Made available in DSpace on 2014-06-12T15:04:26Z (GMT). No. of bitstreams: 2 arquivo1242_1.pdf: 1256601 bytes, checksum: 4d438f7f807b6f8766533b2fef42fb04 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A raia-roxa, Pteroplatytrygon violacea, é o único membro da família Dasyatidae com hábitos totalmente pelágicos. O principal objetivo deste estudo foi avaliar a periodicidade de formação dos anéis etários e à estimação dos parâmetros de crescimento, através do exame da deposição de marcas de crescimento nas vértebras desta espécie. No total, foram capturados 348 espécimes entre maio de 2005 e maio de 2008, sendo 120 fêmeas e 228 machos, como fauna acompanhante na pesca dos atuns e afins no atlântico Sul equatorial. A análise do incremento marginal apontou para a formação de uma banda de crescimento por ano. As larguras do disco (LD) variaram entre 30,6 cm e 63,2 cm para as fêmeas e entre 26.6 cm e 59,6 cm para os machos. A composição etária da amostra de machos é de indivíduos que variam desde 0 a 9 anos e fêmeas de 0 a 10 anos. Os três parâmetros derivados do modelo de crescimento de von Bertalanffy foram para fêmeas: L∞ (cm) = 91,53, k = 0,073, t0 = -5,26; para machos: L∞ (cm) = 78,53, k = 0,10, t0 = - 4,16. Estes valores são um dos mais baixos reportados para raias Myliobatiformes e indicam taxas de crescimento lento na comparação com elasmobrânquios em geral

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-31T13:55:01Z No. of bitstreams: 1 2011 - Luciane Marins Bed?.pdf: 3568218 bytes, checksum: dd8b031aa116daa6b17232d9004b198b (MD5) / Made available in DSpace on 2016-08-31T13:55:01Z (GMT). No. of bitstreams: 1 2011 - Luciane Marins Bed?.pdf: 3568218 bytes, checksum: dd8b031aa116daa6b17232d9004b198b (MD5) Previous issue date: 2011-06-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This study was conducted in the Jabaquara mangrove, Paraty, Rio de Janeiro, with the aim of investigate the spatial distribution, population biology of brachyuran species and somatic growth of Uca rapax (Smith, 1870) (Crustacea, Decapoda, Ocypodidae) in the Jabaquara`s mangrove/Paraty - RJ. Sampling was performed in two grids from July 2007 to June 2008, using the capture effort per unit. Two collectors captured the crab monthly, during 15 minutes in low tide. Sediment samples from all the selected plots were collected to determinate particle size and organic matter. Air temperature and salinity also were measured. Eight species of brachyuran were captured, U. rapax, U. thayeri, U. vocator, U. uruguayensis, U. cumulanta, Neohelice granulata, Ucides cordatus and Eurytium limosum. U. rapax was the most abundant species in number of individuals and ovigerous females. The results indicated that distribution of the species was influenced by abiotic factors. The most species were more abundant in the inner portions of the mangroove and near of the sea. The ovigerous females of U. rapax were more abundant in the inner portions of the mangroove and near from the sea and N. granulata more distant from the sea. U. rapax showed a positive correlation with organic matter. U. thayeri, U. uruguayensis and E. limosum negatively correlated to distance from the sea. U. vocator showed positive correlation for sand and organic matter and negatively correlated to distance from the sea. U. cumulanta was positively correlated to sand. The ovigerous females of U. rapax showed a positive correlation to air temperature and organic matter. N. granulata and U. cordatus were the species more versatile in habitat colonization. The size of the crabs in the Jabaquara?s Mangrove were the smallest size than those found in other Brazilian mangroves. However, the males attained a larger size