Estudo sobre orçamento de atividade do Boto Cinza (Sotalia guianensis) no litoral sul do Rio Grande do Norte

A fundamental analysis on Behavioral Ecology is the construction of Activities Budget, which can be defined as the quantification of the time that each animal uses in activities that are important for its survival and reproduction. Initially developed for theoretical studies about Optimal Foraging, the construction of Activities Budgets has recently being used for analyses in Conservation Biology. However, the measurement of behavior through an adequate methodology that allows the comparison between different samples is a challenge for researchers in the area of Ethology. This problem is even bigger for the students of cetaceans behavior due to the difficulty of visualization of these animals. The present work deals with two aspects of the specialized literature on cetaceans: i) it explores possible variations of results in quantification of behavioral states decurrent of the application of different methods of data collection, and ii) it describes the activity budget of a population of Sotalia guianensis that inhabits coastal waters, south Rio Grande do Norte. The results showed that the use different methods of data collection result in significant differences, but of small scale, in the quantification of the behavioral frequency. The activity budget of Sotalia in the area here analyzed was similar to that described for other populations of this species inhabiting typically estuarine habitats. Tide and day-hour did not influence the dolphin s behavior, however, significant differences were found related to the position of the animals within the area. These results are discussed considering the dietary and behavioral flexibility of the species, contributing to the scientific knowledge and offering information that will be useful in comparative studies and for analyses on the determination of areas for species conservation

Helminths of Sotalia guianensis (Cetacea: Delphinidae) from the South and Southeastern Coasts of Brazil

From May 1997 to October 2000, 49 Sotalia guianensis (tucuxi dolphin) incidentally caught in fishing nets or stranded in Sao Paulo (SP) and Parana (PH) states in Brazil were necropsied. In total, 17 lungs, 35 stomachs, and 30 intestines were analyzed. Contents were washed through a sieve (mesh, 150 mm) and examined under a stereoscopic microscope for parasites. Histopathologic analyses were performed in the lungs of five infected dolphins. The nematode Halocereus brasiliensis was found in 88% of all lungs examined, inducing moderate-to-severe pneumonia. Braunina cordiformis, Anisakis sp., and acanthocephalans were found in the stomachs. The trematode Synthesium tursionis was the only parasite found in the intestines, and it was identified in 73% of the animals necropsied. No macroscopic lesions were seen due to parasites in the stomachs and intestines analyzed.

Padrões de uso de habitat do boto-cinza (Sotalia guianensis) na região da foz do rio Doce, costa norte do Espírito Santo, Sudeste do Brasil

Entre março de 2011 e dezembro de 2012 foram realizadas 30 saídas de campo para avaliar os padrões de uso de habitat e estrutura de grupo de Sotalia guianensis na região da foz do rio Doce, costa norte do Espírito Santo. A coleta de dados foi realizada com auxílio de uma embarcação a partir de rotas pré-determinadas distribuídas homogeneamente na área de estudo. Informações sobre as variáveis ambientais foram coletadas a cada hora de amostragem e a cada grupo de golfinhos avistado. Através da análise de Cluster foram identificados três diferentes habitats baseados na similaridade entre variáveis ambientais. Durante 242hs48min de amostragem foram percorridos 1.523km e 119 grupos de botos-cinza foram avistados. Grupos de Sotalia guianensis, assim como indivíduos imaturos, foram observados ao longo de todo o ano na área de estudo, não apresentando diferença sazonal entre as estações seca (abril a setembro) e chuvosa (outubro a março). Os grupos apresentaram uma média de 9,9 indivíduos. Animais imaturos estavam presentes na maioria dos grupos (71%), apresentando uma relação direta com o número de adultos. Os botos-cinza apresentaram o uso quase exclusivo da região marinha aberta adjacente à desembocadura do rio apontando um padrão de uso de habitats heterogêneo, onde as áreas de maior concentração de golfinhos não corresponderam às áreas preferenciais de alimentação. Os resultados obtidos neste trabalho refletem como S. guianensis responde a complexidade dos fatores bióticos e abióticos da área de estudo, apontando um padrão de uso de habitat diferenciado para a espécie.

