Adakemisk avhandling--Gothenburg. / Extra t.p., with thesis statement, inserted. Bibliography: p. 89-99.

Adakemisk avhandling--Gothenburg. / Extra t.p., with thesis statement, inserted. Bibliography: p. 89-99.

Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 202-213).

Otolith increment morphology of the protandric hermaphrodite Centropomus undecimalis (snook) was analyzed in relation to age and length for sex specific growth differences to retroactively determine the time of sex change. Growth spurts in the otoliths of female snook, the terminal sex, were identified between ages 4 and 8, corroborating the current understanding of when sex change occurs (between 3 and 8). No such growth increases were identified on the otoliths of male snook, the primary sex. Otolith growth, however, was found to decouple from length, so these growth spurts are not reflected in the length of the fish. This study marks the first time that a distinct growth pattern differentiating the primary and terminal sexes, similar to that seen in the protogynous transitional growth spurt hypothesis, has been identified on the otoliths of a protandric species. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

Thesis (M.A.)--Georgia State University, 2006. / 1 electronic text (218 p.) : digital, PDF file. Title from title screen. Mindy Stombler, committee chair; Elisabeth O. Burgess, Wendy Simonds, committee members. Description based on contents viewed Apr. 5, 2007. Includes bibliographical references (p. 207-218).

Dr. Harry Benjamin leant medical legitimacy to transsexualism with the publication of The Transsexual Phenomenon in 1966. Using Benjamin's published works and extensive private correspondence with patients, this thesis examines some aspects of the development of transgender medicine and the relationship between transgendered people and the medical establishment in parts of the twentieth century. It argues that Benjamin's background in European sexology and sex reform, combined with his determination to consider his patients' expressed needs first, put him in the perfect position to develop new treatments for transgendered people. It demonstrates that his patients actively sought medical assistance and concludes that it was ultimately Benjamin's willingness and ability to work outside the bounds of accepted medicine coupled with his patients' drive to live in the gender of their choice that contributed to a significant shift in how the American medical establishment responded to transgendered people in the twentieth century.

Sex-change (or sequential hermaphroditism) is a phenomenon whereby an organism functions first as one sex, and then as the other in the later stage of its life. Sex change is an adaptation that has evolved to allow certain organisms to increase fitness through resource allocation of male and female functions in a single lifespan. Since the timing of sex change in an organism is critical to its reproductive output, the size or age at sex change is expected to be plastic in response to different environmental conditions. Social and environmental conditions usually convey the cues about the relative advantages of functioning as one sex or the other. Identifying the factors that influence the timing at sex change is important to understand the evolution of sex change in the life history. In order to elucidate how to optimize fitness through sex allocation in response to different environment, I studied the timing at sex change of Coralliophila violacea in different approach, including the age of individual, the compositions of social groups and the difference between two types of coral hosts in this thesis. Firstly, I present a method to determine the age of this snail and its age at sex change. The growth striae on the operculum were studied and compared to the age estimated by the Gompertz growth function based on growth data obtained from mark-recapture experiments. There is a significant correlation between the number of striae on the operculum and the age estimated from the Gompertz growth function, and the relationship is 1:1. These results suggest that the number of striae on the operculum can be used as an age index, with each stria representing 1 year of age. The age of sex change of this snail, according to my estimates by both stria number and aperture-length inferences, occurs between 4 and 6 years old. Growth rates of the snails are negatively correlated to size. Furthermore, individuals undergoing sex-change grew faster than males and females. This snail, Coralliophila violacea, forms snail patches on the surface of the massive coral, Porites spp. Secondly, the social factors were analyzed for the timing of this sedentary snail. These factors include the sex ratio, number of male and females, and the size of females in the snail patches, all of which could be important information in determining the timing of sex change. In this study only the size of the largest female could be significantly correlated with the size at sex change in a snail patch. Finally, I survey the distribution, size and reproductive characteristics of the snail, Coralliophila violacea (Lamarck), which inhabits the surface of both the branching coral Porites nigrescens and the massive corals, P. lobata and P. lutea. Based on these results I examined the host effect on (1) population structure and (2) reproductive characteristics, including the size at sex change of symbionts. On branching hosts, most snails were solitary, whereas on massive hosts, most had formed multiple-snail patches. Significantly smaller snails as well as proportionally more females were found on branching than on massive hosts. Furthermore, the fecundity of the females on the branching hosts was significantly lower than that on the massive hosts. The size at sex change (male to female) of the snails was smaller on the branching hosts than on massive hosts. Patch composition differences can partly explain the smaller size at sex change for snails on branching hosts; however, there was also evidence that host morphology had a significant effect on the timing of sex change.

Parasite population dynamics and the evolution of life history characteristics are strongly correlated with the processes of host infection, survival within a host and reproduction, with each process posing a challenge to the parasitic lifestyle. Macroparasites living in marine environments have evolved extreme changes in physiology, morphology and life history traits to overcome these challenges. This study focused on the infective and reproductive stage of the parasitic isopod, Cymothoa excisa, a common parasite on Atlantic croaker, (Micropogonias undulatus), along the Texas coast. A two year survey identified infection rates and the relationship between fish density and size and parasite load, size and fecundity. Isopod morphology was quantified for each life stage, identifying shape transitions through ontogeny and sex change. Sex change in C. excisa was found to be driven by the absence of conspecific parasites within a host, where sex change only occurred in the first individual to arrive. To understand the infective stage of C. excisa parasite energetics and host detection mechanisms were tested. Parasites with free-living life stages have a narrow window to infect a host and have evolved a number of mechanisms to detect and locate a host. I used a series of energetic experiments to determine an infection window for free-swimming larvae (mancae) and behavioral response experiments testing both visual and chemical cues associated with host detection. Mancae were found to have a narrow infection window, where mancae began searching for a host as soon as they are born, but quickly switch to an ambush strategy to conserve energy. Mancae were also found to be responsive to both visual and chemical cues from its common fish host, as well as a non-host fish, indicating that chemical cues are used in host detection, but chemical specificity is not a mechanism that C. excisa uses to find its common host. The results from this study have implications to parasitic species and their hosts, as well as to other areas of study, including population and ecosystem dynamics. / text

Thesis (M.S.W.)--Smith College School for Social Work, Northampton, Mass., 2008. / Typescript. Includes bibliographical references (leaves 45-47).

No description available.