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Testing An Ecophysiological Mechanism Of Morphological Plasticity In Pupfish And Its Relevance To Conservation Efforts For Endangered Devils Hole Pupfish, Sean C. Lema, Gabrielle A. Nevitt Sep 2006

Testing An Ecophysiological Mechanism Of Morphological Plasticity In Pupfish And Its Relevance To Conservation Efforts For Endangered Devils Hole Pupfish, Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

Imperiled species that have been translocated or established in captivity can show rapid alterations in morphology and behavior, but the proximate mechanisms of such phenotypic changes are rarely known. Devils Hole pupfish (Cyprinodon diabolis) are endemic to a single desert pool and are characterized by a small body, large head and eyes, and lack of pelvic fins. To lessen the risk of extinction, additional populations of C. diabolis were established in artificial refuges. Yet, pupfish in these refuges rapidly shifted to a larger body, smaller head and eyes, and greater body depth. Here we examined how food availability …


Population Divergence In Plasticity Of The Avt System And Its Association With Aggressive Behaviors In A Death Valley Pupfish, Sean C. Lema Aug 2006

Population Divergence In Plasticity Of The Avt System And Its Association With Aggressive Behaviors In A Death Valley Pupfish, Sean C. Lema

Biological Sciences

Behavioral differences can evolve rapidly in allopatry, but little is known about the neural bases of such changes. Allopatric populations of Amargosa pupfish (Cyprinodon nevadensis) vary in aggression and courtship behaviors in the wild. Two of these wild populations were recently found to differ in brain expression of arginine vasotocin (AVT)—a peptide hormone shown previously to modulate aggression in pupfish. These populations have been isolated for less than 4000 years, so it remained unclear whether the differences in behavior and neural AVT phenotype were evolved changes or plastic responses to ecologically dissimilar habitats. Here, I tested whether these …


The Biology Of Canadian Weeds. 133. Cuscuta Campestris Yuncker, C. Gronovii Willd. Ex Schult., C. Umbrosa Beyr. Ex Hook., C. Epithymum (L.) L. And C. Epilinum Weihe, Mihai Costea, François J. Tardif Jan 2006

The Biology Of Canadian Weeds. 133. Cuscuta Campestris Yuncker, C. Gronovii Willd. Ex Schult., C. Umbrosa Beyr. Ex Hook., C. Epithymum (L.) L. And C. Epilinum Weihe, Mihai Costea, François J. Tardif

Biology Faculty Publications

Cuscuta spp. (dodders) are rootless, holoparasitic herbs with filiform stems attached to the host by numerous haustoria. In Canada, Cuscuta gronovii is the most common native species of the genus followed by Cuscuta campestris and C. umbrosa. Cuscuta epithymum and C. epilinum, both introduced species in Canada, occur occasionally. Infestation by Cuscuta spp. can result in serious yield losses and dodders are listed as noxious weeds in British Columbia, Ontario and Québec, and as restricted weeds in Alberta. These plants have evolved special adaptations to ensure their success: germination occurs late in the season when potential hosts are …


Sexual Dimorphic Social Development And Female Intrasexual Chemical Signaling Of African Elephants (Loxodonta Africana), Jordana M. Meyer Jan 2006

Sexual Dimorphic Social Development And Female Intrasexual Chemical Signaling Of African Elephants (Loxodonta Africana), Jordana M. Meyer

Electronic Theses and Dissertations

Author's abstract: African elephants are a polygynous species in which males and females carry out dimorphic lifestyles. Males search and compete for reproductively active females, while females care for offspring and facilitate group cohesion. The objectives of this study was a) to compare the development of sexually dimorphic behaviors and developmental trends between young male and female wild African elephants and b) to determine the ability of captive female African elephants to discern between the follicular and luteal phase of conspecifics through trunk-tip contacts and the investigation of urine, and whether the reproductive phase of the receiver affected the response …