out by using finite element. The distribution and rec... The numeric al simulation study on the temperature distribution of underground field for the ground coupled heat pump (GCHP) with vertical spira l coil was carried out by using finite element. The distribution and recovery of undergroun d field temperature under different operation ratio and the optimal operation ratio were simulated.The performance parameters, i.e. inlet and outlet temperature of the ground spiral coil in heating and cooling modes were tested, the heat extracted or emitted by the heat pump to the ground was calculated, and the coefficients of performance (COP) of GCHP at heat ing and cooling modes were analyzed. 展开更多
关键词 ground coupled heat pump (GCHP) vert ic al spiral coil underground temperature distribution optimal operation ratio
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Sex roles and sexual selection: lessons from a dynamic model system 被引量:2
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作者 Trond AMUNDSEN 《Current Zoology》 SCIE CAS CSCD 2018年第3期363-392,共30页
Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexuall... Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexually selected traits in females. At the same time, the focus has shifted from documenting sexual selection to exploring variation and spatiotemporal dynamics of sexual selection, and their evolutionary consequences. Here, I review insights from a model system with exceptionally dynamic sexual selection, the two-spotted goby fish Gobiusculus flavescens. The species displays a complete reversal of sex roles over a 3-month breeding season. The reversal is driven by a dramatic change in the operational sex ratio, which is heavily male-biased at the start of the season and heavily female-biased late in the season. Early in the season, breeding-ready males outnumber mature females, causing males to be highly competitive, and leading to sexual selection on males. Late in the season, mating-ready females are in excess, engage more in courtship and aggression than males, and rarely reject mating opportunities. With typically many females simultaneously courting available males late in the season, males become selective and prefer more colorful females. This variable sexual selection regime likely explains why both male and female G. flavescens have ornamental colors. The G. flavescens model system reveals that sexual behavior and sexual selection can be astonishingly dynamic in response to short-term fluctuations in mating competition. Future work should explore whether sexual selection is equally dynamic on a spatial scale, and related spatiotemporal dynamics. 展开更多
关键词 adult sex ratio female ornament Gobiusculus flavescens male ornament mate choice mate search mating compe-tition operational sex ratio OSR two-spotted goby
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Nephila spider male aggregation:preference for optimal female size and web clustering
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作者 Matjaž KUNTNER Maj KUNTNER +4 位作者 Eva KUNTNER Irena KUNTNER Jana FAGANELI PUCER Erik ŠTRUMBELJ Daiqin LI 《Integrative Zoology》 2025年第4期793-799,共7页
Sexual size dimorphism theory predicts biased operational sex ratios(OSRs)and an uneven distribution of males among certain females.We studied this phenomenon through a field census of the giant wood spider Nephila pi... Sexual size dimorphism theory predicts biased operational sex ratios(OSRs)and an uneven distribution of males among certain females.We studied this phenomenon through a field census of the giant wood spider Nephila pilipes(family Nephilidae)in Singapore,a species where females are,on average,6.9 times larger than males.Specifically,we tested two hypotheses concerning male distribution,given their tendency to aggregate in certain female webs.The optimal female size hypothesis predicts that males would predominantly occupy webs of intermediate-sized females.The web clustering hypothesis posits that more males would be found in webs closer together compared to those farther apart.Our snapshot census revealed a female-biased OSR(females:males=1.85)with an uneven distribution of males in female webs.Most males were found in webs of intermediate-sized females aligning with the optimal female size hypothesis.Proximity among female webs was indicative of male presence,lending support to the web clustering hypothesis.While our study's limited sample size warrants caution,we conclude that in N.pilipes,male occupation of female webs is facilitated by the clustering of webs,and males prefer to cohabit with optimally sized,receptive females. 展开更多
关键词 eSSD Nephila pilipes operational sex ratios sexual selection sexual size dimorphism
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