abstract: Early hominins present an unusual pattern of sexual dimorphism. On one hand, the canine teeth of these species are weakly size-dimorphic, vertically short, and nonhoning, suggesting a social system characterized by infrequent, low-intensity intermale competition and monogamous pair-bonding. On the other hand, marked size variation in skeletal remains attributed to species of Australopithecus is thought to reflect strong body-mass dimorphism, which is more consistent with intense intermale competition. Reconciling these conflicting signals and understanding their adaptive significance is a major goal of paleoanthropology. This dissertation research contributes to this objective by investigating factors that may constrain or reduce canine height in extant anthropoid primates. Two hypotheses regarding the relationship between canine height and other elements of the masticatory system were tested using phylogenetic comparative methods. According to the first hypothesis, canine reduction is a pleiotropic by-product of changes in the sizes of other components of the dentition. With respect to canine height, the results of this study fail to support this idea. There is limited evidence for a relationship between basal canine crown dimensions and incisor and postcanine size, but significant interspecific correlations between these variables are not strong and are restricted primarily to the female maxillary dentition. These results indicate that if pleiotropy influences canine size, then its effects are weak. The second hypothesis proposes that canine reduction is a consequence of selection for increased jaw-muscle leverage. This hypothesis receives some support: there is a clear inverse relationship between canine height and the leverage of the masseter muscle in male anthropoids. Females do not exhibit this association due to the fact that dimorphism in muscle leverage is weak or absent in most anthropoid species; in other words, female muscle leverage tracks male muscle leverage, which is linked to canine height. Leverage of the temporalis muscle is not correlated with canine height in either sex. Two specimens of the 3.0-3.7-million-year-old hominin Australopithecus afarensis fall at or beyond the upper end of the great ape range of variation in masseter leverage, which is consistent with the idea that hominin canine evolution was influenced by selection for increased jaw-muscle leverage. / Dissertation/Thesis / Ph.D. Anthropology 2010

Les réseaux neuroendocrines qui contrôlent la reproduction sont mis en place pendant le développement sous l’action des stéroïdes sexuels endogènes. Toute perturbation de l’équilibre hormonal pendant ces phases critiques pourrait être à l’origine de troubles de la fonction de reproduction chez l’adulte. Ce travail vise à identifier l’impact d’une exposition développementale à un oestrogène de synthèse, l’éthinyloestradiol (EE2), sur les réseaux neuroendocrines et les conséquences physiologiques et comportementales chez l’adulte et sa descendance. Nos résultats ont montré que l’EE2 induit des perturbations des comportements sexuels chez les mâles et chez les femelles et une modification des réseaux hypothalamiques à GnRH et des neurones à calbindine qui contrôlent la physiologie et les comportements reproducteurs. Nous avons également montré que certains effets de l’EE2 sont transmis jusqu’à la quatrième génération, mettant ainsi en évidence le caractère transgénérationnel de ces perturbations. Ces résultats mettent en évidence la sensibilité des réseaux neuroendocrines aux perturbateurs endocriniens et la nécessité de prendre en compte ces paramètres dans l’évaluation de leurs effets sur la santé et la reproduction. / Neuroendocrine networks controlling reproductive function are established during development by the action of endogenous sex steroids. Any disturbance in the hormone balance during these critical phases may cause several disorders in reproductive function in adulthood. This work aims at identifing the consequences of a developmental exposure to the synthetic pharmaceutical estrogen ethinylestradiol (EE2) on the neuroendocrine and behavioral outcomes of the reproductive function in adult individuals and their offspring. Our findings showed that EE2 induced disturbances of sexual behaviors in males and females and modified the GnRH and the calbindin hypothalamic networks of exposed animals. We also showed that some effects of EE2 were transmitted up to the fourth generation, pointing out the transgenerational character of certain effects. All these results highlight the sensitivity of neuroendocrine networks to endocrine disruptors and the need to consider these parameters in assessing their effects on health and reproduction.