than females. The size frequency distribution was unimodal for the most species. In general, the males were predominant in all size classes, and more evident in larger classes. The sex ratio differ significant from 1:1 proportion (male: female), which most of the time dislocated for males. The most species showed a seasonal reproductive period, with more abundance of ovigerous females during the spring and summer. The growth curves in width (mm) for males and females were described by the equations: LC= 24,28 [ 1- e -0,0038(t-2,8) ] and LC= 22,0 [ 1- e -0,0031(t-2,3)], respectively. The males reach larger sizes and a higher growth rate than females. The longevity was estimated at three years for males and four years for females / Este trabalho foi realizado no manguezal de Jabaquara, em Paraty, Rio de Janeiro com o objetivo de analisar a distribui??o espacial, a biologia populacional das esp?cies de braqui?ros e o crescimento som?tico de Uca rapax (Smith, 1870) no manguezal de Jabaquara/ Paraty ? RJ. As coletas foram realizadas em dois grides de julho 2007 a junho2008, utilizando-se a t?cnica de esfor?o por unidade de captura. Dois coletores capturaram os caranguejos mensalmente, durante 15 minutos em per?odo de mar? baixa. Amostras de sedimento foram coletadas nas parcelas selecionadas, para determinar o tamanho das part?culas e mat?ria org?nica e a temperatura do ar e a salinidade tamb?m foram tomados. Foram capturadas oito esp?cies de braqui?ros: U. rapax, U. thayeri, U. vocator, U. uruguayensis, U. cumulanta, Neohelice granulata, Ucides cordatus e Eurytium limosum. U. rapax foi ? esp?cie mais abundante em n?mero de indiv?duos e de f?meas ov?geras. Os resultados revelaram que a distribui??o das esp?cies foi influenciada pelos fatores abi?ticos. A maioria das esp?cies foi mais abundante nas parcelas mais internas do manguezal e pr?ximas ao mar. As f?meas ov?geras de U. rapax e N. granulata foram mais abundantes nas parcelas mais internas do manguezal e mais pr?ximas e mais distantes do mar, respectivamente. U. rapax apresentou correla??o positiva para mat?ria org?nica. U. thayeri, U. uruguayensis e E. limosum apresentaram correla??o negativa para dist?ncia do mar. U. vocator apresentou correla??o positiva para areia e mat?ria org?nica e correla??o negativa para dist?ncia do mar. U. cumulanta apresentou correla??o positiva para areia. As f?meas ov?geras de U. rapax apresentaram uma correla??o positiva para temperatura do ar e mat?ria org?nica. N. granulata e U. cordatus foram as esp?cies mais vers?teis em formas de colonizar ambientes. Com rela??o ao tamanho dos indiv?duos, observou-se que os braqui?ros do Manguezal de Jabaquara, de maneira geral, apresentam tamanhos maiores que os encontrados em outros manguezais do Brasil. Contudo, os machos atingiram tamanhos maiores que as f?meas. A distribui??o de freq??ncia em classes de tamanho foi unimodal para a maioria das esp?cies. De maneira geral, os machos foram predominantes em todas as classes de tamanho, sendo mais evidente nas maiores classes. A raz?o sexual diferiu significativamente da propor??o 1:1, estando na maioria das vezes deslocada para os machos. A maioria das esp?cies apresentou um per?odo reprodutivo sazonal, ocorrendo maior abund?ncia de f?meas ov?geras na primavera e no ver?o. O modelo de von Bertalanffy foi utilizado para a descri??o do crescimento. As curvas de crescimento em largura (mm) para machos e f?meas de U. rapax, foram descritas pelas equa??es: LC= 24,28 [ 1- e -0,0038(t-2,8) ] e LC= 22,0 [ 1- e -0,0031(t-2,3)], respectivamente. Os machos apresentaram uma taxa de crescimento maior do que as f?meas. A longevidade foi estimada em 3 anos para os machos e 4 anos para as f?meas.

