Avaliação da flotação por ar dissolvido no polimento de efluentes de lagoa de estabilização

Experience in the use of stabilization ponds shows that this is a system with low cost, easy operation and maintenance and suitable for tropical countries. One of its disadvantages is due to high concentrations of suspended solids, mainly due to algal biomass in the effluents. Accordingly, the dissolved air flotation has been shown to be an efficient post-treatment technology. However, the efficiency of this process is related to coagulation and flocculation steps, as well as the adjustment of the involved variables in the process. The objective of this work was to evaluate the algae removal efficiency from wastewater stabilization ponds and the influence of the factors involved in the process using dissolved air flotation. For this, we used primary facultative and maturation effluents of ETE Ponta Negra in Natal. We did tests of coagulation, flocculation and flotation with the samples, using the equipment flotatest. In this process were tested coagulants aluminum sulfate and ferric chloride, and varied the factors pH, coagulant concentration, polymer concentration and rate of recirculation. At the end of the experiments were analyzed turbidity, suspended solids, color, COD and chlorophyll "a". These results were submitted to descriptive statistics to verify the efficiency of the process in general, and regression analysis to identify models that describe the process and demonstrate the factors that have greater influence on flotation. After step methodology, high values were found removal efficiency of suspended solids, reaching values greater than 90% in the best cases. It was concluded that flotation is more efficient in the facultative pond effluent using ferric chloride, and the variability of algae may negatively influence the process. Regression analyzes showed that pH is the most influential variable in the coagulation-flocculation-flotation, and its optimal value among the tested is 5.5 for both coagulants

The Styracaceae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Innovative molecular approach to the identification of Colossoma macropomum and its hybrids

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estrutura genética de Chromis multilineata (Guichenot, 1853) (Perciformes Pomacentridae) na costa NE do Brasil e ilhas oceânicas: evidências de um passado evolutivo instável.

The fauna of Brazilian reef fishes comprises approximately 320 species distributed along the coast of the mainland and islands ocean. Little is known about the levels of connectivity between their populations, but has been given the interest in the relations between the offshore and the islands of the Brazil, in a biogeographical perspective. The oceanic islands Brazilian hosting a considerable number of endemic species, which are locally abundant, and divide a substantial portion of its reef fish fauna with the Western Atlantic. Among the richest families of reef fish in species are Pomacentridae. This study analyzed through analysis of sequences of the mitochondrial DNA control region (D-loop), the standards-breeding population of C. Multilineata in different areas of the NE coast of Brazil, involving both oceanic islands (Fernando de Noronha Archipelago and of St. Peter and St. Paul) and continental shelf (RN and BA). To this aim, partial sequences were used in the region HVR1 of mtDNA (312pb). The population structure and parameters for the estimates of genetic variability, molecular variance (AMOVA), estimation of the index for fixing (FST) and number of migrants were determined. The phylogenetic relationships between the populations were estimated using neighbor-joining (NJ) method. A group of Bayesian analysis was used to verify population structure, according to haplotype frequency of each individual. The genetic variability of populations was extremely high. The populations sampled show moderate genetic structure, with a higher degree of genetic divergence being observed for the sample of the Archipelago of St. Peter and St. Paul. At smaller geographical scale, the sample of Rio Grande do Norte and the Archipelago of Fernando de Noronha do not have genetic differentiation. Three moderately differentiated population groups were identified: a population group (I), formed by the Rio Grande do Norte (I') and the archipelago of Fernando de Noronha (I''), and two other different groups formed by the island population of the archipelago of Saint Peter and St. Paul (II) and Bahia (III). The genetic patterns found suggest that the species has suffered a relatively recent radiation favoring the absence of shared haplotypes. C. multilineata seems to constitute a relatively homogenous population along the West Atlantic coast, with evidence of a moderate population genetic structure in relation to the Archipelago of St. Peter and St. Paul. These data supports the importance of the dispersal larvae by marine current and the interpopulation similarity this species.