Le kisspeptine est un peptide, encodé par le gène Kiss1, qui joue un rôle majeur dans le contrôle central de la fonction de reproduction en régulant la sécrétion du GnRH après la naissance. Les neurones exprimant Kiss1 apparaissent avant la naissance exclusivement dans le noyau arqué. Les objectifs de cette thèse étaient de décrire comment le système s‟organise avant la naissance en fonction du sexe à une période où il existe chez le mâle un pic prénatal de testostérone, puis de déterminer si cette organisation pouvait être influencée par les stéroïdes sexuels. Nos résultats ont permis 1) de caractériser précisément chez la souris la mise en place des cellules kisspeptine en fonction du sexe et d‟identifier un gradient de différenciation antéro-postérieur sexe-indépendant 2) de mettre en évidence une interaction réciproque avec les neurones à GnRH, chez les mâles et les femelles, suggérant ainsi une certaine maturité du système 3) de montrer la diversité des récepteurs aux stéroïdes sexuels déjà exprimés par ces cellules avant la naissance ainsi que l‟émergence d‟un dimorphisme sexuel 4) de démontrer la sensibilité et la réponse morphologique à l'oestradiol de ces cellules in vitro après la mise au point du premier modèle de culture primaire de cellules kisspeptine. / Kisspeptin neurons express the Kiss1 gene encoding kisspeptin, a potent neuropeptide secretagogue of gonadotropin releasing hormone (GnRH) that plays a fundamental role in regulation of reproductive life cycles after birth. Neurons expressing Kiss1 appear before birth only in the arcuate nucleus. The overall purpose of this study is to understand how kisspeptin neurons are set up during fetal development, if and how estrogen signaling in these cells could interfere with their development at a time of a prenatal testosterone peak in male. Our finding showed 1) precisely the placement of kisspeptin cells as a function of sex and to identify a sex-independent anteroposterior differentiation gradient 2) a reciprocal interaction with GnRH neurons, in males and females, thus suggesting a certain maturity of the system 3) the diversity of sexual steroids receptors already expressed by these cells before birth as well as the emergence of a sexual dimorphism 4) sensitivity and morphological response to estradiol of these cells in vitro after the development of the first primary culture model of kisspeptin cells.

Dentre todas as famílias de Characiformes, Characidae, com 1209 espécies válidas é, sem dúvida, a mais problemática, com suas relações intra e inerfamiliares em Characiformes ainda pouco definidas. Isto se deve à imensa diversidade e variação morfológica presente em seus representantes. Embora alguns trabalhos, tanto morfológicos quanto moleculares, incluindo um grande número de táxons terminais tenham sido realizados, as relações intra e interfamiliares continuam controversas. Estes trabalhos, no entanto corroboram o monofiletismo de um grupo caracterizado pela ausência do osso supra-orbital, um caráter aparentemente redutivo: clado 204 de Mirande, 2010, Clado 37 de Oliveira et al.,2011, Clado A de Malabarba & Weitzman, 2003 semelhante ao ortí clade proposto em Ortí & Meyer, 1997. Diversos autores resumiram as principais dificuldades enfrentadas por ictiólogos no estudo de relações intra e interfamiliares em Characidae: 1) grande diversidade aliada à relativa pouca divergência morfológica, 2) redução em tamanho, com consequente perda/truncamento de muitas estruturas por pedomorfose, 3) falta de boas séries de exemplares bem preservados e sexualmente desenvolvidos em coleções, e 4) necessidade de mais informação quanto ao colorido em vida e dimorfismo sexual. O dimorfismo sexual tem sido estudado extensivamente em Characidae, se mostrando informativo na resolução de grupos em níveis menos inclusivos, como Glandulocaudinae sensu Weitzman & Menezes (1998) e Xenurobryconini. Embora tenha havido um notável avanço no conhecimento dos caracteres sexuais secundários em Characidae, nota-se que grande parte dos estudos se restringem aos táxons com caracteres sexuais secundários mais evidentes, mais especializados e em grupos muito pouco inclusivos. Nesta contribuição realizamos uma análise anatômica comparada incluindo um grande número de espécies, representando todos os grupos menos inclusivos citados em literatura na tentativa de encontrar padrões que reflitam a evolução dos grupos menos inclusivos. Como resultado, desvendamos uma diversidade incrível nestes caracteres, que se mostraram potencialmente informativos na resolução de relações de grupos menos inclusivos em Characidae. / Among all Characiforms families, Characidae, with 1209 valid species is, undoubtedly, the most problematic, with its relationships within Characiformes still poorly defined. This is due to the great diversity and morphological variation among its members. Although some recent studies, both morphological and molecular including a great number of terminal taxa were performed, its intra and inter-family relations are still very controversial. These studies however, corroborate the monophyly of a group characterized by the absence of supra-orbital bone, a