Made available in DSpace on 2015-03-26T13:32:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 834675 bytes, checksum: cbd61abff31c731b6961bd0ef022cffa (MD5) Previous issue date: 2012-02-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Studies that use hierarchical cluster analysis have a problem in determining the optimal number of groups due to lack of objective criteria. Researches involving the adjustment of nonlinear models to data on growth or survival, in which the main interest is to determine how many curves are needed to describe the behavior of the individuals analyzed, use this technique. Some researchers use indices BSS (Between-group Sum of Squares), SPRSQ (Semi-partial R-Squared), RMSSTD (Root Mean Square Standard Deviation), RS (R-Squared) and Mojena method, as a means of assistance in this decision. However, it is not known which one is the best choice to determine that value. The comparison of these statistics was the aim of this study. The entire methodology used the Ward s method to cluster the observations, the von Bertalanffy model to fit the curves, and a specific function, based on the law of cosines and the idea of the Modified Maximum Curvature Method, to calculate the number of groups indicated by the indices. In chapter 1, a real case study was developed. The data set had seven animal growth curves, forming three groups. After grouping the parameter estimates and the calculation of statistics, it was found that only the index SPRSQ pointed to the correct number of groups. Using a function to re-scale the axis of the indices according to the axis of the number of groups, to improve the results obtained, only RMSSTD did not indicate the expected value. Chapter 2 describes the use of simulation to find out which of the statistics mentioned had the highest percentage of accuracy in determining the optimal number of groups in two cases. In the first one, the observations came from a single generator curve and, in the other, the individuals belonged to three different populations. In the case of a single curve, the RS index pointed to the optimal number of groups in most cases. For the case in which there were three different populations, the Mojena method was the one that indicated the right number of groups more often. In these cases, the use of the function that re-scales the axes did not show efficiency to improve the percentage of correct indices. In general, the indices RS and SPRSQ were the most appropriate to assist in determining the optimal number of groups. / Estudos envolvendo análise de agrupamento hierárquico encontram um problema na hora de determinar o número ótimo de grupos, devido à falta de critérios objetivos. Pesquisas que envolvem o ajuste de modelos não-lineares a dados de crescimento ou de sobrevivência, cujo interesse principal é saber quantas curvas são necessárias para descrever o comportamento dos indivíduos analisados, utilizam dessa técnica. Como forma de auxiliar essa decisão, alguns pesquisadores recorrem aos índices BSS (Between-group Sum of Squares), SPRSQ (Semi-partial R-Squared), RMSSTD (Root Mean Square Standard Deviation), RS (R-Squared) e ao método de Mojena. Entretanto, não se sabe qual deles é a melhor escolha para determinação desse valor. A comparação dessas estatísticas foi o objetivo desse trabalho. Toda a metodologia utilizou o método de Ward para fazer o agrupamento das observações, o modelo de von Bertalanffy para o ajuste das curvas, e uma função própria, baseada na lei dos cossenos e na ideia do Método da Máxima Curvatura Modificado, para calcular o número de grupos indicado pelos índices. No capítulo 1 foi feito o estudo de caso real. O conjunto de dados possuía sete curvas de crescimento animal, que formavam três grupos. Após o agrupamento das estimativas dos parâmetros e o cálculo das estatísticas, foi constatado que apenas o índice SPRSQ apontou o número de grupos correto. Usando uma função que re-escalona o eixo dos índices de acordo com o eixo do número de grupos, para melhorar os resultados obtidos, apenas o RMSSTD não indicou o valor esperado. O capítulo 2 descreve o uso da simulação para descobrir qual das estatísticas citadas possuía maior porcentagem de acerto quanto à determinação do número ótimo de grupos em dois cenários. No primeiro, as observações provinham de uma única curva geradora e no outro, os indivíduos pertenciam a três populações diferentes. Para o caso de uma única curva, o índice RS foi o que apontou o número ótimo de grupos na maioria dos casos. Para o cenário onde se possuía três populações diferentes, o método de Mojena foi o que acertou o número de grupos mais vezes. Nesses cenários, o uso da função que re-escalona os eixos não mostrou eficiência para melhorar a porcentagem de acertos dos índices. De modo geral, os índices RS e SPRSQ mostraram-se os mais indicados para auxiliar na determinação do número ótimo de grupos.

