Comportamento alimentar do camarão marinho farfantenaeus subtilis em condições laboratoriais

Shrimp culture represents an important activity to brazilian economy. The northeastern region has presented high levels of production because of its climatic conditions. An important factor for the activity´s major development is related to the introduction of the species Litopenaeus vannamei. The use of an exotic species can disturb the ecosystem. In the last decades, L. vannamei has been the only species cultivated in Brazilian farms, there not being an alternative species for shrimp culture. So, there is an urgent need to developing new studies with the native species, which might represent an alternative concerning shrimp production, with emphasis on Farfantepenaeus subtilis. Another important aspect related to the activity is feeding management, once it is quite usual that feed offer on the pond does not take into account either the species´ physiology and behavior or the influence of environmental variables, such as light cycle and substrate. That knowledge may optimize management and so reduce the impact of effluents in the environment. This study´s objective was characterizing feeding behavior of F. subtilis in laboratory. For that, an ethogram was developed, using 20 wild animals which were observed through ad libitum and all occurrences methods. Two experiments were developed in order to register feeding behavior on different substrates, along 15 days, each. In the first experiment, 40 animals were distributed in eight aquaria, half being observed during the light phase of the 24 hour cycle and the other half in the dark phase, both in halimeda substrate. In the second experiment, 20 animals were distributed in four aquaria, under similar conditions as the previous ones, but in sand substrate. In both experiments, animals were observed respectively one, four, seven and ten hours after the beginning of the phase, for light phase, for the dark phase, in ten minute observation windows, before and immediately after feed offer. The following behaviors were registered: feed ingestion, ingestion of other items, inactivity, exploration, vertical exploration, swimming, crawling, digging, burrowing, and moving by the animals. Observation windows after feed offer also included latency to reach the tray and to ingest feed. Nineteen behaviors were described for the species. F. subtilis presented more behavioral activities in halimeda substrate even in the light phase, while burrowing was predominant in sand substrate. In both substrates, moving, crawling and exploration were more frequent after feed offer, but inactivity and burrowing were more frequent before that. Feed ingestion was more frequent in halimeda, both in light and dark phases. Weight gain was also more prominent in that substrate. In sand substrtate, ingestion was more frequent in the dark phase, which suggests that higher granulometry facilitates feed ingestion in F. subtilis juveniles. Our results demonstrate the importance of studies for the better knowledge of the species, specially its response to environmental stimuli, in order to improve animal management

O efeito inimigo íntimo é aplicável a Dinoponera quadríceps (Hymenoptera, Formicidae)?

Food access, territory or reproductive partner can generate conflicts between individuals in many species with occurrence of aggressive behaviors. However some species respond less aggressively to intrusion by neighbors than non-neighbors in its territory to minimize the costs of continuous fight. This difference in aggression is called Dear Enemy Effect described in various vertebrates and invertebrates. To investigate if this phenomenon occurs in Dinoponera quadriceps (Hymenopetra, Formicidae) three colonies, two neighbors and one non-neighbor, were captured in its natural environment then transfered to the laboratory where we did experimental confrontation intra and inter colonies involving one pair of workers. We compared the behavioral frequency exhibited by each worker, the intensity and duration of the confrontation between a neighbor and a non-neighbor referring the place where they were collected. Our results revealed that Dear Enemy Effect does not apply to D. quadriceps due aggressive response is more intense and longest toward neighbor than non-neighbor, probably due intra specific competition, ecological factors and characteristic of the species

A trapaça é rara, mas é bem lembrada: o efeito da cor da pele e do gênero na memória de faces

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

O efeito da dessincronização circadiana sobre o metabolismo

The lost of phase relationship between rhythms and behaviour can, and often do, undesirable consequences. The purpose os study was to ascertain the effect of circadian desynchronization in T22 about metabolism of wistar rats. The subjects consisted of 24 animals separated in two groups: control (n=12) T24 with 8 weeks of aged and experimental group (n=12) T22, also with 8 weeks of aged. Both the groups were subject to register of locomotor actitivity, body temperature, body weight and food intake in all the experiment. And more, both the groups were subject to food deprivation, running in treadmill and forced swimming. The results show rhythm of locomotor activity and body temperature desynchronized. Dont exist diference in body weight between both the groups (T24 = 386,75±40,78g e T22 380,83±44,28g) . However, the food intake was different between the phases, light and dark, in intergroup and intragroup. The body temperature was not different in food deprivation. The same ocurred for running in treadmill and forced swimming. Since similar alterations occur in shift workers, it is proposed that the experimental paradigm presented in this manuscript is a useful model of shift work. That is, alterations in activity/rest cycles and consummatory behavior can affect the health of organism