seemingly reductive character: Clade 204 of Mirande, 2010, Clade 37 of Oliveira et al., 2011, Clade A of Malabarba & Weitzman, 2003 similar to the Ortí clade proposed in Ortí & Meyer, 1997. As summarized by many authors in literature the main difficulties faced by ichthyologists in the study of intra and inter-familial relationships in Characidae: 1) diversity combined with relatively little morphological divergence, 2) reduction in size with consequent loss/truncation of many structure by paedomorphosis, 3) lack of good series of well-preserved sexually developed specimens into collections, and 4) the need form more information about the of color in life and sexual dimorphism. The sexual dimorphism has been studied extensively in Characidae, being very informative on the resolution of less inclusive groups, as Glandulocaudinae sensu Weitzman & Menezes (1998) and Xenurobryconini. Although there has been a remarkable advance in the knowledge os secondary sexual character in Characidae, it is clear that most of the studies are restricted to taxa with secondary sexual characters more evident, more specialized and on very less inclusive groups. In this contribution we performed an anatomical comparative analysis including a large number of species, representing all less inclusive groups cited in literature in attempt to find which patterns reflect the evolution of the less inclusive groups within the family. As a result, we unveil an incredible diversity in these characters, which might be potentially informative in resolving relations less inclusive groups in Characidae.

Sex estimation in bioarchaeological research is paramount for comparative analyses of skeletal remains and developing estimates of other demographic variables. Frequently, sex is estimated utilizing the morphology of pelvic and cranial bones in archaeological skeletal samples. Regrettably, these bones are often damaged, destroyed, or lost and cannot be employed for the estimation of sex. Fortunately, a variety of metric and visual sex estimation methods have been developed on modern skeletal samples with known demography. Disappointingly, due to the population specific nature of many of these metric methods, they cannot be accurately applied directly to alternate skeletal samples. However, these methods can be redeveloped and retested for archaeological skeletal samples if the proper protocol is utilized. This research utilizes the protocol for developing methods of sex estimation on samples with unknown sex developed by Murail et al. (1999). Utilizing select hand and foot bones from four prehistoric Native American skeletal samples from Alabama and Illinois, multiple discriminant functions were developed and tested on both Archaic and Mississippian Period skeletal samples. Furthermore, the four individual site samples were combined into two geographical and two temporal samples, as well as an all pooled sample in order to test the broader applicability of these methods. The results indicate that sex estimation methods can be developed on samples where sex is not known. Additionally, the discriminant functions developed produce high levels of classification for the sites, individually, as well as for the geographic, temporal, and all pooled samples. The latter suggests these functions have broader applicability for these regions and temporal periods. Moreover, the concordance rates for these functions are similar to the accuracy rates when these bones were applied to samples with known sex.

In the past few decades, an area of skeletal research focusing on shape analyses has gained popularity in the field of physical anthropology, and subsequently forensic anthropology. Known as geometric morphometrics, this type of analysis allows the researcher to place the morphological shape of bones into a statistical framework to answer questions on a variety of topics, including sexual dimorphism. Sex assessment from the long bones has been traditionally conducted using traditional morphometric methods (Iscan and Miller-Shaivitz 1984; Steyn and Iscan 1997), and as a result, relies mainly on size differences and has not considered how joint morphology and shape affect sex. For this project, a geometric morphometric analysis of the proximal tibia in a modern Caucasian American population was conducted using a sample of 100 male and 100 female tibiae from the William M. Bass Donated Skeletal Collection at the University of Tennessee at Knoxville. The proximal tibia's effectiveness as an indicator of sex in a modern American population was evaluated via generalized Procrustes, principal components, and discriminant function analyses. Principal components revealed a lack of separation between males and females in terms of proximal tibia shape. The discriminant function analysis was successful at discriminating males from females, but cross-validation yielded a low total accuracy rate of 58%. The shape of the proximal tibia contributes to sexual dimorphism in a Caucasian American population, but is only slightly useful in a discriminant function. Further research should be conducted on different populations and using different skeletal landmarks.