Les paramètres de croissance de poissons pélagiques et démersaux ont été étudiés durant la période de 1990 à 2015 dans le but d’examiner l’impact de facteurs biotiques comme la densité-dépendance, le recrutement, la mortalité totale et de facteurs abiotiques tels que l’intensité d’upwelling, la température et la concentration en chlorophylle a. Les paramètres d’histoire de vie des espèces peuvent varier selon les espèces, d’une région à l’autre, et dans le temps au sein d’une même région en raison de leur plasticité et de la pression de la pêche. Une comparaison inter-espèces et inter-régions a été réalisée. Le modèle non linéaire à effets mixtes a été utilisé pour différentes populations de l’Océan Atlantique afin d’établir les paramètres de croissance aux niveaux individuel et de la population. Les variations des paramètres de croissance d’une sélection d’espèces ont été mises en corrélation avec des facteurs biotiques et abiotiquesLes espèces (Sardinella aurita, sardinelle ronde, Atherinella brasiliensis, tinicalo, Merlangius merlangus, merlan, Melanogrammus aeglefinus, églefin et Solea solea, sole) montrent des réponses différentes aux facteurs biotiques et abiotiques. Au niveau spatial pour le merlan et l’églefin, la croissance est affectée par la latitude et la température, tandis qu’au niveau temporel la croissance du merlan est affectée par la température et la densité. Il y avait un intérêt pour savoir si les variables morphométriques et le diamètre de l’otolithe de tinicalo étaient de bons indicateurs de la croissance : c’est la longueur standard qui a présenté / The impact of biotic factors such as density-dependent processes, recruitment, total mortality, and abiotic factors such as upwelling intensity, temperature and chlorophyll a concentration on the variation of growth parameters of pelagic and demersal fish were studied during the periods 1990 - 2008 (pelagic) and 1971 - 2015 (demersal). Life history parameters vary according to the species and from one region to another and over time within a given area because of their plasticity and the high fishing pressure. Interspecies and inter-regional comparison were carried out. Non-linear mixed effects models were used on different fish species of the Atlantic Ocean in order to estimate the growth parameters at the individual and population levels. Variations in growth parameters of selected species were correlated with biotic and abiotic factors.Selected species (Sardinella aurita, round sardinella, Xenomelaniris brasiliensis, tinicalo, Merlangus merlangus, whiting, Melanogrammus aeglefinus, haddock and Solea solea, sole) showed different responses to biotic and abiotic factors. Regardind the spatial component for whiting and haddock, the variation of growth parameters was affected by latitude and temperature. Concerning the temporal component, whiting was affected by temperature and density-dependent processes. There was also an interest to know if the morphometric variables and the diameter of the otolith of Atherinella brasilensis were good growth indicators. Among the morphometric parameters examined, the standard length-Age relationship showed the best fit (r2 = 0.90), foll

The whale shark (Rhincodon typus) has a global distribution in warm to warm temperate oceans, and is a species of high conservation concern currently categorized as Endangered on the International Union for Conservation of Nature (IUCN) Red List. Despite its dire conservation status and concerns about the growing number of ecotourism interactions with this species worldwide, relatively little information is available on key aspects of whale shark biology such as growth rates, reproductive rates, survival rates and breeding habitats. In particular, critical information such as age and growth of whale sharks is needed to improve the management and conservation of this species. Robust knowledge of life history parameters is needed to improve demographic models for whale sharks and enable better evaluation of their vulnerability to fishing pressures and recovery from population declines. Whale sharks are well known to form aggregations in specific locations, with one such site being the South Ari Atoll in the Maldives. My study aimed to expand knowledge of