Fatores que influenciam a neofobia alimentar em fêmeas e filhotes de sagüis (Callithrix jacchus)

Considering the constant environmental changes, the ability to introduce new food items in the diet is crucial to omnivore animal survival. For optimal nourishment and lessening of intoxication risks, the animals must detect signs that indicate which items are adequate for their intake. We investigate some factors that interfere in the responses to non familiar food, modulating their neophobic behavior, of marmosets Callithrix jacchus, an omnivore and generalist primate, native to Northeast Brazil, known for being cautious in ingesting not known food. We analyzed the influence of food taste (sweet or salty), pregnancy and sex in feeding behavior and neophobic responses in these animals. 10 captive females were first selected, 5 of them being then pregnant. The females, pregnant or not, ate more when presented to the sweet items than to the salty ones. Pregnant females, however, themselves were less neophobic to both tastes, being also strongly neophilic to the sweets. We verified then the influence of nourishment during pregnancy on young males and females post natal feeding behavior. We observed 10 young divided in two groups, one whose mother ate that food item during pregnancy and one whose mother had no contact to it. In the first group that food was more easily accepted by the young, suggesting that neofobia and feeding behavior had a pre natal influence. Female young also ingested more food and were less neophobic than males, a difference already observed in behavior of adults of these specie. These results suggest that the low neophobic behavior to sweet food showed by females can be adaptive, and might have bestowed more fitness to those who presented it

Influência do ciclo estral no efeito do diazepam na ansiedade e memória de ratas

Memory and anxiety are related phenomena. Several evidences suggest that anxiety is fundamental for learnining and may facilitate or impair the memory formation process depending of the context. The majority of animal studies of anxiety and fear use only males as experimental subjects, while studies with females are rare in the literature. However, the prevalence in phobic and anxiety disorders is greater in women than in men. Moreover, it is known that gender maybe influence benzodiazepine effects, the classic drugs used for anxiety disorders treatment. In this respect, to further investigate if fear/anxiety aspects related to learning in female subjects would contribute to the study of phobic and anxiety disorders and their relationship with learning/memory processes, the present work investigates (a) the effects of benzodiazepine diazepam on female rats performance in a aversive memory task that assess concomitantly anxiety/emotionality, as the interaction between both; (b) the influence of estrous cycle phases of female rats on diazepam effects at aversive memory and anxiety/emotionality, and the interaction between both and (c) the role of hormonal fluctuations during estrous cycle phases in absence of diazepam effects in proestrus, because female rats in this phase received or not mifepristone, the antagonist of progesterone receptor, previously to the diazepam treatment. For this purpose, the plus maze discriminative avoidance task, previously validated for studies of anxiety concomitantly to learning/memory, was used. The apparatus employed is an adaptation of a conventional plus maze, with two opens arms and two closed arms, one of which presenting aversive stimulation (noise and light). The parameters used were: time in non-aversive arm compared to time in aversive and percentage of time in aversive arm on several temporal divisions, in order to evaluate memory; percentage of time in open arms, risk assessment, head dipping and end exploring to evaluate anxiety ; and distance traveled for locomotion. In experiment I, we found anxiolytic effect of diazepam only for 4 mg/kg dose, however the amnestic effect appear at a dose of 2 mg/kg. In second experiment, rats were divided in groups according estrous cycle phase (metaestrus/diestrus, proestrus e estrus). In this experiment, when we considered estrous cycle phase or diazepam treatment, the results did not demonstrate any differences in anxiety/emotionality parameters. The amnestic effects of diazepam occur in female rats in metestrus/diestrus and estrus and is absent in proestrous rats. Proestrous female rats that received mifepristone exhibited the amnestic effect of diazepam and also anxiolytic effects, that it was not previously observed in this dose. The results have demonstrated dissociation of anxiolytic and amnestic diazepam effects, not previously observed in males; the absence of amnestic effect of diazepam in proestrous phase; and the possible role of progesterone in aversive memory over diazepam effect, because the mifepristone, associated with diazepam, caused amnestic effect in proestrus

Disfunção sexual feminina e níveis dos hormônios esteroidais em mulheres obesas atendidas no ambulatório de cirurgia bariátrica do hospital universitário Onofre Lopes em Natal/RN