Padrões cariotípicos em tetraodontiformes (Osteichthypes) :redução genômica e mecanismos de diversificação

The Tetraodontiformes order is composed for about 400 species of fish, distributed in ten families, with circuntropical distribution. The morphologic diversity of each family reflects in, part, the different levels of specialization. This group represents an ancestry after-Perciformes and constitutes the last branch of the diffusion of the Teleósteos, occupying a position of prominence. The phylogenetics relationships of the Tetraodontiformes exist diverse works examining and, in all, these families are recognized as groups brothers, being Diodontidae next to Tetraodontidae and Balistidae next to Monacanthidae. Although it possesss a representative number of species, the works involving of the families Balistidae and Monacanthidae are few exemplary, especially species of oceanic islands. In this work cytogenetic studies in five species had been analyzed Cantherhines macrocerus, Cantherhines pullus (Monacanthidae), Melichthys niger (Balistidae), Sphoeroides testudíneus (Tetraodontidae) and Chilomycterus antennatus (Diodontidae); through conventional coloration, Ag-NORs and C banding. Ahead of the different karyological trends of evolution presented by the Tetraodontiformes, the present work also searched to verify the relation existence enters the total size of the chromosomes with the amount of DNA in these groups of Tetraodontiformes. For such, they had been correlated the total size of the chromosomes of these species, with values of content of available DNA in literature. The cytogenetics analyses for the species C.macrocerusJ C.pullus (Monacanthidae) and M.niger (Balistidae), had disclosed 40 chromosomes, all acrocentrics. All possess only one pair of NORs and pericentromeric heterochromatin. For S.testudíneus the found dyploid number was equal 2n=46, with NF=78 (16m+18sm+8st+4a), while that for C.antennatus it possesss 2n=50, with NF=76 (4m+22st+24a). Both species possess simple NORs and pericentromeric heterochromatin blocks. In M.niger, the presence of positive marking (heterochromatin and NOR) in the secondary constriction in the second chromosomic pair suggesting the occurrence of a rearrangement, possibly a fusing involving these homologous ones, indicating that these events had been important for the establishment of the karyological history of this group. A maintenance of the chromosomic constancy found in the populations of C.macrocerus (Monacanthidae) and S.testudineus (Tetraodontidae) perhaps if must for the aiding of the gene flow through oceanic chains. These data contrast with the differentiated kinds of chromosomes of C.antennatus between the Northeast coast and Southeastern, suggesting that the ecological standards of each species, added to the conditions of the marine environment, can be responsible for the karyological delineation of each species. The found characteristics for the species C.macrocerus, C.pullus, M.niger, S.testudineus and C.antennatus add it the available data for other species of Tetraodontiformes. From the data gotten in the present study, it can be inferred that the DNA content possesss direct relation with the total length of the chromosomes

Avaliação da genotoxicidade das águas sueprficiais da Barragem Engenheiro Armando Ribeiro Gonçalves, Assu/RN

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Recidiva de câncer labial em pacientes atendidos no hospital DR. Luiz Antônio (Natal-RN) entre 1997-2004

Introduction: Cancer of the lip is very common in tropical countries, being noticeable the squamous cell carcinoma as the main histological type. Objective: Evaluate the socialdemographic profile, habits, occupation, clinical characteristics of the cancer lesions and the aftermath of treatment of the patients treated on the Luiz Antônio Hospital (Natal-RN). Design: Retrospective cohort. Methods: We analyzed 181 medical records of patients from the Luiz Antônio Cancer Hospital (Natal-RN) in the period between 1997 and 2004. The statistic evaluation of time between the diagnosis and the relapse or the cure of the patient were done through the Kaplan-Meier method and the comparison of survivor functions were done through the Log-rank test. Later, was estimated the proportional risk model of Cox. Results: The study population were composed by 69,1% males, 95,2% unlettered, the mean age of 66,5 years, 89,0% of smokers and 64,1% had an occupation involving sun exposure. In regard to the clinical characteristics, most lesions were in the lower lip (77,9%), the size of the tumor was smaller than 2 cm (51,8%), 92,6% had localized lesions. Were verified 16,3% of local relapse and 13% of regional. Almost the totally of the cases corresponded to squamous cell carcinoma (97,2%). We observed smaller accumulated probability of not occurrence of local relapse when the base and borders were free of lesions (p=0,041), as well as a smaller probability of regional relapse when the sort of treatment was surgery, associated with other therapeutics modalities (p=0,001). The patients with advanced pathologic stage (p=0,016), treated with surgery associated with other therapeutics modalities (p=0,001) and diameter above 4cm (p=0,019) presented a bigger possibility of any kind of relapse. The multivariable analysis pointed the complex treatments (surgery plus other therapeutics modalities) as a predictor variable for occurrence of new local lesions (p=0,001) and total (p=0,046), besides the age above 70 years to the regional relapse (p=0,050). Conclusion: Cancer of the lip occur in the lower lip, in males, smokers and individuals exposed to Sun light. The relapse was frequent, even being localized and without great consequences to the patient s health. The probability of relapse is related to the size and borders of the lesion and to the histological exam, as well as to the patient s age and complexity of the treatment chosen