Prey consumed by Guiana dolphin Sotalia guianensis (Cetacea, Delphinidae) and franciscana dolphin Pontoporia blainvillei (Cetacea, Pontoporiidae) in an estuarine environment in southern Brazil

The present study provides information about the diet of sympatric populations of small cetaceans in the Babitonga Bay estuary. This is the first study on the diet of these species in direct sympatry. The stomach contents of seven Guiana dolphins Sotalia guianensis and eight franciscanas Pontoporia blainvillei were analyzed. The prey of both cetaceans was mostly teleost fishes, followed by cephalopods. We identified 13 teleost fishes as part of the diet of the franciscanas, and 20 as part of the diet of Guiana dolphins. Lolliguncula brevis was the only cephalopod recorded, and was the most important prey for both cetaceans. Stellifer rastrifer and Gobionellus oceanicus were also important for franciscana, so as Mugil curema and Micropogonias furnieri were important for Guiana dolphins. Stellifer rastrifer and Cetengraulis edentulus were the fishes with the highest frequency of occurrence for franciscana (50%), while Achirus lineatus, C. edentulus, S. brasiliensis, Cynoscion leiarchus, M. furnieri, M. curema, Diapterus rhombeus, Eugerres brasilianus and G. oceanicus showed 28.6% of frequency of occurrence for Guiana dolphins. Franciscanas captured greater cephalopods than the Guiana dolphins in both total length (z= -3.38; n= 40; p< 0.05) and biomass (z = -2.46; n = 40; p<0.05). All of the prey species identified occur inside the estuary, which represents a safe habitat against predators and food availability, reinforcing the importance of the Babitonga Bay for these cetacean populations.

Osteological alterations in the tucuxi Sotalia fluviatilis (cetacea, delphinidae)

We present a description of osteological alterations observed in the tucuxi, Sotalia fluviatilis (Gervais, 1853) from a sample of 43 specimens. Fractures were the most frequent alterations in the sample (16%), occurring in various regions of the skeleton such as the ribs, hyoid apparatus, transverse and neural processes of vertebrae and scapula. We observed three individuals with ankylosis between the cervical vertebrae and two individuals with morphological changes (cranio-caudally elongated hemal arch and flattened cranial margin of the scapula). The only observed pathology was a case of osteomyelitis in the left dentary, which caused the loss of teeth, deformation of the associated alveoli and the formation of a medial fistula (lingual) for drainage of purulent material. This represents the first record of osteomyelitis in S. fluviatilis.

Anomalias ósseas congênitas em Sotalia guianensis (Mammalia, Cetacea, Delphinidae) da costa centro-norte do Estado do Rio de Janeiro

Carcaças de botos-cinza Sotalia guianensis (van Bénéden, 1864) foram recuperadas entre 20 de agosto de 2001 e 13 de fevereiro de 2006, na costa centro-norte fluminense. A maior parte delas (85%) entre Barra de São João (22º35'S 41º59'W) e Quissamã (22º06'S 41º28'W). Foram estudadas as colunas vertebrais dos 20 exemplares que apresentavam mais de 60% das vértebras presentes. A coleção é formada por 75% de animais imaturos, e todos os esqueletos mostram alterações tafonômicas mínimas. Duas categorias de anomalias congênitas foram diagnosticadas, ambas relacionadas ao desenvolvimento do mesoderma paraxial. A sétima vértebra cervical (C7) foi a única afetada, as costelas cervicais e o não fechamento do arco neural atingiram 15 (75%) dos indivíduos analisados, dos quais três (15%) apresentam ambas as anomalias. Nove (45%) indivíduos apresentaram costelas cervicais uni ou bilateral, e nove (45%) indivíduos apresentaram não fechamento do arco neural; em todos os casos as vértebras contíguas eram normais. A ocorrência de anomalias nesta série do Rio de Janeiro é maior do que as referidas na literatura brasileira para outras séries de Sotalia do Amazonas, Ceará e Santa Catarina. A série de Sotalia descrita vem de uma região do litoral muito limitada e provavelmente representa uma população local. As costelas cervicais são geneticamente determinadas e podem estar concentradas por uma condição de grande proximidade biológica entre os animais; o não fechamento do arco pode ter também um componente ambiental, a ser investigado futuramente.