A disfunção sexual corresponde a alterações em uma ou mais fases da resposta sexual humana e apresenta maior prevalência na população feminina. Ademais, a participação de alguns fatores como obesidade e níveis dos hormônios esteroidais na disfunção sexual feminina (DSF) permanece incerta. O presente estudo deteve-se na análise da ocorrência de DSF numa população de mulheres portadoras de obesidade, cadastradas no Ambulatório de Cirurgia Bariátrica do Hospital Universitário Onofre Lopes, da Universidade Federal do Rio Grande do Norte, no município de Natal, RN. O estudo foi realizado em uma amostra composta por trinta e uma mulheres, com idade entre 20 e 50 anos, com índice de massa corpórea (IMC) > 30 Kg/m2. A todas as pacientes foi aplicado um questionário composto por uma seção com dados socio-econômicos, e outra abordando a saúde sexual feminina, sendo esta última correspondente ao Female Sexual Function Index (FSFI), para diagnóstico de DSF. A partir dessa caracterização, as pacientes foram reunidas nos grupos CD (pacientes com disfunção, n= 9) e SD (sem disfunção, n= 22). Para a análise do efeito da obesidade na DSF, as pacientes foram reunidas nos grupos 1 (6 pacientes com IMC grau I e II: entre 30 e 40 Kg/m2) e 2 (25 com IMC grau III: acima de 40). Para o estudo da participação dos hormônios esteroidais foram determinadas as concentrações séricas de cortisol, estradiol e dehidroepiandrosterona (DHEA) pelo método de quimiluminescência. A análise estatística dos dados foi realizada usando os testes ANOVA, MANOVA (Pillai), além de análise de Cluster. Para identificar as diferenças entre os domínios do FSFI, foi usado o teste T de Student. A significância considerada para todos os testes foi para p< 0,01. Das pacientes estudadas, 25,8% apresentaram DSF de acordo com o escore total do FSFI. A análise estatística posterior evidenciou que as diferenças ocorreram para os domínios desejo, excitação e orgasmo. Não foi encontrada relação da presença de DSF com os diferentes graus de obesidade ou com os níveis hormonais dos esteróides cortisol, estradiol ou DHEA. Contudo, foi encontrado aumento significativo nos níveis séricos de estradiol para o grupo 1, que corresponde ao de menor índice de IMC. Estes resultados mostram que a prevalência de DSF não diferiu entre os graus I,II e III de obesidade das pacientes deste estudo mas, quando presente, a disfunção ocorre nos domínios desejo, excitação e orgasmo. A maior concentração de estradiol encontrada nas pacientes de menor índice de IMC sugere uma possível relação entre as duas variáveis que precisa ser investigada em estudos futuros.

Detecção de predadores por dicromatas e tricromatas humanos e a sua implicação na evolução da visão de cores em primatas

Among placental mammals, primates are the only ones to present trichromatic color vision. However, the distribution of trichromacy among primates is not homogeneous: Old World primates shows an uniform trichromacy (with all individuals being trichromats) and New World primates exhibit a color vision polymorphism (with dichromatic males and dichromatic or trichromatic females). Visual ecology studies have investigated which selective pressures may have been responsible for the evolution of trichromacy in primates, diverging from the dichromat standard found in other mammals. Cues associated with foraging and the socio-reproductive status were analyzed, indicating a trichromatic advantage for the rapid detection of visually conspicuous objects against a green background. However, dichromats are characterized by an efficient capture of cryptic and camouflaged stimuli. These advantages regarding phenotype may be responsible for the maintenance of the visual polymorphism in New World primates and for the high incidence of color blindness in humans (standing around 8% in Caucasian men). An important factor that has not yet been experimentally taken into account is the predation risk and its effect on the evolution of trichromacy in primates. To answer this question, we prepared and edited pictures of animals with different coats: oncillas (Leopardus spp.), puma (Puma concolor) and ferret (Galictis cuja). The specimens were taxidermized and the photographs were taken in three different vegetation scenarios (dense forest, cerrado and grassland). The images of the predators were manipulated so that they fit into two categories of stimulus size (small or large). After color calibration and photo editing, these were presented to 40 humans (20 dichromats and 20 trichromats) by a computer program, which presented a set of four photos at a time (one picture containing the taxidermized animal amid the background vegetation and three depicting only the background vegetation) and recorded the response latency and success rate of the subjects. The results show a trichromatic advantage in detecting potential predators. The predator detection was influenced by the background, the predator species, the dimension of the stimulus and the observer s visual phenotype. As humans have a high rate of dyschromatopsias, when compared to wild Catarrhini or human tribal populations, it is possible that the increased rate of dichromats is a result of reduced pressure for rapid predator detection. Since our species came to live in more cohesive groups and resistant to attack by predators, with the advent of agriculture and the formation of villages, it is possible that the lower risk of predation has reduced the selection in favor of trichromats