Características da carcaça e qualidade da carne de ovinos terminados em pastagens cultivadas

The objective of this study was to evaluate the quality of housing and the physical and chemical characteristics of meat from sheep raised on pasture Brachiaria brizantha and Panicum maximum. The experiment was conducted in the physical area of the Study Group on Forage (GEFOR), located in the Academic Unit Specialized in Agricultural Sciences - Federal University of Rio Grande do Norte - UFRN in Macaíba, RN, Brazil. We used 32 lambs SPRD, obtained from herds in the state, with liveweight (LW) of 24.5 kg were assigned randomly to four treatments consisting of tropical grasses, two cultivars of Brachiaria brizantha, Marandu and Piatã, and two of Panicum maximum, Aruana and Massai. The experimental area was 2.88 ha, divided into 4 paddocks of 0.72 ha, where each picket consisted of a farm and was divided into six plots of 0.12 ha, where the animals remained under rotational grazing. The period of adaptation to the pickets was seven days. At the beginning of the experiment the animals were weighed, identified with plastic earrings and necklaces colored according to the treatment, and treated against. The lambs were loose in the paddock at 8 am and collected at 16 hours, which returned to collective pens. During the time of grazing animals had free access to mineral supplement with monensin Ovinofós ® and water. Before entering the paddocks of pasture were sampled to characterize the chemical composition. Every seven days occurred at weighing, with fasting, to monitor the weight development. Cultivars Marandu, Aruana, Piatã and Massai were grazed for 133, 129, 143 and 142 days, respectively, until the lambs reach slaughter weight. Arriving at 32 kg lambs were evaluated subjectively for body condition score by, passed through fasting period, diet and water for 16 hours were slaughtered. Measurements were made in the inner and outer casings in addition to subjective evaluations regarding muscling, finish and quantity of pelvic-renal fat, then each was divided longitudinally into two half-carcases and cuts were made in the commercial left half, and after heavy calculated their income. Between the 12th and 13th thoracic vertebrae, was performed a cut to expose the cross section of the Longissimus dorsi, which was drawn on the rib eye area (REA) in transparent film. Fat thickness and extent of AOL GR were determined using a caliper. A tissue composition was determined by dissection of the legs. Analyzes were performed physical (color, cooking loss and shear force) and chemical composition of meat (moisture, ash, protein and lipids) in Longissimus dorsi muscle. Grazing tropical grass Brachiaria brizantha cvs. Marandu and Piatã and Panicum maximum cvs. Aruana and Massai can be used for lambs SRPD in the rainy season, because not alter the physico-chemical and chemical composition of meat

Produção de ovinos em pastagem de capim-massai suplementados na estação seca

The low quality of tropical pastures in the dry season justifies the use of dietary supplements to meet the nutritional needs of sheep to meat production. Therefore, the objective of this experiment was to evaluate the agronomic characteristics of massaigrass in the dry season and the effect of protein supplements in the performance and productivity of sheep to meat production grazing. The protein supplements evaluated were: soybean meal, Leucena hay, Gliricidia hay and multiple mixture. The animals were managed in massaigrass pastures under rotational stocking and supplemented daily. Were used 24 sheep ½ Santa Inês x ½ SPRD (without defined breed), males uncastrated, mean age 90 days in a completely randomized design. Performance of sheep was evaluated for average daily gain of live weight gain per area and stocking rate (animals of 25 kg/ha). The pasture was evaluated for forage mass of pre and post-grazing, the percentages of participation of morphological constituents and their nutritional values and rates of herbage accumulation. The total herbage mass decreased throughout the dry season. Crude protein and in vitro digestibility of organic matter of the leaf were higher in the upper 15 cm of the canopy stratum. The average daily weight gain of the animals supplemented with legume hay was similar to that gained by animals supplemented with soybean meal in the four grazing cycles. The total live weight gain of animals supplemented with legume hay was higher than the animals supplemented only with multiple mixing the first two grazing cycles. Hays of Leucena and Gliricidia can be given for supplementation of sheep maintained on pasture