the population dynamics, including age and growth, of whale sharks at the South Ari Atoll by calculating growth parameters and rates from encounters with free-swimming sharks over a decade (April 2006 to May 2016). A total of 1545 encounters with 125 individual sharks were recorded during this time period. To obtain the most accurate information on the sizes of whale sharks, total lengths were estimated by three different measurement methods (visual, laser photogrammetry, and tape), and linear regression was utilized to investigate how these different methods compared to one another. The results showed that visual estimates tended to underestimate sizes of the larger sharks, and laser and tape measurements yielded similar results to one another (R2 = 0.824). New sharks observed at the South Ari Atoll during the study period were significantly smaller than returning sharks, suggesting that young sharks may be recruited to the South Ari Atoll, where they stay and grow until reaching maturity before leaving the area. To the best of my knowledge, my study is the first to infer growth parameters and rates from measurements of free-swimming whale sharks. Estimates of von Bertalanffy growth parameters for combined sexes, calculated from 180 encounters with 44 individual sharks (Males (n=40), Females (n=4), TL=3.16 m – 8.00 m), yielded an L¥ of 19.56 and a k value of 0.021. Analyzing 177 encounters with 40 male sharks (TL=3.16 m - 8.00 m) exclusively provided an L¥ of 18.08 and a k value of 0.023. These values correspond to a male age at maturity of ~25 years and a longevity of ~140 years, exceeding those estimated for whale sharks captured off Taiwan based on analysis of biannual vertebral rings (male maturity =17 years; longevity (combined sexes) = 80.4 years). There have been few growth studies, mainly from vertebral analysis, that have produced wide ranges in L¥ (14 – 20.5) and k values (0.017 – 0.037). These differences underscore the need for additional regional studies to obtain population specific estimates of these key life history parameters.

Pteroplatytrygon violacea is the only member of the Dasyatidae family that exhibits an entirely pelagic behavior. Age, growth and reproduction characteristics were estimated for western north Atlantic populations, where it is a common bycatch species of commercial pelagic longline fisheries targeting swordfish and tuna. Ages were assigned by counting band-pair deposition on vertebral centra sections. An annual pattern of band-pair deposition was validated through marginal increment analyses. Age estimates ranged from 2.5 to 8 years for males and 3 to 10 years for females. The von Bertalanffy growth model, a modified form of the von Bertalanffy, a two-parameter form of the von Bertalanffy with a fixed length-at-birth, the Gompertz growth model and a logistic model were fitted to sex-specific observed size-at-age data. Models were fitted using maximum likelihood estimation and nonlinear least squares methods. Resulting models were evaluated based on biological rationale and Akaike’s information criteria. All growth models yielded similar estimates, however the two-parameter Von Bertalanffy growth model provided the best fit for both males (L∞ = 54.79 cm (Disc width, DW) and k = 0.44 year-1) and females (L∞ = 65.56 cm (DW) and k = 0.26 year-1). Reproduction was determined by assessing maturity and reproductive stages. Sexual dimorphism was observed where females grew significantly larger than males. Males were determined mature when DW was greater than 38cm when claspers were shown to be fully calcified and vas deferens were coiled. Females were determined to reach maturity between 40 and 50 cm DW although a lack of smaller sized females prevented a more accurate estimate of first maturity. Females were observed pupping near term embryos ranging from 14.2 to 16 cm DW in mid-July and late September indicating possibilities of two litters per year. Large oocytes where observed in an ovary in a female with a uterus containing seven eggs with a mean mass of 2.80 g indicating that P. violacea exhibit vitellogenesis proceeding simultaneously with gestation. A clear seasonality for the reproductive cycle was not apparent however it seems parturition occurs in late spring and early fall when conditions are optimal for neonate survival. Data on the age, growth and reproduction of western north Atlantic populations of P. violacea will contribute to the lack of life history characteristics of this common bycatch species.