Atividade de morcegos insetívoros (mammalia, chiroptera) no pampa brasileiro: uso de hábitat e sazonalidade

Bats correspond to 20% of the extant mammal species and, with a few exceptions, use echolocation, a spacial orientation system based on emission and analysis of echoes from sound waves, generally ultrasounds. Echolocation was discovered in the 1940 s and since the 1970 s ultrasound detectors have been commercially available, allowing the investigation of several aspects of the natural history and ecology of bats. Passive acoustic monitoring has been frequently used in habitat use studies, predominantly in North America and Europe, by comparing the number of bat passes between different habitat types. This dissertation presents the first evaluation of the spacial and seasonal variation patterns in the activity of insectivorous bats in the Brazilian biome Pampa, in the state of Rio Grande do Sul. Since bat activity can vary according to habitat type, time of year and climatic conditions, the following hypotheses were tested: 1. bat activity varies between different types of habitat; 2. bat activity varies seasonally; 3. bat activity is influenced by temperature, humidity and wind speed. The acoustic samples were taken along fixed transects of 1500 meters, which were monitored monthly from April 2009 to March 2010. Five habitat types were sampled: eucalypts, stream, riparian forest, wetland and grassland. In each sample, the number of bat passes was obtained by using an ultrasound detector Pettersson D230. A total of 1183 bat passes were registered. Greater bat activity levels was observed along large eucalypts (1.93 bat passes/3min) and along a stream (1.61 bat passes/3 min). A riparian forest (0.94 bat passes/3 min) and a wetland area (0.61 bat passes/3 min) exhibited statistically equal levels of activity. Bat passes were fewer in grassland areas (0,16 bat passes/3 min). Bat activity was not correlated with abiotic factors. However, bat activity was significantly low in the colder season, winter, and was similar in autumn, spring and summer. The observed preference for vegetation borders and water courses agrees with reports from other countries and is attributed predominantly to the high prey abundance in these types of environments. Additionally, low activity in the winter is probably a response to the reduced availability of insects, and to lower temperatures. Our results indicate which areas of arboreal vegetation and water courses should be priorities for the conservation of bats and that alterations of these habitat types might negatively influence bat activity in the region

Ecologia alimentar e comportamento de forrageamento de Ameivula aff. ocellifera (Squamata: Teiidae) em área de caatinga do nordeste do Brasil

This study investigated the influence of intrinsic and extrinsic factors on the feeding ecology and foraging behavior of the whiptail lizard Ameivula aff. ocellifera, a new species widely distributed in the Brazilian Caatinga, and that is in process of description. In attendance to the objectives, the Dissertation was structured in two chapters, which correspond to scientific articles, one already published and the other to be submitted for publication. In Chapter 1 were analyzed the general diet composition, the relationship between lizard size and prey size, and the occurrence of sexual and ontogenetic differences in the diet. Chapter 2 contemplates a seasonal analysis of diet composition during two rainy seasons interspersed with a dry season, and the quantitative analysis of foraging behavior during two distinct periods. The diet composition was determined through stomach analysis of lizards (N = 111) collected monthly by active search, between September 2008 and August 2010, in the Estação Ecológica do Seridó (ESEC Seridó), state of Rio Grande do Norte. Foraging behavior was investigated during a rainy and a dry month of 2012 also in ESEC Seridó, by determining percent of time moving (PTM), number of movements per minute (MPM) and prey capture rate by the lizards (N = 28) during foraging. The main prey category in the diet of Ameivula aff. ocellifera was Insect larvae, followed by Orthoptera, Coleoptera and Araneae. Termites (Isoptera) were important only in numeric terms, having negligible volumetric contribution (<2%) and low frequency of occurrence, an uncommon feature among whiptail lizards. Males and females did not differ neither in diet composition nor in foraging behavior. Adults and juveniles ingested similar prey types, but differed in prey size. Maximum and minimum prey sizes were positively correlated with lizard body size, suggesting that in this population individuals experience an ontogenetic change in diet, eating larger prey items while growing, and at the same time excluding smaller ones. The diet showed significant seasonal differences; during the two rainy seasons (2009 and 2010), the predominant prey in diet were Insect larvae, Coleoptera and Orthoptera, while in the dry season the predominant prey were Insect larvae, Hemiptera, Araneae and Orthoptera. The degree of mobility of consumed prey during the rainy seasons was lower, mainly due to a greater consumption of larvae (highly sedentary prey) during these periods. Population niche breadth was higher in the dry season, confirming the theoretical prediction that when food is scarce, the diets tend to be more generalized. Considering the entire sample, Ameivula aff. ocellifera showed 61,0 ± 15,0% PTM, 2,03 ± 0,30 MPM, and captured 0,13 ± 0,14 per minute. Foraging mode was similar to that found for other whiptail lizards regarding PTM, but MPM was relatively superior. Seasonal differences were verified for PTM, which was significantly higher in the rainy season (66,4 ± 12,1) than in the dry season (51,5 ± 15,6). It is possible that this difference represents a behavioral adjustment in response to seasonal variation in the abundance and types of prey available in the environment in each season