Dinâmica populacional e alimentar de Stegastes fuscus, (Osteichthyes:pomacentridae) em arrecifes da praia de Búzius, no Rio Grande do Norte

The damselfish, Stegastes fuscus Cuvier, 1830 (Osteichthyes: Perciformes: Pomacentridae), is abundant in the coastal reefs of Búzios Beach, Rio Grande do Norte, Brazil and they play an important role in the reef community ecology. The present study investigated the feeding strategy of this species considering the food habits and morfo-histology of the digestive tract. Influence of the environmental correlates such as temperature, rainfall and luminosity in the tidal rock pools were studied. The fish were captured on a monthly basis from September 2004 to August 2005, during which period 842 individuals of S. fuscus were captured, 125 males, 437 females and 280 individuals without sex identification. The sex ratio observed was 1 M : 3,5 F. The total body length of males varied from 3.6 to 11.3 cm, with a mean of 7.77 cm; that of females varied from 2.9 to 11.4 cm, with a mean of 7.85 cm, and that of sex grouped individuals varied from 2.9 to 11.4 cm, with a mean of 7.83. However, there was no difference between males and females in total body length. This species presented a positive alometric growth and the equations obtained for the relation between body mass and total body length were: Wt =0,0174Lt 3,1123 for males; Wt =0,0137Lt 3,2294 for females and Wt = 0,0148Lt 3.1928 for sex grouped individuals. The relation between total body length and standard length was L t = 1 ,3223Ls + 0,1527 for sex grouped individual s. February to August was associated to a long period of gonadal resting. The fish spawned during January and in September -October. The frequency of fish with empty stomachs occurred during August to December, whereas frequency of fish with food contents i n stomachs occurred during January to July. This species is considered as a preferential herbivore based on the volume of macroalgae in its diet composition. The morfo -histological aspects of S. fuscus confirm herbivory. Among the environmental factors con sidered only rainfall showed a correlation with the feeding habits of this species

Ecologia alimentar do boto cinza, sotalia guianensis (van banédén, 1864), no litoral do rio grande do norte (rn)

This study investigated factors that influence the group size during the behavior foraging of estuarine dolphin Sotalia guianensis in the coast south of the state Rio Grande do Norte (RN), it also characterized the diet of estuarine dolphins and elaborated an otoliths catalog for aid in the identification of the preys found in the stomach contents. In relation to the group size during behaviour foraging, inside of the Curral Bay, larger frequency of solitary hunt was observed. Factors as tide variation, group composition and seasons didn't present correlation with the number of animals observed during a feeding episode. Capture success for participant was shown significantly larger when the animals hunted alone, what possibly explains the largest frequency of solitary hunt inside of the Curral Bay. About diet, were identified 18 bone fishes species, with predominance of species the families Haemulidae and Sciaenidae and five cephalopods species, including two new species in the diet of Sotalia guianensis in Brazil. Our results indicated that estuarine dolphin in the coast oriental from Rio Grande do Norte (RN) feeds predominantly of fish that form shoal, of habitat estuarino and producing of sounds. The analysis of the images, otoliths of 43 species of coastal fish of the coast of the state of Rio Grande do Norte (RN), aided by the offered descriptions, demonstrated to be an effective methodology for the knowledge of those structures, as well as it represented a form of reducing the subjectivity in the identification of the bone fishes found in stomach content

Distribuição espacial, formação de grupos, uso do hábitat e ecologia comportamental de jovens de tubarão limão, negaprion brevirostris (poey 1868), no arquipélago de fernando de noronha