Social organization of marine Tucuxi dolphins, Sotalia guianensis, in the Cananeia Estuary of southeastern Brazil

Social organization is an important component of the population biology of a species that influences gene flow, the spatial pattern and scale of movements, and the effects of predation or exploitation by humans. An important element of social structure in mammals is group fidelity, which can be quantified through association indices. To describe the social organization of marine tucuxi dolphins (Sotalia guianensis) found in the Cananeia estuary, southeastern Brazil, association indices were applied to photo-identification data to characterize the temporal stability of relationships among members of this population. Eighty-seven days of fieldwork were conducted from May 2000 to July 2003, resulting in direct observations of 374 distinct groups. A total of 138 dolphins were identified on 1-38 distinct field days. Lone dolphins were rarely seen, whereas groups were composed of up to 60 individuals (mean +/- 1 SD = 12.4 +/- 11.4 individuals per group). A total of 29,327 photographs were analyzed, of which 6,312 (21.5%) were considered useful for identifying individuals. Half-weight and simple ratio indices were used to investigate associations among S. guianensis as revealed by the entire data set, data from the core study site, and data from groups composed of <= 10 individuals. Monte Carlo methods indicated that only 3 (9.3%) of 32 association matrices differed significantly from expectations based on random association. Thus, our study suggests that stable associations are not characteristic of S. guianensis in the Cananeia estuary.

Efficiency of wear and decalcification technique for estimating the age of estuarine dolphin Sotalia guianensis

Most techniques used for estimating the age of Sotalia guianensis (van B,n,den, 1864) (Cetacea; Delphinidae) are very expensive, and require sophisticated equipment for preparing histological sections of teeth. The objective of this study was to test a more affordable and much simpler method, involving of the manual wear of teeth followed by decalcification and observation under a stereomicroscope. This technique has been employed successfully with larger species of Odontoceti. Twenty-six specimens were selected, and one tooth of each specimen was worn and demineralized for growth layers reading. Growth layers were evidenced in all specimens; however, in 4 of the 26 teeth, not all the layers could be clearly observed. In these teeth, there was a significant decrease of growth layer group thickness, thus hindering the layers count. The juxtaposition of layers hindered the reading of larger numbers of layers by the wear and decalcification technique. Analysis of more than 17 layers in a single tooth proved inconclusive. The method applied here proved to be efficient in estimating the age of Sotalia guianensis individuals younger than 18 years. This method could simplify the study of the age structure of the overall population, and allows the use of the more expensive methodologies to be confined to more specific studies of older specimens. It also enables the classification of the calf, young and adult classes, which is important for general population studies.

Purificação e caracterização de uma ß-N-acetillhexosaminadase extraída do mamífero marinho Sotalia fluviatilis

This report shows 2232 times purification of a βNAcetylhexosaminidase from hepatic extracts from the sea mammal Sotalia fluviatilis homogenate with final recovery of 8,4%. Sequenced steps were utilized for enzyme purification: ammonium sulfate fractionation, Biogel A 1.5 m, chitin, DEAESepharose and hydroxyapatite chromatographies. The protein molecular mass was estimated in 10 kDa using SDSPAGE and confirmed by MALDITOF. It was found to have an optimal pH of 5.0 and a temperature of 60°C. Using pnitrophenylNAcetylβDglycosaminide apparent Km and Vmax values were of 2.72 mM and 0.572 nmol/mg/min, respectively. The enzyme was inhibited by mercury chloride (HgCl2) and sodium dodecil sulfate (SDS)

Etnobiologia do boto cinza (Sotalia guianensis, van Bénéden, 1864) por comunidades pesqueiras do Rio Grande do Norte, Basil

Ethnobiology studies Local Ecological Knowledge (LEK) as well as the use and management of natural resources by local communities in order to understand how the environment is perceived, known and classified by human groups. In fishing communities, LEK adds empirical information about the biology of aquatic species and complements scientific findings, especially when it is difficult to obtain factual information during studies on cetaceans, whose behavior is essentially underwater. Cetaceans (whales and dolphins) are constantly threatened by human activities, especially by accidental capture of small coastal species, as in the case of the estuarine dolphin (Sotalia guianensis), object of this study. Ethnobiological researches in fishing communities are of great importance and can clarify aspects of the biology and conservation of this species. Although extensively studied throughout its distribution range, there are still gaps in the knowledge about S. guianensis. Therefore, fishers local ecological knowledge becomes an additional tool to get and confirm information about S. guianensis. This study evaluated the LEK of artisanal fishers who are daily exposed to local population of S. guianensis, through the use of semistructured interviews (N=116). The interviewed fishers were asked about the biology and popular classification of S. guianensis and about possible interactions between this dolphin and them. The studied communities were located in Tibau do Sul (n=39), Pipa (n=36) and Baía Formosa (n=41), all on the south coast of Rio Grande do Norte, Brazil. The study was based on the assumption that differences in fishers LEK among those communities would be caused by both the variety of fishing environments (lagoon/estuary and ocean) and the intensity of tourism activities. Fishers knowledge is expressive and differed among the studied communities depending on the topic investigated. Fishers correctly reported the habitat, distribution, seasonality and behavioral particularities of S. guianensis. Tourism mainly affected the naming of the species. The study results also suggest that marine fishers have greater knowledge about the species than the estuarine/lagoon ones. Local populations accumulate empirical knowledge according to their environment. Hence, it is important to take into account both empirical knowledge and popular participation in management systems, in order to maintain information sharing among communities