Efeitos de diferentes tipos estressores sobre a memória e aprendizagem de ratas

The exposure to stressors produces physiological changes of the organism in order to adapt the individual to the environment. Depending on the type, intensity and duration, stress can affect some cognitive functions, particularly processes of learning and memory. Several studies have also proposed that some level of anxiety would be necessary for memory formation. In this context, memories of previously aversive experiences may determine the manner and intensity with which are expressed fear responses, which explains the great interest in analyzing both anxiety and memory in animals. In addition, males and females demonstrate different reactions in relation to stressful stimuli, showing different levels of anxiety and differences in processing of the acquisition, retention and recall of information. Based on this information, the present study aimed to verify the effect of stress on learning, memory and anxiety behavioral parameters in rats exposed at different types of stressors of long duration (seven consecutive days): restraint (4h/day), overcrowding (18h/day) and social isolation (18h/day) in the different phases of the estrous cycle. Our results showed that the stress induced by restraint and social isolation did not cause changes in the acquisition process, but impaired the recall of memory in rats. Furthermore, it is suggested a protective effect of sex hormones on retrieval of aversive memory, since female rats in proestrus or estrus phase, characterized by high estrogen concentrations, showed no aversive memory deficits. Furthermore, despite the increased plasma levels of corticosterone observed in female rats subjected to restraint stress and social isolation, anxiety levels were unaltered, compared to those various stress conditions. Animal models based on psychological and social stress have been extensively discussed in the literature. Correlate behavioral responses, physiological and psychological have contributed in increasing the understanding of stress-induced psychophysiological disorders

Reconhecimento de seqüências de atividades funcionais em pacientes com acidente cascular encefálico

During the motor rehabilitation of patients with neurological pathologies, there are many factors that have an influence on the therapeutical process. It is possible that the demonstration using videotapes or photographs of movements that will be learned can assist the codification, classification and reorganization of the elements of the task in familiar diagrams and thus facilitate the process of motor rehabilitation. The aim of this study was to analyze the performance in the test of recognition of sequences of functional activities such as water drinking and hair combing presented partially (by photos) and completely (by video) to the patients with encephalic vascular accident . The sample was generated from 12 patients (62 ± 8 years) and 10 healthy subjects (53 ± 5 years), of both sex, divided in two groups for which 5 functional activities were presented partially and completely, in 4 sequences that varied between reached and not reached objectives and correct and incorrect movements, during 24 trials. The test t'Student was applied to verify differences in the recognition time between the groups, and to compare the performance between the tests carried through at 9:00 am and retests at 9:00 am and 4:00 pm. To compare the frequency between the types of reply, the test Qui-square was used. It was verified that the patients presented a greater recognition time and a lower number of correct answers than the healthy subjects, and had better performances in the recognition of the complete sequence than the partial one. Bigger frequency was observed in the reply that the objective and the movement were being presented correctly, however the healthy subjects had soon indicated the correct reply in the first trials. An improvement tendency was observed in the performance, when the stages of tests and retests had been carried through in the same schedule. According to the results, it is suggested that the patients with stroke can better recognize the correct movements of a functional activity when it is presented completely in video form, what can influence the choice of the therapeutical strategy during the process of motor rehabilitation

Correlato hormonal do comportamento reprodutivo de machos de sagüi comum (Callithrix jacchus) em ambiente natural