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-20T13:51:05Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação CD Biblioetca Denise Moraes 2016 FINAL.pdf: 2561125 bytes, checksum: 30370d4b25d98afe00850c78927ba185 (MD5) / Made available in DSpace on 2017-02-20T13:51:05Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação CD Biblioetca Denise Moraes 2016 FINAL.pdf: 2561125 bytes, checksum: 30370d4b25d98afe00850c78927ba185 (MD5) Previous issue date: 2016-08-19 / FACEPE / O conhecimento dos parâmetros de crescimento e mortalidade em braquiúros é fundamental para a compreensão da sua dinâmica e para o manejo de suas populações. Neste sentido, foram estimados os parâmetros de crescimento e mortalidade para Cardisoma guanhumi Latreille, 1825 (guaiamum), uma espécie com elevada importância socioeconômica no nordeste brasileiro e atualmente considerada pelo Ministério do Meio Ambiente como Criticamente em Perigo de extinção. As amostragens foram efetuadas durante um ano, entre abril de 2015 a março de 2016, na margem superior do mangue do CMA/ICMBio/CEPENE na ilha de Itamaracá, Pernambuco, Brasil. Foram capturados, medidos e pesados 1078 indivíduos (572 machos e 506 fêmeas). Destes, 291 indivíduos foram marcados com microchips PIT ("Passive Integrated Transponder"), para determinação dos parâmetros de crescimento através dos incrementos de peso e tamanho e do crescimento individual. Para a análise dos dados, foram utilizados o método ELEFAN I (baseado na distribuição de frequência de largura de carapaça de 1078 indivíduos), inserido no pacote computacional Fisat II e através da função GrowthTraject (baseada em incrementos individuais de 291 indivíduos marcados com PITs, utilizando o pacote fishmethods (Ambiente de programação “R”). Os indivíduos de C.guanhumi apresentaram largura da carapaça entre 20,9 e 70,0 mm (média: 43,45 mm, desvio padrão: 8,53 mm, mediana: 44,05 mm) o peso total entre 4 e 162 g (média: 45,85 g, desvio padrão: 25,34 g, mediana: 44,0 g). Não houve diferenças significativas, em tamanho médio e peso médio, entre machos e fêmeas. Os parâmetros de crescimento estimados com a função GrowthTraject para 130 incrementos (machos e fêmeas) foram: Linf (tamanho assintótico) = 108,03 mm (largura da carapaça); K (coeficiente de crescimento) = 0,145 ano-1. A Mortalidade total (Z) da população, estimada pelo método Length – converted Catch Curve (pacote FISAT II) usando os parâmetros de crescimento do GrowthTraject foi de = 2,39 ano-1. Não ocorrem capturas comerciais nesta área fechada, portanto, este valor equivale à mortalidade total e natural (Z=M). A idade dos indivíduos capturados variou de 1,49 anos (20,9mm) a 7,02 anos (70,0mm). O recrutamento, calculado no pacote FISAT II e estimado através da presença de juvenis, mostrou-se contínuo durante todo o ano. Os métodos de análises de frequência e comprimento inseridos no pacote FISAT (Bhattacharya, ELEFAN I e Shepherd’s) não foram capazes de determinar os parâmetros de crescimento, provavelmente devido ao crescimento lento e recrutamento contínuo durante todo ano. O tamanho total da população no manguezal do CMA foi estimado em 1262 indivíduos (+- 401ind.), baseado nos dados de marcação e recaptura. / Knowledge on the growth parameters and mortality in brachyuran is fundamental to the understanding of the dynamics and management of their populations. Growth and mortality parameters were estimated for Cardisoma guanhumi Latreille, 1825 (locally known as”guaiamum”), a species with high socio-economic importance in northeastern Brazil and currently considered by the Ministry of the Environment as Critically Endangered of Extinction. The samples were taken over one year, from April 2015 to March 2016, at the upper margin of a small, isolated mangrove patch at CMA-ICMBio-CEPENE on Itamaracá Island, Pernambuco, Brazil. A total of 1078 individuals (572 males and 506 females) were captured, measured and weighed. Of these, 291 individuals were marked with PIT tags (Passive