130 resultados para Sotalia fluviatilis


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Whistles were recorded and analyzed from free-ranging single or mixed species groups of boto and tucuxi in the Peruvian Amazon, with sonograms presented. Analysis revealed whistles recorded falling into two discrete groups: a low-frequency group with maximum frequency below 5 kHz, and a high-frequency group with maximum frequencies above 8 kHz and usually above 10 kHz. Whistles in the two groups differed significantly in all five measured variables (beginning frequency, end frequency, minimum frequency, maximum frequency, and duration). Comparisons with Published details of whistles by other platanistoid river dolphins and by oceanic dolphins suggest that the low-frequency whistles were produced by boto, the high-frequency whistles by tucuxi. Tape recordings obtained on three occasions when only one species was present tentatively support this conclusion, but it is emphasized that this is based on few data. (C) 2001 Acoustical Society of America.

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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)

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Dolphins of the genus Sotalia are found along the Caribbean and Atlantic coasts of Central and South America and in the Amazon River and most of its tributaries. At present, the taxonomy of these dolphins remains unresolved. Although five species were described in the late 1800s, only one species is recognized currently (Sotalia fluviatilis) with two ecotypes or subspecies, the coastal subspecies (Sotalia fluviatilis guianensis) and the riverine subspecies (Sotalia fluviatilis fluviatilis). Recent morphometric analyses, as well as mitochondrial DNA analysis, suggested recognition of each subspecies as separate species. Here we review the history of the classification of this genus and present new genetic evidence from ten nuclear and three mitochondrial genes supporting the elevation of each subspecies to the species level under the Genealogical/Lineage Concordance Species Concept and the criterion of irreversible divergence. We also review additional evidence for this taxonomic revision from previously published and unpublished genetic, morphological, and ecological studies. We propose the common name costero for the coastal species, Sotalia guianensis (Van Beneden 1864), and accept the previously proposed tucuxi dolphin, Sotalia fluviatilis (Gervais, 1853), for the riverine species.

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The appearances of the gonads are described in males and females of 18 Inia geoffrensis, 11 Pontoporia blainvillei, and eight Sotalia fluviatilis from South America. Males of I. geoffrensis become sexually active at a length of about 228 centimeters, females at 175 to 180 centimeters. Length at birth is 76 to 80 centimeters; parturition occurs from about July to September in the upper Amazon. Males of P. blainvillei are still sexually immature at a length of 128.5 centimeters, females become sexually active at a length of 137 centimeters. Off Uruguay, pregnant females have fetuses 6 centimeters in length in February and 61 centimeters in October. Males of S. fluviatilis are sexually active at a length of 148 centimeters, females at 140 centimeters. Gonad weights and details of corpora lutea and albicantia are given. Corpora albicantia appear to persist as in other cetaceans. The ovaries of I. geoffrensis are relatively bulky with the corpora enclosed in the ovarian substance and not pedunculated as in P. blainvillei and S. fluviatilis in which the right ovary is poorly developed.

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A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

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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)

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O turismo vem sendo considerado como solução de problemas econômicos em muitas comunidades de baixa renda, mas também pode ser causador de impactos negativos. O condicionamento de animais selvagens através da alimentação artificial facilita o trabalho dos operadores de turismo de natureza ao criar mais situações de encontro e diminuir as distâncias entre os turistas e esses animais, mas casos ao redor do mundo demonstram numerosos impactos negativos resultantes de tais atividades. No estado do Amazonas, Brasil, cinco casos de atividade turística onde botos-da-Amazônia (Inia geoffrensis) foram condicionados ao contato humano através da alimentação articial vêm ocorrendo, sendo o caso do Parque Nacional de Anavilhanas (PNA), em Novo Airão (NA), o precursor. Assim, os objetivos da presente tese são: descrever os casos de condicionamento de botos como atração turística no estado do Amazonas, avaliar se as atividades turísticas de alimentação artificial influenciam a agressividade e o comportamento social dos botos condicionados do PNA, produzir uma avaliação acurada da percepção da comunidade local de NA com relação aos possíveis impactos socioeconômicos desta atividade turística, acessar a percepção dos pescadores locais quanto às interações entre cetáceos (incluindo o tucuxi, Sotalia fluviatilis) e atividades de pesca e os impactos do condicionamento de botos nessas interações, na região de NA e conduzir uma análise das expectativas prévias e experiências realizadas pelos turistas participantes das atividades de interação com os botos em NA, avaliando também sua percepção geral sobre este tipo de turismo, em especial com relação à sua proximidade com os animais. Os métodos utilizados para a coleta dos dados foram: entrevistas etnográficas semi-estruturadas, observação participante, questionários auto-aplicáveis e métodos de amostragem comportamental. Os resultados demonstraram que as atividades baseadas no condicionamento geram vários impactos negativos. Pode-se concluir que a atividade turística baseada no condicionamento de botos através da alimentação artificial: tem se dispersado pelo estado do Amazonas ao longo dos últimos anos, altera o comportamento social e causa o aumento da competição entre os botos condicionados em NA, apesar de gerar empatia pelo boto em parte da população de Novo Airão, é percebida pelos moradores como gerando poucos benefícios econômicos, sendo que a maioria se sente excluída do compartilhamento de benefícios gerados pela mesma, aparentemente não resulta em uma grande mudança na percepção negativa dos botos por parte dos pescadores, que também se percebem como estando excluídos do compartilhamento de benefícios gerados pela atividade e geram um alto grau de satisfação nos turistas participantes e atendem às atuais expectativas dos turistas, mas através de atividades invasivas que provavelmente disseminam a ideia de que condicionar animais silvestres ao contato humano através da alimentação artificial é correto. Assim, possivelmente a atividade em questão não está em completo acordo com as leis brasileiras, conceitos de ecoturismo e funções das unidades de conservação. Propostas de manejo para superar a controversa questão relacionada à alimentação artificial como prática turística e fortalecimento de práticas menos negativamente impactantes de caráter participativo para NA são sugeridas.

