As a highly targeted species, red snapper have been overfished since the 1970’s. Inadequate monitoring and reporting of discard rates impedes regulatory measures which are in place to allow red snapper populations to reach a healthy, sustainable level. This study documented the relationship between morphometric measurements and otolith analysis of red snapper caught from a recreational headboat fishing exclusively in the GOM’s EEZ of the upper Texas coast. The collected data of this research show that of the 594 red snapper caught within the sample group, 76% of the fish were discarded; analysis of the lengths of these discarded fish show that 15.5% were of regulation size (16 inches) or larger, clear evidence that high-grading is occurring. The effort for the total amount of red snapper caught by each individual angler within the sample group was measured to determine on average, approximately two red snapper were caught per person, per hour. The size distribution ranged from 16 to 32 inches with a mean total length of 21.32 inches for retained fish while discarded fish ranged from 5.5 to 22.5 inches with a mean of 14.23. Weight distribution ranged from 1.5 to 18.5 pounds with a mean of 5.81 pounds for retained fish and 0.20 to 6 pounds with a mean of 1.57 pounds for discarded fish. Age distribution ranged from 3 to 14 years of age; red snapper can live over 50 years, however relatively none (2.42%) older than 10 years were present in the sample, demonstrating a highly truncated population. Because fecundancy increases with age in females, longevity extends reproduction potential for red snapper. Management of reef fishes, and red snapper in particular, are difficult due to variances in growth rates and habitat use, complex population structure, and increasing reproduction levels with maturity. Recommendations for management include implementing an educational outreach program, reducing effort and discard rates, lowing rates of exploitation, and creating a marine reserve. Future research should address the entire Texas coast population of for-hire vessels (charter and headboats) to obtain data on discard rates and age distribution of red snapper.

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 39-42). Also available on the World Wide Web.

Thesis--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 79-93).

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 97-105). Also available on the World Wide Web.

Thesis (Ph.D.)--Ohio University, August, 2006. / Title from PDF t.p. Includes bibliographical references.

This study reports the occurrence of daily rings in the otoliths of Oncorhynchus nerka fry and examines their relationship to growth. In experiment 1, sockeye salmon fry were collected from the Fulton River spawning channel at Babine Lake, British Columbia in May 1978. The fish were reared for 26 days in enclosures in the spawning channel and were sampled every seven to ten days. Sagittae were removed from 25 fish from each sample, and the growth rings in one otolith from each fish were counted. A regression of the number of rings on the number of days since capture showed that these rings are, on average, formed daily, beginning at the time of emergence. A number of possible technical and biological causes of variation in ring counts within and between samples are considered. In Experiment 2, sockeye salmon fry were reared in the laboratory from fertilized eggs taken in the fall of 1978 at the Weaver Creek spawning channel near Mission, British Columbia. A random sample of 64 of these fry was marked to enable identification of individuals. Each individual was weighed initially on June 6 or 8, again on July 6, and surviving fish were weighed a third time on July 20. After a final weighing, sagittae were removed and a standard otolith radius was determined by counting back the appropriate number of daily rings which corresponded to each weight. The regression of £n otolith radius on £n fish weight was linear, and had an R2 of 0.92, which demonstrates a relationship between the mean width of a daily ring in sockeye salmon fry sagittae, and a mean daily change in the weight of the fry. Using this regression line, we back-calculated the previous weight of the individual fish from the corresponding otolith radius and a latter fish weight and otolith radius and found the errors to be relatively small — in the order of 15 per cent. / Science, Faculty of / Zoology, Department of / Graduate