This project analyzes the sexual dimorphism of the femur and tibia using geometric morphometrics. The study sample includes 250 individuals of known sex and age at death with complete, non-damaged, non-pathological skeletal remains from the William M. Bass Donated Skeletal Collection at the University of Tennessee, Knoxville. Ages range from 19-96 for males (mean=56.92 years) and 29-97 for females (mean=59.48 years). A combination of landmarks and semi-landmarks were collected on the proximal and distal epiphyses of each bone using a Microscribe, which helps capture the overall size and shape variation present in the sample. Only individuals from one population, White, where analyzed in order to eliminate population variation bias. Classification rates for males and females for the proximal femur were 80.8% and 78.4% respectively, for the distal femur 92.6% and 89.6% respectively, for the proximal tibia 80.8% and 83.2% respectively, and the distal tibia 81.6% and 80.8% respectively, all with a p<0.0001. These rates created a classification model for which epiphysis gave the most accurate assessment of sex: the distal femur, followed by the proximal tibia, then the distal tibia, and lastly the proximal femur. This study indicates the knee joint is the most dimorphic, followed by the ankle and then the hip. The results fall in line with another study indicating the knee is more sexually dimorphic in a modern White population (Spradley and Jantz 2011), though in contrast to their results this study found the distal femur was more dimorphic than the proximal tibia. This method indicates that in comparison to standard measurements, geometric morphometrics may provide a more reliable method for sex estimation when used, specifically on the knee. Certain landmarks were then selected based on the standard taphonomic process of coffin wear and postmortem damage (Pokines and Baker 2014) for exclusion to determine the usability of the method on fragmented or damaged skeletal remains. When combinations of landmarks were removed, the distal femur still possessed the highest classification rates with over 80% accuracy.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O dimorfismo sexual exibido por machos polifênicos em algumas espécies do gênero Ptychoderes envolve variação no rostro, antena e ventritos. A existência de polifenismo pode ser um importante componente no processo evolutivo por meio de novidades morfológicas e comportamentais. O objetivo desse estudo foi determinar a variação em caracteres morfométricos, polifenismo em machos, variação de estruturas com conhecido dimorfismo sexual, possíveis padrões alométricos e testar estas inferências para Ptychoderes através do mapeamento do dimorfismo sexual e de machos em uma reconstrução filogenética de Ptychoderes usando Mesquite 2.04. Foram medidas 23 variáveis morfométricas em 510 espécimes com as seguintes análises realizadas: análises de cluster, analises de componentes principais (PCA), analise de variáveis canônicas (AVC), análise de regressão por eixo maior reduzido (RMA). Cada tipo de dimorfismo foi mapeado em uma filogenia prévia como dois estados separados usando parcimônia. Para todas as espécies o dimorfismo sexual apresentou diferenças significativas entre os sexos com relação aos segmentos antenais (II- X).O compriemtno do rosto e ventrito V foram confirmados como indicativos de dimorfismo sexual (exceto em P. jordani). A única espécie em que não ocorreu machos polifenicos foi P. depressus. Nas outras espécies machos grandes e pequenos diferem significantemente para muitas variáveis com similaridades e diferenças. Na ACP, o primeiro componente (PC1) apresentou alta porcentagem de variância nos dados de todas as espécies; apresentou loadings de mesmo sinal sugerindo diferenças relacionadas ao tamanho para as espécies P. jordani, P. depressus, P. virgatus, P. mixtus e P. callosus e para as espécies P. viridanus, P. antiquus, P. elongates e P. nebulosus apresentou loadings positivos e negativos sugerindo diferenças relacionadas a forma (alometria). O PC2 apresentou loadings positivos e negativos para todas as espécies, um provável componente alométricos. A AVC confirmou os grupos: machos grandes, machos pequenos e fêmeas quando estes ocorreram. Nós encontramos diferentes padrões alométricos para todas as espécies com diferenças e semelhanças entre as espécies. Todos esses resultados confirmam a hipótese de polifenismo em machos e dimorfismo sexual para Ptychhoderes. A análise dos padrões alométricos para o dimorfismo sexual revelou alometria positiva para o comprimento do rostro (CR1) em machos e fêmeas, com os ventritos apenas em machos. Padrões alométricos positivos relacionados ao polifenismo nos antenômeros foram confirmados para os machos grandes e pequenos de quase todas as espécies exceto em