Integrated Transponder tags), as to determine the growth parameters through the analysis of the increments in weight and size and individual growth. For the data analysis, we used the ELEFAN I method (based on the frequency distribution of carapace width 1078 individuals), inserted into the computer package FISAT II and through the GrowthTraject function (based on individual increments of 291 individuals marked with PIT tags, using the fishmethods package ("R” Environment). C. guanhumi showed carapace widths between 20.9 and 70.0 mm (mean: 43,45 mm, standard deviation: 8,53 mm, median: 44,05 mm) and total weight between 4 and 162 g (mean: 45,85 g, standard deviation: 25,34 g, median: 44,0 g). There were no significant differences in average size and average weight between males and females. Growth parameters estimated with the fishmethods package, based on 130 increments (males and females), were: L∞ (asymptotic carapace width) = 108.03 mm; K (coefficient growth) = 0.145 y-1. Total mortality (Z) of the population, estimated through the Length-converted catch Curve method (FISAT II package), using the fishmethods growth parameters, was 2.39 y-1. Since this is a restricted area without regular commercial catches, so this value is roughly equivalent to the total and natural mortality (Z = M). The age of the individuals captured ranged from 1.49 years (20,9 mm) to 7.02 years (70,0 mm). Recruitment, calculated in FISAT II package and estimated by the presence of juveniles, showed to be continuous throughout the year. The methods of length-frequency analysis inserted in the FISAT package (Bhattachary of protective measures for this species.

The growth rate of a fish is a fundamental function used in stock assessments to estimate the population size and the fishery pressure affecting the species. There has been recent debate within the stock assessment community regarding which type of growth model best represents the true growth rate of yellowfin tuna (Thunnus albacares), in the Atlantic Ocean; specifically, should assessments use a traditional von Bertalanffy growth curve or a so-called “two-stanza” growth curve, which combines one growth rate for smaller individual tuna and another for larger sizes. Using a simulated population created with the software R, both growth models were compared under different scenarios. The first part of this thesis examines the effect of different fisheries and their associated gear selectivity. Purse seine, baitboat and pelagic longline fisheries, which target yellowfin tuna in the Atlantic Ocean, were incorporated into the analysis. The second part looks at different sources of variability that occur either in nature (observation error) or in the process of analysis (process error). These include different growth variation, looking only at the fast growing young fish and using a set birth date versus a spawning period. These scenarios were used to determine if the sample, derived from a fishery-dependent sample, reflects the true population. Three populations of yellowfin tuna were created: an un-fished population, a fished population from stock assessment data, and a fished population from simulation software called ‘Population Simulator’. These populations were all analyzed for the different scenarios as well as the different fisheries. The final part of this thesis looks at three similar tuna species; skipjack (Katsuwonus pelamis), bigeye (Thunnus obesus ) and albacore (Thunnus alalunga). The same scenarios and gear selectivities were applied to these tuna species. The results of this study showed that the two-stanza growth curve was not a better fit for yellowfin tuna population in the Atlantic Ocean than the traditional von Bertalanffy growth curve. There were several scenarios that favored the two-stanza growth curve, but either it was a sample population not representative of the Atlantic Ocean population, or the two-stanza had no initial growth rate, making it the same as a traditional growth curve. Based on these results, it was evident that the traditional von Bertalanffy growth curve was the more accurate growth curve to use for yellowfin tuna in the Atlantic Ocean and it is recommended that this growth curve be used in the stock assessments going forward.

