Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xiv, 235 p. : ill. (some col.), maps. Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--University of Western Australia, 2004. / Title from PDF title page (viewed on Mar. 3, 2006). Includes bibliographical references (p. 81-96).

Submitted by Leonardo Cavalcante (leo.ocavalcante@gmail.com) on 2018-04-26T15:24:14Z No. of bitstreams: 1 Arquivototal.pdf: 2102292 bytes, checksum: a57525d8f4e150a95eb60a9e574ddd8e (MD5) / Made available in DSpace on 2018-04-26T15:24:14Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 2102292 bytes, checksum: a57525d8f4e150a95eb60a9e574ddd8e (MD5) Previous issue date: 2016-05-28 / This study is a retrospective of five years of experimental cultivation of a seahorse specie Hippocampus reidi. The aim was to characterize and quantify the main diseases of the specie in captivity, associated with water quality parameters in two types of systems (SCF - Closed System Circulation and SI – Isolated unfiltered system), as well an assessment of bacterial infections associated with skin lesions and water during one year. It was recorded 192 ill seahorses in the experimental cultivation over the five years in which individuals with dermatitis were the most frequent, occurring in 46.3% of cases and leading to severe medical conditions as epidermal ulceration, whitish spots along the entire organism and tissue desquamation. Other illnesses as gas bubbles diseases, balance difficulties and sudden death were also observed but to a lesser extent. Samples of ulcerative lesions were collected, using swabs, between april/14 and april/15 of two 2 classes of lesions in the tail and one type in the brood pouch from experimental cultivation seahorses. Samples of water from the water distribution system were also gathered. A total of 119 bacterial strains were isolated. Isolated Bacteria were identified using the 16S sRNA gene according to similarity searches in databases NCBI (National Center for Biotechnology Information) and RDP (Ribosomal Database Project). Among isolated bacterial strains, it was identified 12 species of Bacteria, distributed in seven families. The main families identified in skin lesions of Hippocampus reidi were Micrococcaceae (38.2%), Vibrionaceae (25.5%) and Bacillaceae (23.4%), while the main families founded in water were Pseudoalteromonadaceae (51,4%) and Bacillaceae (34,2%). The number of ill individuals in maintaining systems were directly associated with increased levels of nitrite and ammonia, as well pathogenic bacteria or opportunistic pathogens. / O presente estudo é uma retrospectiva de 5 anos de cultivo experimental de cavalos-marinhos da espécie Hippocampus reidi, caracterizando e quantificando as principais doenças da espécie em cativeiro em associação com parâmetros da qualidade da água em dois tipos de sistemas de manutenção da espécie (SCF – Sistema de Ciculação Fechada e SI – Sistema de aquários isolados sem filtragem) e uma avaliação de infecções bacterianas associadas a lesões cutâneas e a água durante o período de um ano. Foram registrados 192 cavalos-marinhos doentes no cultivo experimental ao longo dos 5 anos, nos quais indivíduos com dermatites foram os mais frequentes, representando 46,3% dos casos, gerando quadros clínicos severos que incluem lesões ulcerativas, manchas esbranquiçadas ao longo do corpo e descamação de tecido. Doenças das bolhas, dificuldades de equilíbrio e morte súbita foram outras doenças observadas, porém em menor proporção. Foram coletadas, entre abril/2014 e abril/2015, amostras de esfregaço por meio de swab de 2 tipos de lesões ulcerativas na região da cauda e 1 tipo de lesão ulcerativa na região da bolsa incubadora de cavalos-marinhos provenientes do cultivo experimental e amostras de água provenientes dos sistemas de distribuição (SD) de água, das quais totalizam 119 isolados bacterianos. As cepas isoladas foram identificadas a partir do sequenciamento do gene 16S sRNA por meio de buscas de similaridade nos bancos de dados NCBI (National Center for Biotechnology Information) e RDP (Ribosomal Database Project). Dentre os isolados, foram identificadas um total de 12 espécies bacterianas distintas, distribuídas em 7 famílias, cujas famílias mais abundantes em lesões cutâneas foram Micrococcaceae (38,2%), Vibrionaceae (25,5%) e Bacillaceae (23,4%) e em isolados da água Pseudoalteromonadaceae (51,4%) e Bacillaceae (34,2%). O número de indivíduos doentes nos sistemas de manutenção está diretamente associado a aumento nos níveis de nitrito e amônia e de bactérias patogênicas ou patogênicas oportunistas.