Lemon sharks, Negaprion brevirostris, are common in the Fernando de Noronha Archipelago, but detailed information about the species in this site is lacking. The aim of this study was to describe the spatial distribution, grouping behavior, habitat use and behavioral ecology of juvenile lemon sharks in the archipelago, and their interaction with some environmental and ecological factors. During 2006 and 2007, the presence and spatial distribution of juvenile sharks were quantified through scuba diving and snorkeling at several sites of the archipelago. In 2008 the habitat use of juvenile sharks was quantified through visual census while snorkeling along 300 x 8 m strip transects. During these transects the grouping behavior of lemon sharks was quantified by ad libitum. Results indicate that Fernando de Noronha Archipelago is used as a nursery area for lemon sharks, and the parturition occurs from November to April. Juveniles preferred using shallower areas available by the tide variation and formed groups only in the presence of adult conspecifics. This preference for shallower habitats and the group behavior probably are anti-predatory tactics used by juvenile lemon sharks, in response to the low availability of shelter and high predation risk of the studied areas. Quantifications of prey availability and predation risk of juveniles showed that, in general, lemon sharks are trading-off food by security and investing in sites with higher possibility of energetic return. Behavioral observations enabled to record juvenile carangid fishes following juvenile lemon sharks, remora host-parasite and juvenile sharks foraging on schools of herrings and octopuses. We also recorded the behavior of juvenile sharks following conspecifics of similar size, circling with two or three individuals and smaller individuals giving way to larger juveniles. When adults are present, juvenile lemon sharks are more social than solitary, indicating that predation is one of the factors that contribute to social behaviors of the species. Results also suggest that when grouped the juveniles have a hierarchical organization according to body size. Furthermore, observation of large adult females with several fresh mating bites and scars in the same habitats used by juvenile lemon sharks, indicates that Fernando de Noronha Archipelago is used as nursery and mating grounds by this species

Boto cinza (Sotalia guianensis, Van Benédén, 1864) (Cetacea, Delphinidae): Atividade aérea, forrageio e interações inter-específicas, na Praia de Pipa (Tibau do Sul RN) e estudo comparativo entre duas populações do Nordeste do Brasil

Sotalia guianensis is a small cetacean of the Delphinidae family, with coastal habits and whose area of distribution ranges from Florianópolis (27º35'S, 48º34'W), in Brazil, to Honduras (15º58'N, 85º42'W). At Pipa beach, on the south coast of RN state, in Brazil, the species occur throughout the year. The present study was carried out in two bays, which are bordered by cliffs. The animals were monitored from vantage points, using the "Ad libitum" and "all the occurrences" methods; during the years of 1999 and 2004. The study was divided in 4 chapters: Behavioral standards of two populations of gray dolphin, (Sotalia guianensis, Van Benédén, 1864) in the northeast of Brazil; Aerial activity of the gray dolphin: its possible function and the influence of environmental and behavioral factors; The influence of daily and monthly variation of the tides, of the period of the day and group size on the gray dolphin forage activity; kleptoparasitism interactions of frigatebird (Fregata magnificens, Mattheus, 1914) during the gray dolphin forage activity. The results have shown that the gray dolphin has a varied and complex behavioral repertoire. The leap is the most frequent behavior; the aerial activity is diffuse during daylight and is influenced by some factors, such as the level of the tide and social factors. The gray dolphin, when in the bay, most frequently feeds isolate or in small groups. The forage is diffuse during daylight; however, being more frequent in the morning and is influenced by the daily and monthly variation of the tide. At Pipa beach, kleptoparasitarian interactions were registered between the gray dolphin and the frigatebird (Fregata magnificens). The frigatebird forage strategy consists basically of two ways: to fly over great extensions searching for dead fish and to steal food (kleptoparasitism). These interactions were predominantly carried out between immature and female adult birds and adult and immature dolphins, and occurred during daylight. The present study can be considered an initial landmark to a better knowledge on the gray dolphin surface behavior, especially regarding the aerial behavioral repertoire and forage strategy of this species. However, it is necessary to continue these studies, so that we can understand better the complex social life of these animals and thus create effective measures for its conservation

Estratégia de vida do peixe anual Hypsolebias antenori (Cyprinodontiformes: Rivulidae) do semiárido brasileiro