Depuis le début des années 1990, de nombreuses équipes de recherche ont consacré leurs travaux à étudier les effets des perturbateurs endocriniens (PEs) sur l'homme et les espèces animales. Plusieurs polluants libérés dans l’environnement tels que les pesticides, les herbicides, les plastifiants industriels ou les résidus de médicaments ont ainsi le potentiel de perturber les équilibres hormonaux des organismes, induisant ainsi de graves conséquences sur leur développement et leur reproduction. Pour lutter contre ces dommages, diverses réglementations spécifiques et des systèmes de criblages se mettent en place pour détecter ces molécules. Ces systèmes doivent être rapides et fiables et les poissons téléostéens comme le medaka ou le poisson zèbre constituent d'excellents modèles pour détecter la présence de ces molécules et étudier leurs effets in vivo. Durant cette thèse nous avons étudié l’impact de certains PEs sur le développement embryonnaire en utilisant le poisson zèbre et le médaka comme modèle. Nous avons pu caractériser l'action du Bisphenol A sur la formation des otholites de l’oreille interne du poisson zèbre. En alliant des approches pharmacologiques et génétiques, nous avons identifié le récepteur nucléaire orphelin ERR comme une nouvelle cible in vivo de cette molécule. En parallèle, nous avons développé des lignées transgéniques rapportrices de médaka permettant de détecter la présence de polluants à activités androgénique ou anti-androgénique ce qui accroît ainsi la gamme des outils disponibles pour évaluer la présence des PEs dans les effluents liquides. / Since the early 1990s, many research teams have devoted their work to study the effects of endocrine disruptors (EDCs) in humans and animal species. Many pollutants released into the environment such as pesticides, herbicides, industrial plasticizers or drug residues have the potential to disrupt bodies’ hormonal balances, thus inducing a severe impact on their development and reproduction. To fight against these damages, various specific regulations and screening systems are setting up to detect these molecules. These systems must be fast, reliable. Teleost fish such as medaka and zebrafish are excellent models to detect the presence of these molecules and study their effects in vivo. In this thesis, we studied the impact of certain EDCs on the embryonic development using zebrafish and medaka as models. We characterized the action of Bisphenol A on the otoliths formation in the inner ear of zebrafish. By combining genetic and pharmacological approaches, we identified the orphan nuclear receptor ERRγas a new target of this molecule in vivo. In parallel, we have developed reporter transgenic lines of medaka to detect the presence of pollutants containing androgenic or anti-androgenic activities and thereby increasing the range of tools available to assess the presence of EDCs in liquid effluents.

Urophycis mystacea, RIBEIRO, 1903, (Phycidae; Gadiformes) é uma espécie demerso-bentônica presente na plataforma externa e no talude da região Sudeste-Sul do Brasil. Desde 2001 é alvo das pescarias em águas profundas e seu estoque vem diminuído. A idade da espécie foi analisada em exemplares com comprimentos totais (Ct) entre 187 e 632 mm, através da contagem de anéis de 201 cortes de otólitos. A periodicidade (anual) e a época de formação dos anéis (outono) foram verificadas pela porcentagem relativa do tipo de borda. U. mystacea apresenta crescimento lento e longevidade moderada. Foram encontrados machos com 1 a 6 anos e fêmeas com 1 a 12 anos. Os parâmetros de crescimento foram obtidos pelos métodos de Ford-Walford e Iterativo dos Mínimos Quadrados. As equações de crescimento mais adequadas foram: Ct = 549.16 (1-exp-0.203(t-(-0.9)) para machos e, Ct = 738.08 (1-exp-0.134(t-(-1.08)) para fêmeas. O teste \"razão de máxima verossimilhança\" revelou diferenças significativas entre as curvas de machos e fêmeas. A relação entre variáveis morfométricas dos otólitos e a idade foi obtida (modelo potencial) e a robustez verificada pelo valor do coeficiente de determinação (R2). O peso apresentou maior robustez para predizer a idade dos exemplares / Urophicys mystacea, RIBEIRO, 1903 (Phycidae; Gadidae) is a demersalbenthic species present on the outer shelf and the slope of the South-Southeast region of Brazil. Since 2001 it has been a target fisheries on deepwater and its stock has been decreased. The age of the species was investigated in specimens with total lengths (Lt) between 187 and 632 mm by counting the rings of 201 otoliths slices. The periodicity (annual) and the time of ring formation (autumn) were verified by the relative percentage of the edge type. U. mystacea presents slow growth and moderate longevity. Males from 1 to 6 years and females from 1 to 12 years were found. Growth parameters were obtained by the methods of Ford-Walford and Iterative Least Squares. The most appropriate growth equations were: Lt=549.16 (1-exp-0.203 (t-(-0.9)) for males and Lt=738.08 (1-exp-0.134 (t-(-1.08)) for females. The likelihood test revealed significant differences between the male and female curves. The relationship between otolith morphometric variables and age was obtained (potential model) and its robustness was verified by the coefficient of determination (R2). The weight was more robust to predict the age of the specimens