The instantaneous mortality rate (M) is an important parameter in elasmobranch management and conservation, but is difficult to estimate directly. Thus, indirect estimates based on relatively easily obtained life history parameters are commonly used. Many indirect methods incorporate one or more parameters from the von Bertalanffy growth model (VBGM), which is often criticized for its inability to describe changes in growth associated with maturity. The Lester growth model (LGM) is a biphasic alternative to the VBGM that incorporates trade-offs between reproduction, growth, and survival, and may therefore more accurately estimate M. I used published data from 29 elasmobranch species to compare the performance of the LGM to four conventional growth models and nine conventional methods for indirectly estimating M. For three species (Heterodontus portusjacksoni, Rhizoprionodon taylori, and Carcharhinus limbatus), I obtained direct estimates of M to evaluate the accuracy of indirect M methods. According to AICc, the LGM was the best fitting model for 80.8% of datasets. Using one-sample t-tests, I found that five indirect M methods (two of which are dependent on the LGM) consistently generated estimates of M that were in close agreement with direct estimates. The most common methods in elasmobranch literature appear to be overestimating M by factors of 1.34 – 1.91. However, further research is needed to verify these results across a wider range of species. Overall, I recommend using the LGM to describe the lifetime growth of sharks, and estimating M by averaging across five indirect methods.

Atualmente o Brasil é o quinto maior produtor de cacau no mundo e a sua produção está diretamente ligada ao ponto certo da colheita, colher frutos verdes ou verdoengos faz com que suas sementes tenham menor peso, em 1000 frutos maduros as amêndoas secas pesam em média 40 kg, colher frutos verdoengos, ou seja, frutos que estão parcialmente maduros, faz com que esse peso caia para 36 kg em média uma perda verificada de 10%, já quando os frutos estão verdes o peso passa a ser em média de 32 kg, possuindo uma perda de 20%, por isso é importante conhecer as fases de crescimento, que permite estabelecer formas adequadas de manejo, adubação e irrigação. Dentre as características biométricas do fruto do cacaueiro as que tem maior relevância econômica são o comprimento, o diâmetro e o volume. Uma forma de explicar relações de crescimento e produtividade de plantas, árvores, frutos ou animais é por meio da utilização de modelos de crescimento, pois possuem parâmetros com interpretação biológica. Os mais utilizados nestas áreas são os modelos: Logístico, Gompertz, Von Bertalanffy, Richards e Brody, sendo os dois últimos mais utilizados para descrever o crescimento animal. O objetivo do trabalho é avaliar a qualidade de ajuste e de predição dos modelos não lineares, Logístico, Gompertz e Von Bertalanffy, para medidas de comprimento e diâmetro do fruto do cacau, com a finalidade de predizer o seu volume. Para predizer o volume do fruto foi utilizado a fórmula de volume do esferoide prolato. Os critérios AIC e BIC foram utilizados para verificar qual dos modelos se ajusta melhor à essas medidas, já para verificar qual modelo se ajusta melhor na predição do volume do fruto, foram relacionadas as estatísticas: viés médio, índice de concordância, eficiência da modelagem e o desdobramento do quadrado médio do erro de predição. / Currently Brazil is the fifth largest producer of cocoa in the world and its production is directly linked to the right point of harvest, harvesting green or green fruits makes their seeds have less weight, in 1000 mature fruits dry almonds weight on average 40 kg, harvested green fruits, that is, fruits that are partially ripe, causes this weight to fall to 36 kg on average a verified loss of 10%, when the fruits are green the weight becomes an average of 32 kg, with a loss of 20%, so it is important to know the growth phases, which allows to establish appropriate forms of management, fertilization and irrigation. Among the biometric characteristics of the cacao fruit, the most economically important are length, diameter and volume. One way to explain growth and productivity relationships of plants, trees, fruits or animals is through the use of growth models, since they have parameters that with biological interpretation are the most used in these areas: Logistics, Gompertz, Von Bertalanffy, Richards and Brody, the last two being most used to describe animal growth. The objective of this work is to evaluate the quality of fit and prediction of the non linear models, Logistic, Gompertz and Von Bertalanffy, for measures of length and diameter of the fruit of the cocoa, in order to predict its volume. To predict the volume of the fruit, the volume formula of the prolate spheroid was used. The AIC and BIC criteria were used to verify which model best fits these measures, and to verify which model best fits the fruit volume prediction, the statistics were related: mean bias, concordance index, modeling efficiency, and the unfolding of the mean square of the prediction error.