This work deals with the life strategy of an endangered annual fish, Hypsolebias antenori (Cyprinodontiformes: Rivulidae), of the Brazilian semiarid region. The eggs of these fish hatch at the onset of the rainy season, grows rapidly and they reproduce during the rainy season. When the water puddles dry out, the entire population dies. The resistant eggs which are buried in the bottom of the dried pools go through diapause stages, during which time the embryonic development becomes temporarily arrested. With the onset of the next rainy season, the eggs hatch and a new generation is formed. Specimens of H. antenori were captured during 2011 and 2013, in temporary water pools located in the hydrographic basin of river Jaguaribe in Ceará, Brazil. Sex ratio, the length-weight relationship, the growth type, first sexual maturity, anatomy and histology of the digestive tract, development of gonads, reproductive strategy, karyotypic pattern of the species, and the conservation status of H. antenori were investigated. The results of this study are presented in the form of eight articles. The first article is about the fish faunal composition of the hydrographic basins of Rio Grande do Norte, Brazil, wherein the record of H. antenori is included. The second article deals with the sex ratio, secondary sexual characteristics of males, the length-weight relationship and the type of growth. Males show a pattern of intense coloration with well developed fins. The sex ratio showed a significant predominance of females (1M:1.7 F). Males were larger in length and weight. The equation of weight and total length relationship was Wt=0.0271Lt3,8937, showing a positively allometric growth, indicating greater increase in weight than in length. The third article discusses the anatomy and histology of the digestive tract of H. antenori. It is considered as a generalist feeder with characteristics of omnivore, which utilizes different food sources. The fourth article discusses the stages and phases of gonad development and type of spawning of H. antenori. The fifth article is about the r reproductive strategy adopted by H. antenori which helps in successful reproduction over a short period of life. The sixth article deals karyotypic pattern of the species, constituting the first cytogenetic contribution to the genus. The seventh article discusses about the risk of extinction of this species which suffers a series of threats, such as, habitat loss through land use, deforestation, construction of reservoirs, pollution due to domestic and industrial sewage, besides pesticides and agrochemicals. Furthermore, decreasing rainfall and intensification of aridity due to global climate changes, interferes with the reproductive cycle. The eighth article deals with aggressive behavior adopted between males and among females during reproduction. All temporary water pools sampled during this study were in high degree of degradation, mainly due to human action. There is a great need for conservation measures to protect the populations of annual fish, including the creation of protected areas in the semiarid ephemeral aquatic environments of Brazil

Comportamento social de botos-cinza, sotalia guianensis, na praia de Pipa, RN, Brasil: dinâmica, sequência, sincronia e respostas ao turismo de observação

Social behavior of Guiana dolphins, Sotalia guianensis, at Pipa Beach, RN, Brazil: dynamics, sequence, breathing synchrony, and responses to dolphin watching. Social animals form groups that can range from temporary to permanent. Depending on the nature of the social relationships developed between individuals, groups present a particular social organization and the effect of these interactions shapes the activity patterns of these animals. This study investigates: (i) fission-fusion dynamics of Guiana dolphins, through the analysis of three dimensions of the social system (variation in spatial cohesion, variation in size and composition of groups), (ii) sequence, routine and behavioral stability, (iii) breathing intervals in synchronized groups and (iv) behavioral responses of the animals to dolphin watching. Systematic observations of Guiana dolphins were made from a platform located in cliffs about 25 m above sea level that surround Madeiro Bay, Pipa Beach. Sampling occurred from December 2007 to February 2009 between 0600 h and 1600 h, and the groups of Guiana dolphins were investigated according to their size (alone and group) and composition (adults, adults and juveniles, and adults and calves). According to the analysis of fission-fusion dynamics, Guiana dolphin groups frequently changed their composition, modifying their patterns of spatial grouping and cohesion every 20 minutes on average. More than 50% of the individuals maintained a distance of up to 2 m from other group members and new individuals were attracted to the group, especially during feeding, leaving it for foraging. Large groups were more unstable than small, while groups containing only adults were more stable than groups of adults and juveniles. According to the Z-score analysis to investigate the sequence and behavioral routine, lone individuals were more ! .7! ! involved in foraging and feeding, while resting was more common in groups. Foraging and feeding were more common in homogeneous groups (individuals of the same age class), while heterogeneous groups (different age classes) were often involved in socialization, displaying a broader behavioral repertoire. Foraging and resting behavior presented higher stability (continuous duration in minutes) than the other behaviors. The analysis of breathing intervals in synchronized groups showed significant differences depending on type of behavior, composition and area preference. During resting, breathing intervals were of longer duration, and groups with calves showed shorter breathing intervals than groups without calves. Lone individuals also preferred areas called corral , often used for the entrapment of fishes. The Markov chain analysis revealed behavioral changes in the presence of boats, according to the type of group composition. Groups composed of adults presented decreased resting and increased in traveling during the presence of boats. Groups of adults and juveniles showed a massive reduction of socialization, while the behavior transition probability traveling-traveling was higher in groups of adults and calves. In the presence of the boats, stability of resting was reduced by one third of its original duration and traveling more than doubled. The behavioral patterns analyzed are discussed in light of socio-ecological models concerning costs and benefits of proximity between individuals and behavioral optimization. Furthermore, significant changes in behavioral patterns indicate that Guiana dolphins, at Pipa Beach, have suffered the effects of tourism as a result of violation of rules of conduct established for the study area