P. nebulosus. O ancestral de clados na filogenia de Ptychoderes foi inferido para machos polifênicos (exceto P. depressus) com variáveis no rostro, antenas e ventritos indicativas de dimorfismo sexual com alometria positiva. Estes padrões poderiam estar ligados com o comportamento de proteção das fêemeas realizados por machos grandes durante a oviposição. / The sexual dimorphism exhibited by polyphenic males in some species of the Ptychoderes involves variation in rostrum, antennae and ventrites. The existence of polyphenism should be an important component in the evolutionary process via morphological and behavior novelties. The goal of this study was to determine the variation of monomorphic traits, polyphenism in males, variation of structures with known sexual dimorphism, possible allometric patterns and to test these predictions for Ptychoderes by mapping both male and sexual dimorphism in a phylogenetic reconstruction of the genus Ptychoderes using Mesquite 2.04. Twenty-three morphometric variables were measured in 510 specimens with the following analyses performed: Cluster analysis; Principal Component Analysis (PCA); Canonical Variance Analysis (CVA), analysis of regression of Reduced Major Axis (RMA). Each type of dimorphism was mapped on the previous phylogeny as a separate two-state using parsimony. For all species the sexual dimorphism provided significant differences between the sexes for antennal segments (II-X). The length of rostrum and ventrite V were confirmed as indication of sexual dimorphism (except P. jordani). The unique species without polyphenics males was P. depressus. The others species major and minor males differed significantly for many variables with similarities and differences. In the PCA, the first component (PC1) had a high percentage of the variance in the data for all species; present loadings of the same signal suggesting differences related to the size of the species P. jordani, P. depressus, P. virgatus, P. mixtus and P. callosus and for the species P. viridanus, P. antiquus, P. elongates and P. nebulosus the PC1 presented positive and negative loadings suggesting differences related to the shape (allometry). The PC2 showed both positive and negative loadings for all species, a probable allometric component. The CVA confirmed the groups: major males, minor males and female, when they occurred. We found different allometric patterns for all species, with similarities and differences between species. All these results confirm the hypothesis the polyphenism in males and sexual dimorphism for Ptychoderes. The analyses of allometric patterns for sexual dimorphism results positive allometry for rostral length (RL1) in males and females, with ventrites only for males. The positive allometric patterns related with polyphenism in the antennae were confirmed for larges and small males in almost all species, except in P. nebulosus. The ancestor of the clades in the Ptychoderes phylogeny was predicted to have polyphenic males (except P. depressus) with variables in the rostrum, antennae and ventrites indicative of the sexual dimorphism with positive allometry. These patterns should be linkage to the protection behavior of the female performed by large males during oviposition.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study involved two experiments that addressed mate choice, male competition for mature females and the communication pathways used by both sexes in Aegla longirostri. In the first experiment, males were paired according to body and cheliped size, and they were acclimated in the laboratory for a week. Next, they were accommodated in opposite sides of an aquarium that was divided in three parts. A container with a female inside was inserted in the center of the aquarium, according to four treatments: Fimat, perforated and translucent container holding an immature female (N = 10); FmatCV, the same container holding a mature female (N = 10); FmatV, translucent and non-perforated container holding a mature female, (N = 10); FmatC, perforated opaque container with a mature female (N = 10); NF = no female in the container. Afterwards, the males were released and left interacting for 20 min. The following variables were quantified: time of the first three bouts, time spent in aggressive acts, latency period, time that animals remained near the container and the number of antennal whips per bout second. Thus, we observed that males fight more quickly and less intensely in the presence of mature females, independently of the communication pathway used. However, both stimuli were needed to elicit a guarding behavior by the winner. Therefore, the female might be controlling the cues that advertise her receptivity, only releasing them when the preferred male is near. This causes information asymmetry between the