Urophycis mystacea, RIBEIRO, 1903, (Phycidae; Gadiformes) é uma espécie demerso-bentônica presente na plataforma externa e no talude da região Sudeste-Sul do Brasil. Desde 2001 é alvo das pescarias em águas profundas e seu estoque vem diminuído. A idade da espécie foi analisada em exemplares com comprimentos totais (Ct) entre 187 e 632 mm, através da contagem de anéis de 201 cortes de otólitos. A periodicidade (anual) e a época de formação dos anéis (outono) foram verificadas pela porcentagem relativa do tipo de borda. U. mystacea apresenta crescimento lento e longevidade moderada. Foram encontrados machos com 1 a 6 anos e fêmeas com 1 a 12 anos. Os parâmetros de crescimento foram obtidos pelos métodos de Ford-Walford e Iterativo dos Mínimos Quadrados. As equações de crescimento mais adequadas foram: Ct = 549.16 (1-exp-0.203(t-(-0.9)) para machos e, Ct = 738.08 (1-exp-0.134(t-(-1.08)) para fêmeas. O teste \"razão de máxima verossimilhança\" revelou diferenças significativas entre as curvas de machos e fêmeas. A relação entre variáveis morfométricas dos otólitos e a idade foi obtida (modelo potencial) e a robustez verificada pelo valor do coeficiente de determinação (R2). O peso apresentou maior robustez para predizer a idade dos exemplares / Urophicys mystacea, RIBEIRO, 1903 (Phycidae; Gadidae) is a demersalbenthic species present on the outer shelf and the slope of the South-Southeast region of Brazil. Since 2001 it has been a target fisheries on deepwater and its stock has been decreased. The age of the species was investigated in specimens with total lengths (Lt) between 187 and 632 mm by counting the rings of 201 otoliths slices. The periodicity (annual) and the time of ring formation (autumn) were verified by the relative percentage of the edge type. U. mystacea presents slow growth and moderate longevity. Males from 1 to 6 years and females from 1 to 12 years were found. Growth parameters were obtained by the methods of Ford-Walford and Iterative Least Squares. The most appropriate growth equations were: Lt=549.16 (1-exp-0.203 (t-(-0.9)) for males and Lt=738.08 (1-exp-0.134 (t-(-1.08)) for females. The likelihood test revealed significant differences between the male and female curves. The relationship between otolith morphometric variables and age was obtained (potential model) and its robustness was verified by the coefficient of determination (R2). The weight was more robust to predict the age of the specimens

A total of 1814 Calamus proridens ranging from 76 mm - 361mm fork length (FL) were collected and processed along the central and northwest coasts of Florida between 2000 and 2007 to determine size, sex, age, and reproductive condition. Females ranged from 76-297 mm FL (mean FL=156 mm, n=1420), males ranged from 141-361 mm FL (mean FL=244 mm, n=297), and transitionals ranged from 131-307 mm FL (mean FL=207 mm, n=42). Sex ratios sorted by length class, age, and overall were significantly different from the 1:1 ratio for gonochoristic species (P is less than 0.0001). Sagittal otoliths (sectioned and whole) from 1438 C. proridens were used to determine age. Marginal increment analysis suggested that a single annulus is formed each year in the spring. Ages ranged from 0 to 10 years with 88% of the fish being between 0 and 4 years. Females ranged in age between 0 and 6 years, while males ranged between 1 and 10 years. Growth was rapid in the first two years and then began to slow down. The von Bertalanffy growth model fitted to all observed data was L(t)=306[1-e-0.254(t+1.69)]. The data were further broken down into central and southern strata and the von Bertalanffy growth model showed that fish in the central region grow larger than those in the southern region. Histological analysis confirmed that C. proridens are protogynous hermaphrodites with delimited type gonads. Estimates indicated that 50% of the females in the sample had transitioned into males by age 4 and a FL of 231 mm. Calamus proridens mature at a small size; 50% of the samples were mature by 132 mm and within the first year. The samples obtained indicated that the peak spawning season is in the spring. The presence of hydrated oocytes and post ovulatory follicles in the same ovary suggests that they are multiple spawners.