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

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

Uso de habitat, orçamento temporal e influência da maré da geomorfologia do fundo sobre o comportamento do boto Sotalia guianensis Van Bénéden, 1864 (Cetacea: Delphinidae) no Porto de Maceió - Alagoas, Brasil

The physical and environmental factors presented by each habitat and the rhythm of behavior patterns strongly influence the ecology and behavior of the all living beings. At same time this factors may provide clues about the structure of a population and its ecological balance. The organizational structure, ecology and behavior of a species appraised in a region if we know be in balance when compared to the same type of appraisal made in a degraded area can provide a clear view of how the anthropogenic influences acted on these species and what steps can be taken in order to mitigate the effects and keep the population. The region where this study was conducted is, like most areas of port, subject to intense physical and environmental degradation. With the emerging interest of change in the quality of these environments also by the companies themselves that use the port services, the proposed study aimed to characterize the use of habitat, the distribution of behavioral activities carried out throughout the day and influence of geomorphology of the bed, depth and variation of tide on the expression of the behavior of Sotalia guianensis in the port of Maceio - Alagoas. From this information will be possible establish parameters for comparison with other populations of S. guianensis and establish conservation measures for the population occurring in the port of Maceio - AL, serving also as a basis for conservation actions future performed in other port regions

Caracterização do repertório acústico do botocinza, sotalia guianensis, e impacto de embarcações no nordeste do brasil

The wide distribution along the Brazilian coast of specie Sotalia guianensis has been growing interest in searchers on the ecology of this species, addition to commercial interests by whalewatching. This work described the accoustic repertory of S. guianensis and their behavior associated and found if underwater noises affect this repertorie in Pipa-RN. It were analyzed 18:49h of recordings maked between april and june/2009. It were found 3258 whistles, 289 calls, 873 clicks and no gargle. The frequencies range of guiana dolphins was 1 a 48kHz and may be related to system response recorder and population s regionalization. The frequencies overlaps the noise made by motorboats, schooners and water bomb. The behavior travelling ocurred siletly in 72,58% and socialization presented no sound (56,4%) and presence of sound (43,6%). This great absence of sound may be relacioned to saving energy, probably because in this behaviors they can use physical and visual contacts. The foraging presented highest records of all class noise with 46,84% clicks, 33,84% whistles and 9,02% calls. All this sounds occurred differently in each behavior (travelling: x2 = 134,35 df = 3 p = 0,0001; foraging: x2 = 19,83 df = 3 p= 0,00018 and socialization x2 = 60,35 df = 3 p = 0,0001). It was possible to determine that underwater noise cause changes in the repertorie and does a considerable increase in whistle s number and reduce clicks. Also occurs changes in some whistles (FI: t=2,42, p=0,015; FF: t= -2,22, p=0,025), calls (FMI: t= -3,13, p=0,001; FMA: t= -3,49, p=0,0005; FD: t= -2,21, p=0,027; D: t=2,89, p=0,004) and clicks parameters (D: t= -3,85, p=0,0001; I: t= -5,32, p=0,0001) during presence of noise. These changes may be a strategy of these animals to win this sound barrier. We can not say which noise has more impact, ix however the water bomb seems to affect more the clicks and the motorboats seems to affect the others sounds. Little is know about auditive sensibility of this specie, but daily exposure to this noise may cause damage and this specie appears to have residence. The specie conservation is necessary because the population already seems to suffer damage as decrease in length of stay, number of individuals entering the inlet and the apparent diminution in the foragind during vessels presence and control standards and ambiental education can help. So, we can advance in knowledge about the ecology of this specie especially when it come to bioacoustics and their behaviors associated and reveals some of the impacts that the noise have brought to this population