Understanding the processes that govern mating behaviors is a fundamental goal of evolutionary biology and behavioral ecology. Population-level patterns of mate acquisition and offspring production, otherwise known as the genetic mating system, play a central role in the sexual selection on morphological and behavioral traits and may facilitate speciation. The central hypothesis of this research is that variation in environmental conditions, such as temperature, turbidity, and habitat, and demographic influences such as population density, sex ratios and temporal availability of mates, may limit mating and reproductive success in a predictive manner. Therefore the goal of this dissertation is to examine the contributions of geographic and temporal variation on the plasticity of the genetic mating system in two species of pipefish. The first study examined whether meaningful variation in the genetic mating system exists between two natural populations of the dusky pipefish, Syngnathus floridae. Results of this investigation provide evidence that the genetic mating system differs among different geographic locations. The second study considered the relative contributions of environmental conditions and population demographics on differences in the genetic mating system of dusky pipefish from five natural populations. The results of this investigation show strong trends for demographic and environmental factors to strongly influence the genetic mating system between populations. The third study considered how variation in the number of available mates predicts the outcome of sexual selection during the course of a breeding season in the broad-nosed pipefish, Sygnathus typhle. The results of this study indicate a strong influence of the operational sex ratio on the genetic mating system. In addition to these studies, a study was conducted to investigate whether phylogeographic relationships may be responsible for geographic variation in the genetic mating system of the dusky pipefish of pipefish. Mitochondrial DNA analysis does not substantiate subspecies designations for this species and microsatellite analysis show a clear pattern of isolation by distance. Taken together, these studies significantly enhance the understanding of how mating systems are organized over broad environmental gradients and temporal/spatial scales and to the evolution of sexual selection on the whole.

Animals experience variation in their environment because of natural changes. However, due to anthropogenic disturbance, the speed and severity of these changes have recently increased. This thesis investigates how reproductive behaviours may be affected by human induced environmental change. In specific, I investigate how visual and chemical changes in the aquatic environment, caused by eutrophication, affect mating systems and sexual selection in fish. Broad-nosed- and straight-nosed pipefish, which both have been studied in detail for a long period, were used as model organisms. These two species are particularly suitable model organisms since they perform complex courtship behaviours, including the advertisement of ornaments and a nuptial dance. Further, two distinct populations were studied, one on the Swedish west coast and one in the Baltic Sea, as these two locations vary in the degree and extent of environmental disturbance, in particular turbidity. I found that changes in the visual environment had no impact on the development of female sexual ornaments in these sex-role reversed pipefishes, but it hampered adaptive mate choice. Turbidity also had a negative effect on reproductive success in the Baltic Sea population. Changes in the chemical environment in the form of increased pH reduced the probability to mate, while hypoxia did not alter mating propensity. However, hypoxic water delayed the onset of both courting and mating. Hence, human induced change in aquatic environments may alter the processes of sexual selection and population dynamics.

Understanding the processes that govern mating behaviors is a fundamental goal of evolutionary biology and behavioral ecology. Population-level patterns of mate acquisition and offspring production, otherwise known as the genetic mating system, play a central role in the sexual selection on morphological and behavioral traits and may facilitate speciation. The central hypothesis of this research is that variation in environmental conditions, such as temperature, turbidity, and habitat, and demographic influences such as population density, sex ratios and temporal availability of mates, may limit mating and reproductive success in a predictive manner. Therefore the goal of this dissertation is to examine the contributions of geographic and temporal variation on the plasticity of the genetic mating system in two species of pipefish. The first study examined whether meaningful variation in the genetic mating system exists between two natural populations of the dusky pipefish, Syngnathus floridae. Results of this investigation provide evidence that the genetic mating system differs among different geographic locations. The second study considered the relative contributions of environmental conditions and population demographics on differences in the genetic mating system of dusky pipefish from five natural populations. The results of this investigation show strong trends for demographic and environmental factors to strongly influence the genetic mating system between populations. The third study considered how variation in the number of available mates predicts the outcome of sexual selection during the course of a breeding season in the broad-nosed pipefish, Sygnathus typhle. The results of this study indicate a strong influence of the operational sex ratio on the genetic mating system. In addition to these studies, a study was conducted to investigate whether phylogeographic relationships may be responsible for geographic variation in the genetic mating system of the dusky pipefish of pipefish. Mitochondrial DNA analysis does not substantiate subspecies designations for this species and microsatellite analysis show a clear pattern of isolation by distance. Taken together, these studies significantly enhance the understanding of how mating systems are organized over broad environmental gradients and temporal/spatial scales and to the evolution of sexual selection on the whole.