Contrary to what is recorded for Callithrix jacchus females, the social interactions and hormonal profiles of males are less studied, and mainly in wild groups. The goal of this study was to investigate the behavioral and endocrine profiles of reproductive (RMs) and non-reproductive (NRs) common marmoset adult free-ranging males living in two natural groups (GC1 and GR2). The groups inhabited the area of the Escola Agrícola de Jundiaí/UFRN, located in Macaíba, Brazil. Fecal collection for cortisol and androgen measurement and behavioral monitoring was carried out during the active phase from April to September, 2005. For behavioral data collection the focal instantaneous method was used every 5 min, for a total of 11.563 records. Statistical analysis was performed using non parametric tests and p < 0.05. Besides showing diurnal variation, the frequency of affiliative behaviors was significantly higher for RMs toward reproductive females than for NRs. Affiliative interactions of RMs with both reproductive females and NRs were similar, probably related to pair bond formation and helper recruitment, respectively. Parental care was also similar for both RMs and NRs. Both androgen and cortisol levels increased after the birth of the infants, mainly in RMs. The longitudinal profile of androgens fluctuates more in response to agonistic encounters and sexual behavior than that of cortisol. The mean basal excretion of both hormones was significantly higher in RMs and seems to reflect their higher participation in territorial vigilance and mate guarding behaviors. Significant positive correlations were found between agonism and cortisol and androgen hormones. These results describe, for the first time, the behavioral and hormonal profiles of common marmosets living in free-ranging groups and suggest that reproductive males are more responsive both behaviorally and hormonally to social group dynamics

Reconhecimento de seqüências de atividades funcionais em pacientes com acidente cascular encefálico

During the motor rehabilitation of patients with neurological pathologies, there are many factors that have an influence on the therapeutical process. It is possible that the demonstration using videotapes or photographs of movements that will be learned can assist the codification, classification and reorganization of the elements of the task in familiar diagrams and thus facilitate the process of motor rehabilitation. The aim of this study was to analyze the performance in the test of recognition of sequences of functional activities such as water drinking and hair combing presented partially (by photos) and completely (by video) to the patients with encephalic vascular accident . The sample was generated from 12 patients (62 ± 8 years) and 10 healthy subjects (53 ± 5 years), of both sex, divided in two groups for which 5 functional activities were presented partially and completely, in 4 sequences that varied between reached and not reached objectives and correct and incorrect movements, during 24 trials. The test t'Student was applied to verify differences in the recognition time between the groups, and to compare the performance between the tests carried through at 9:00 am and retests at 9:00 am and 4:00 pm. To compare the frequency between the types of reply, the test Qui-square was used. It was verified that the patients presented a greater recognition time and a lower number of correct answers than the healthy subjects, and had better performances in the recognition of the complete sequence than the partial one. Bigger frequency was observed in the reply that the objective and the movement were being presented correctly, however the healthy subjects had soon indicated the correct reply in the first trials. An improvement tendency was observed in the performance, when the stages of tests and retests had been carried through in the same schedule. According to the results, it is suggested that the patients with stroke can better recognize the correct movements of a functional activity when it is presented completely in video form, what can influence the choice of the therapeutical strategy during the process of motor rehabilitation

Sincronismo comportamental em Boto cinza(Sotalia guianensis)

Synchronism is the efetivation of the same behavior at the same time by two or more individuals. In cetology only from 2000 we verify an increasing of efforts for studies of synchronic behaviors. The synchronism in cetaceans was reported for a variety of contexts, including feeding, socializing, parental care, while resting, traveling and play, during afilliation, in sexual behaviour and possible while teaching. The synchronism in behavior is influenced by environmental factors and can be modified during stress situations such as the presence of boats. The aim of this study is to explore behavior synchronism presented by the estuarine dolphin (Sotalia guianensis) in Pipa, Rio Grande do Norte state, Northeastern Brazil. A total of 414 hours of observation during the year 2006, using scan sampling method, from a land based sighting was conducted. Analyses were conducted in four steps. Firstly, we determined the pattern of activity of the groups within the bay, testing for the influence of bay configuration before and after rains periods on the activity of animals. Analyses show that forage occurs more frequently after the rainy period, but there was no change in the number of individuals or spatial cohesions between them. Secondly, we analysed the influence of turism boat traffic on the behavior of animals. We verified no changes on the bahavior of animals during the presence of boats. Finally, we tested seven hypotheses regarding the ecological and social dynamics of synchronic behavior. Environmental aspects were considered the main influence for the synchronism, no influences of age, and more selective exihibition of synchronic breathing in feeding and social displays were observed during the study period