males, which makes shorter fights. We also demonstrated the importance of bimodal stimuli (chemical + visual) for reproductive behaviors, since the behavioral repertory presented was more complex when both could be used. To assess mate choice in A. longirostri, we used a different experimental design. Animals were grouped in triads, two of them were used as choices ( targets ) and one as the choosing individual ( focal ). They were accommodated in a Y-maze in four different treatments: MD, adult male as focal animal and two females, one immature and one mature as targets (N = 8); FD, mature female as focal animal and two adult males, a large male and a smaller one as targets (N = 7); Q, like FD but the female could choose based only in chemical cues provided by the targets (N = 7); F, like FD but the female could choose based only in visual cues (N = 7). The eglids were acclimated for 10 min and then the focal animal was released for 20 min. We quantified the time spent in the corridor as an index of preference. Males did not choose between females, however the time spent in the mature female corridor was highly variable. On the other hand, the females only chose the large males when they could assess them through visual and chemical stimuli. Thus, females may control the release of cues that advertise her receptivity, and so, only preferred males could actually make the choice. The females may also need more information to choose between potential mates, since they only showed preference when two stimuli were present. / Este estudo envolveu dois experimentos que abordaram a escolha de parceiros, a competição por fêmeas maduras e os meios de comunicação utilizados pelos indivíduos de Aegla longirostri. No primeiro, machos desta espécie foram pareados conforme o tamanho corporal e dos quelípodos e, após uma semana de aclimatação em laboratório, foram acomodados em lados opostos de um aquário dividido em três partes. No centro deste aquário foi inserido um recipiente que continha uma fêmea, conforme quatro tratamentos: Fimat, recipiente translúcido e perfurado que continha uma fêmea imatura (N = 10); FmatCV, igual ao anterior, porém com uma fêmea madura (N = 10); FmatV, recipiente sem perfurações, translúcido e com fêmea madura (N = 10); FmatC, recipiente perfurado, opaco e com fêmea madura (N = 10); NF = sem fêmea, recipiente vazio (N = 5). Então, os machos eram liberados e deixados para interagir por 20 min. Foram quantificados: o tempo dos três primeiros confrontos, tempo que os animais passaram em atos agressivos, tempo de latência, tempo que permaneceram próximos ao recipiente e o número de antenadas dividido pelo tempo de confronto. Com isso, foi observado que os machos possuem embates mais rápidos e menos intensos na presença de fêmeas maduras, independente do meio de comunicação. Porém, foram necessários ambos os estímulos para que o macho vencedor ficasse mais tempo próximo do recipiente, em um comportamento possivelmente de guarda. Logo, a fêmea pode estar controlando o estímulo que anuncia sua receptividade, liberando-o apenas quando o macho preferido está próximo, o que causa assimetria de informações entre os combatentes, fazendo com que o confronto termine mais cedo. Também foi demonstrada a importância de estímulos bimodais (químico + visual) para comportamentos reprodutivos, uma vez que na presença destes, o repertório apresentado foi mais complexo. Para verificar a escolha de parceiro pelos sexos de A. longirostri, foi utilizado outro design experimental que foi composto de três animais, sendo dois para serem escolhidos ( alvos ) e um para escolher ( discriminante ), dispostos em um aquário em Y, em quatro tratamentos: MD, macho adulto como animal discriminante e duas fêmeas, uma imatura e outra madura, como alvos (N = 8); FD, fêmea madura como discriminante e dois machos adultos, um grande e outro pequeno, como alvos (N = 7); Q, igual ao anterior, porém a fêmea poderia escolher baseada apenas em estímulos químicos dos alvos (N = 7); V, igual ao FD, porém a fêmea poderia escolher utilizando apenas os estímulos visuais dos alvos (N = 7). Os eglídeos eram aclimatados por 10 min e, após, o animal discriminante era liberado por 20 min; o tempo que este permanecia em cada corredor era quantificado e utilizado como índice de escolha. Os machos não realizaram escolha, porém houve muita variação de tempo permanecido no corredor que havia fêmea madura. Já as fêmeas só escolheram machos grandes quando este poderia liberar estímulos visuais e químicos concomitantemente. Portanto, a fêmea provavelmente controla a liberação dos químicos que indicam sua receptividade, por isso só alguns machos realizaram a escolha. Elas também necessitam de mais informações para escolher um parceiro, uma vez que só realizaram escolha quando havia dois estímulos presentes.