Syngnathidae (seahorse, pipefish, pipehorses & seadragons) are highly visual feeders with different species feeding on specific types of prey, a behaviour that has been related to snout length. Worldwide, many species have become threatened by habitat destruction, collection for the aquarium trade and exploitation for traditional medicine, as well as recreational and commercial bycatch. Attempts to establish aquaculture programs have been of limited success. Little is known about their visual capabilities in detail. The visual systems of fishes are known to have evolved specific adaptations that can be related to the colour of water in which they live and specific visual tasks such as predator detection and acquisition of food. This study examined the ocular and retinal morphology, photoreceptor structure and spectral sensitivity of adult individuals of a local pipefish (S. argus), local seahorse (Hippocampus subelongatus) which both inhabit green water seagrass beds, and a tropical species of seahorse (Hippocampus barbouri) from blue water coral reefs. Some juveniles were also investigated. Accordingly, we developed an understanding of the features that are common to all syngnathids and those that have evolved for specific environments. Cryosections of the eyes were taken to determine morphological distinctions of this group. Lens characteristics measured using a spectrophotometer determined 50% cut-off wavelengths below 408nm for all 3 species, hence no transmission of UV light to the retina. Histological examination determined a cone dominated fovea in the ventro-temporal retina and very large rods concentrated in the peripheral retina and adjacent to the optic nerve. Microspectrophotometry measured the absorption characteristics of the visual pigments within the photoreceptors showing the presence and maximum sensitivity (λmax) of rods, SWS single cones, and a broad, complex array of LWS double/twin cones. The results are discussed in relation to the light environment inhabited by each species and their feeding requirements. The implications for the design of suitable light environments for aquarium and aquaculture programs for the Syngnathidae are also discussed. Rearing success of this family of fish, for both the aquarium trade and re-stocking programs, would be advised to take lighting regimes and specifics of the animals’ vision into account

The sex-role reversal and male pregnancy found in syngnathids are highly unusual traits in vertebrates. Reproductive hormones likely influence development and regulation of these traits. However, very few studies have examined the underlying hormonal mechanisms that mediate female competitive behavior and male pregnancy. New methodologies and better husbandry practices have made such studies more feasible in recent years. Research on a relatively small number of species has suggested that androgens are likely regulators of spermatogenesis and the development of the male brood pouch prior to pregnancy. Androgens are also potential candidates for mediating sex-role reversed behavior in female syngnathids. The goal of this dissertation was to examine the role of androgens in the male reproductive cycle and female intrasexual competitive behavior in the sex-role reversed Gulf pipefish, Syngnathus scovelli. From review of the literature, I developed a model for the hormonal regulation of the male reproductive cycle in seahorses. I predicted that androgens would be low during the early stages of pregnancy and increase during the end of pregnancy as males go through another cycle of spermatogenesis in preparation for the next mating event. My study of 11-ketotestosterone and testis mass across the reproductive cycle in male S. scovelli supported this model. I also conducted several studies on the role of androgens in female competitive behavior. I determined that treatment with 11-ketotestosterone the evening prior to an intrasexual interaction resulted in an increase in competitive behavior in large over small test females. Conversely, treatment with 11-ketotestosterone one hour prior to an intrasexual interaction resulted in a decrease in competitive behavior in large over small females when stimulus female behavior was controlled. A comparative study of competitive and courtship behavior in S. scovelli and the closely related S. floridae suggested that sexual selection has affected competitive and courtship behavior in both males and females of these species. The diversity of reproductive patterns exhibited by syngnathids suggests that they will provide a unique opportunity to assess how hormonal regulation of reproductive behavior and function has evolved within this lineage.