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Addition of three species to the list is recommended based on recent literature. (Orcaella brevirostris) has been split into the Irrawaddy dolphin (O. brevirostris) and the Australian snubfin dolphin (O. heinsohni). Sotalia fluviatilis has been split into the riverine tucuxi (S. fluviatilis) and the marine "costero" (S. guianensis). Evidence to support both of these splits is convincing, and we recommend that they be recognized in the list. The existence of the Bryde's-whale-like species described in 2003 as Balaenoptera omurai has been confirmed with additional genetic (nuclear) data. While the species clearly exists, the nomenclature is still unsettled because the genetic identity of the holotype specimen of Balaenoptera edeni has not yet been determined. However, the name B. omurai is gaining wide usage in application to the new species, and we propose that it be used provisionally by the Scientific Committee pending the genetic identification of the B. edeni holotype. We recommend that India be urged to facilitate the identification. We recommend continued use of the name Balaenoptera edeni provisionally for both the "ordinary" large form and the small coastal form, recognizing that further genetic and morphological research may justify recognition of two species: B. brydei and B. edeni. We also recommend that any new specimen be referred to B. omurai only after its mtDNA has been sequenced and found to support the identification.

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The State of Sao Paulo is the most developed area in Brazil and was impacted by persistent organic pollutants for several decades. This study investigated organochlorines in five species of small cetaceans (Pontoporia blainvillei, Stenella frontalis, Sotalia guianensis, Tursiops truncatus and Steno bredanensis) found dead along the coast of Sao Paulo between 1997 and 2003. DDTs (15.9 mu g g(-1) lipid: mean for all pooled individuals) and PCBs (8.08 mu g g(-1)) exhibited the highest concentrations in the animals, reflecting large amounts formerly used in Brazil. Lower levels of mirex (0.149 mu g g(-1)), HCB (0.051 mu g g(-1)), CHLs (0.008 mu g g(-1)) and HCHs (0.007 mu g g(-1)) were detected in all species. Residual pattern of DDTs in dolphins suggests that o,p`-DDT is more recalcitrant than p,p`-DDT in the body of the animals and/or the environment. In contrast to p,p`-DDT, residues of o,p`-DDT seem to be preferentially converted into o,p`-DDD rather than op-DDE. (C) 2010 Elsevier Ltd. All rights reserved.

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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.

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Diurnal periodicity of spawning in the perch so far are rather meagre and found to be partly contrary to experiences of perch anglers. Therefore a study was made on the spawning during a 5-day period in the spring of 1971 in the Kuusamo area. Observations were made during the main spawning season, between 4- 9 June 1971. The perch were often measured, weighed and then released back into the water. The differences between spawning and non-spawning perch were studied as well as the time of roe discharge in a 24 hour period. Activity and environmental factors such as light intensity were also taken into consideration.

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Since 1967 data have been collected on the distribution of fish caught in a 24 hour period during the winter angling season. The present study on activity periods is based on data from nearly 2000 perch collected between 1967 and 1971. The distribution of number of fish caught during 24 hrs during December - May was studied. Of the total, the most productive period was found to be between 0600 - l600 hrs., with the peak period occurring between 0800 - 1000 hrs. The present data together show that during the darkest months of the year, the perch is only active in the mid-day period. Throughout the whole winter fishing season, activity only occurs during the time between surise and sunset.

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The most common catch of the amateur angler is the perch and it is the diurnal periodicity of activity (& catchability) which is examined in this study based on earlier articles and manuscripts by the authors. Of all environmental factors, variation in light and temperature are the chief reasons in establishing the times of activity periods. Winter, summer and autumn activity was studied. The spawning perch was found to be more active than the non-spawning perch. The time of day in which the fish may be active is dependant on its ability to sense changes in the external environment. Its adaptation to light is the reason for day-activity in the winter, and also accounts for the fact that hardly any activity occurs between sunset and sunrise when this period exceeds 6 hours.

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Catchability and activity of Perca fluviatilis in relation to temperature is examined. The number of fish caught and water temperature during the 3 summer months was used the assess the numbers of hours of activity of perch. Parallel to the research on activity, large-scale marking was carried out to establish the periods of growth during the year.

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Concentrações de compostos organoclorados (DDTs, PCBs, HCHs, Mirex e HCB) foram determinadas em camadas externas e internas do tecido adiposo subcutâneo de 17 botos-cinza (Sotalia guianensis) da região Sudeste do Brasil. Não houve diferenças estatísticas significativas entre os estratos, relativo aos 37 compostos determinados, assim como ΣDDT, ΣPCB, ΣHCH, e as razões p,p-DDE/ΣDDT e ΣDDT/ΣPCB. Entretanto, foram observadas diferenças significativas nas concentrações de alguns compostos organoclorados de animais encalhados ou capturados acidentalmente quando comparados com animais biopsiados remotamente, sendo assim as comparações entre esses dois conjuntos de dados, devem ser vistas com cuidado. No presente estudo, as concentrações dos compostos organoclorados foram determinadas em biópsias de botos-cinza obtidas de 2007 a 2009, nas baías de Sepetiba (n=13) e Ilha Grande (n=11), Sudeste do Brasil. As concentrações (ng/g de lipídio) variaram de