Made available in DSpace on 2014-06-11T19:22:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T20:29:26Z : No. of bitstreams: 1 barros_va_me_sjrp.pdf: 10427636 bytes, checksum: 5bc34f35bd7667802f502c2a426cc25c (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dados sobre a biologia reprodutiva (e.g. ciclos reprodutivos, maturação e dimorfismo sexual, padrões de estocagem de esperma e padrões de atividade) de três espécies de serpentes da Família Viperidae da região neotropical, Crotalus durissus (N = 228), Bothrops leucurus (N = 320) e Bothrops erythromelas (N = 239), são apresentados neste estudo. Os machos atingem a maturidade sexual com comprimento rostro-cloacal (CRC) menor que as fêmeas em B. erythromelas e B. leucurus. Nas populações de C. durissus da região Nordeste do Brasil, machos e fêmeas atingem a maturidade sexual com comprimentos semelhantes, porém há relatos de padrões diferentes para outras populações. Não há diferença quanto ao CRC de machos e fêmeas sexualmente maduros de C. durissus e B. leucurus, espécies paras as quais há relato de combate entre os machos. Fêmeas de B. erythromelas são maiores que os machos, característica esperada para uma espécie em que não há a ocorrência de combate. Os ciclos reprodutivos de machos e fêmeas das três espécies, descritos com base em análises morfológicas e histológicas das gônadas e vias genitais, são sazonais e influenciados tanto pelas condições climáticas quanto pelas relações filogenéticas. O período de vitelogênese ocorre ao longo de grande parte do ano em B. leucurus e B. erythromelas e em um período mais restrito em C. durissus, durante o outono e a primavera. Relatos de acasalamento durante o outono estão disponíveis para as três espécies, embora para B. leucurus o acasalamento também possa ocorrer durante o inverno. Em B. leucurus e C. durissus, após a cópula, os espermatozóides permanecem estocados no trato reprodutivo da fêmea, no interior da contração muscular uterina, até o momento da ovulação e fertilização (final do inverno - início do verão). É provável que as fêmeas de B. erythromelas também... / New data about reproductive biology (e.g. reproductive cycles, sexual maturation and dimorphism, sperm storage and activity patterns) of three species of Viperidae snakes from the Neotropical region, Crotalus durissus (N = 228), Bothrops leucurus (N = 320) and Bothrops erythromelas (N = 239), are presented. B. erythromelas and B. leucurus males attain sexual maturity at smaller sizes (snout-vent length – SVL) than conspecific females. C. durissus males and females from northeastern Brazil attain sexual maturity at similar sizes. However, other sexual maturity patterns have already been described for other populations. No significant difference was observed on SVL between mature males and females of C. durissus and B. leucurus. Male-male combat behavior has been previously described for these species. B. erythromelas females are larger than males and male-male combat has never been reported for this species. Reproductive cycles are described considering morphological and histological analysis of the gonads and genital ducts. Reproductive cycles of the three species considered herein are seasonal and influenced by climatic conditions and phylogenetic relationships. Secondary vitellogenic follicles may be found in every season in B. leucurus and B. erythromelas, and only during autumn and spring in C. durissus. Records of mating during the autumn are available for the three studied species, but it may also occur during winter in B. leucurus. After mating, spermatozoa are stored in the female reproductive tract by means of an uterine muscular twisting (UMT) until ovulation and fertilization occur (end of winter – beginning of summer) in C. durissus and B. leucurus. It is probable that it also occurs in B. erythromelas because mating and ovulation are not synchronous in this species either. However, we did not find evidences for the occurrence of the UMT to confirm... (Complete abstract click electronic access below)