Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication
- Publication Type
Articles 1 - 4 of 4
Full-Text Articles in Life Sciences
Parasite Infection Mediates Trait Tradeoffs In Fundulus Heteroclitus, Sarah Dunn
Parasite Infection Mediates Trait Tradeoffs In Fundulus Heteroclitus, Sarah Dunn
Honors College Theses
To be successful, an animal must eat, grow, and reproduce. With limited resources, there are tradeoffs between these critical life history parameters but the direction of the tradeoffs is largely unknown in a changing environment. To determine whether environmental context affects life-history tradeoffs, I surveyed and quantified investment into reproduction, growth, and a proxy for immunity (parasitism), in the mummichog, Fundulus heteroclitus, a common inhabitant of salt marshes in Georgia. Three salt marsh sites along coastal Georgia (Shellman Bluff, Skidaway Island, and Tybee Island) were selected using a proxy for anthropogenic disturbance (impervious surface), which also fell along a …
The Reproductive Ecology Of The Timber Rattlesnake, Crotalus Horridus, In Northwestern Arkansas: Interactions Between Environment, Steroid Hormones, And Life History, Craig Michael Lind
The Reproductive Ecology Of The Timber Rattlesnake, Crotalus Horridus, In Northwestern Arkansas: Interactions Between Environment, Steroid Hormones, And Life History, Craig Michael Lind
Graduate Theses and Dissertations
In this dissertation I examined the relationship between individual energetic status, hormone production, and life history trait expression in field-active Timber Rattlesnakes, Crotalus horridus. In chapter one I reviewed what is known regarding these relationships in snakes and defined major research goals. In chapter two I described the seasonal profile of testosterone (T) and corticosterone (CORT) in relation to the breeding season and to individual energetic status in males. Results showed that the seasonal pattern of T production in C. horridus was different than other pit viper species with similar mating patterns. Testosterone was elevated in the months leading up …
Evolution, Systematics & Geographic Parthenogenesis Of Ilyodromus (Crustacea, Ostracoda), Rylan James Shearn
Evolution, Systematics & Geographic Parthenogenesis Of Ilyodromus (Crustacea, Ostracoda), Rylan James Shearn
Theses
Most multicellular organisms reproduce sexually at some point in their life cycle. This is paradoxical because being asexual is theoretically far more advantageous. Asexual organisms do not need to find and court new mates, they reproduce at a faster rate, and with no males, all members of the population contribute toward population growth rate. With over 20, often mutually exclusive hypotheses, this paradox resists a synthesised explanation, and continues to represent one of the largest gaps in our understanding of fundamental evolutionary theory. Clearly, more real world studies are required that document the selective mechanisms underlying differences in evolutionary fitness …
Reproductive Biology Of Syntopic Blackside Dace And Southern Redbelly Dace In Two Kentucky Streams, Brajaan Hayes
Reproductive Biology Of Syntopic Blackside Dace And Southern Redbelly Dace In Two Kentucky Streams, Brajaan Hayes
Online Theses and Dissertations
When a rare endemic species and an ecologically similar, but more cosmopolitan species share habitat, understanding how they interact with each other is important for conservation efforts. This is especially true if both species rely on the same spawning habitat, which could potentially lead to competitive displacement or hybridization. It is known that the federally threatened Blackside Dace and common Southern Redbelly Dace are ecologically similar species, occur syntopically in Kentucky in the upper Cumberland River basin, and utilize some of the same host species for nest sites; however, it is unclear if the two fish species are spawning site …