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 são paulo (sp) and paraná (pr) 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 halocercus brasiliensis was found in 88% of ...201020688658
seasonal variations in spatial usage by the estuarine dolphin, sotalia guianensis (van bénéden, 1864) (cetacea; delphinidae) at its southern limit of distribution.the use of space by the resident population of estuarine dolphins (sotalia guianensis) in norte bay, southern brazil was studied by boat surveys between 2000 and 2003. data such as the geographical position and group size was collected at 5-minute intervals using focal-group sampling. the distribution and seasonal and daily group home-ranges were estimated using a gis (geographic information system) environment. the dolphins did not use the area homogeneously, restricting their activities to a w ...200717505744
lesions associated with halocercus brasiliensis lins de almeida, 1933 in the lungs of dolphins stranded in the northeast of brazil.the parasitic fauna of cetaceans is an important tool for ecological studies, including analyses on the causes of death. halocercus brasiliensis is a nematode frequently found in the bronchi and bronchioles of some cetaceans, and it is commonly associated with focal inflammation of the respiratory tract leading to bacterial pneumonia and septicemia and, sometimes, to death. the objective of this study was to report infections by h. brasiliensis in the respiratory tract of delphinidae stranded on ...201525171594
novel cetacean morbillivirus in guiana dolphin, brazil. 201424565559
cetacean morbillivirus: current knowledge and future directions.we review the molecular and epidemiological characteristics of cetacean morbillivirus (cemv) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. cemv has caused epidemics with high mortality in odontocetes in europe, the usa and australia. it represents a distinct species within the morbillivirus genus. although most cemv strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from indo-pa ...201425533660
contamination by persistent organochlorines in cetaceans incidentally caught along brazilian coastal waters.wide ranges of organochlorine residues were determined in the blubber of franciscana (pontoporia blainvillei), estuarine dolphin (sotalia guianensis), atlantic spotted dolphin (stenella frontalis), and long-beaked common dolphin (delphinus capensis) incidentally caught along brazilian coastal waters. concentrations of ddts and pcbs were the highest, followed by chls, tcpmoh, dieldrin, tcpme, heptachlor epoxide, hcb, and hchs. unexpectedly, significant pollution of pcbs, ddts, tcpme, and tcpmoh w ...200415025172
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 beneden, 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 specim ...201121451253
detection of multiple budding yeast cells and a partial sequence of 43-kda glycoprotein coding gene of paracoccidioides brasiliensis from a case of lacaziosis in a female pacific white-sided dolphin (lagenorhynchus obliquidens).lacaziosis, formerly called as lobomycosis, is a zoonotic mycosis, caused by lacazia loboi, found in humans and dolphins, and is endemic in the countries on the atlantic ocean, indian ocean and pacific ocean of japanese coast. susceptible cetacean species include the bottlenose dolphin (tursiops truncatus), the indian ocean bottlenose dolphin (t. aduncus), and the estuarine dolphin (sotalia guianensis); however, no cases have been recorded in other cetacean species. we diagnosed a case of lacazi ...201626883513
a characterization of guyana dolphin (sotalia guianensis) whistles from costa rica: the importance of broadband recording systems.knowledge of the whistle structure in guyana dolphins comes mostly from brazilian populations where recordings have been made using limited bandwidth systems (18 and 24 khz). in brazil, guyana dolphin whistle frequency span is 1.34-23.89 khz, but authors have suggested that limits of their recording system may underestimate frequency span. whistles of guyana dolphins from costa rica were studied using a broadband recording system. how bandwidth limitations affect the understanding of whistle str ...200919206893
essential (se, cu) and non-essential (ag, hg, cd) elements: what are their relationships in liver of sotalia guianensis (cetacea, delphinidae)? 200919144361
how marine debris ingestion differs among megafauna species in a tropical coastal area.the marine debris ingested by megafauna species (trichiurus lepturus, chelonia mydas, pontoporia blainvillei, and sotalia guianensis) was recorded in a coastal area of southeastern brazil (21-23°s). marine debris was recorded in all species, mainly consisting of plastic material (flexible and hard plastics - clear, white, and colored- and nylon filaments). the 'pelagic predators' t. lepturus and s. guianesis showed the lowest percent frequencies of debris ingestion (0.7% and 1.3%, respectively), ...201425256299
assessing disease and mortality among small cetaceans stranded at a world heritage site in southern brazil.cetaceans are considered environmental sentinels and their health often reflects either anthropogenic or natural spatio-temporal disturbances. this study investigated the pathological findings and mortality of small cetaceans with the aim of detecting hazards and monitoring health trends in a high-biodiversity area. between 2007 and 2012, 218 stranded cetaceans were recorded on the paraná coast, southern brazil. fifty-seven (26.1%) of these animals, including 50 sotalia guianensis, 2 pontoporia ...201626871703
case report of flipper anatomic anomaly of sotalia guianensis from sepetiba bay, rio de janeiro.the cetacean flipper consists of a soft tissue that encases most of the forelimb containing humerus, radius, ulna, carpals, metacarpals, and phalanges. several studies have documented the typical cetacean's flipper anatomy, but only a few described digital anomalies and the most common are fusions and supernumerary such as polydactily and polyphalangy. the flippers of the guiana dolphin, sotalia guianensis have a falciform general aspect showing individual differences and marks produced by indiv ...201323630189
cetacean diversity on the parnaiba delta, maranhão state, northeastern brazil.the increase in the research of cetacean surveys on the brazilian coast has brought new data on the distribution of species never reported before. the present work reviews the current knowledge on cetaceans species and extends this knowledge with an analysis of cetaceans stranded in the parnaiba delta, on the coast of maranhão state, brazil. the studies on cetacean diversity on the coast of the parnaíba delta were made from august 2004 to august 2006. fourteen strandings were reported, represent ...200818833476
interactions between manta birostris and sotalia guianensis in a world heritage listed brazilian estuary.during 1442 h of visual observations over 7 years throughout the world heritage listed paranaguá estuarine complex, brazil, seven occurrences of interactions were observed at a single location involving breaching manta birostris displacing schools of teleosts, which were subsequently preyed upon by sotalia guianensis. although the interactions were not definitively categorized as being amensal, commensal or mutual, their restriction to isolated space (adjacent to a protected area) and time (summ ...201728804914
toxoplasmosis in a guiana dolphin (sotalia guianensis) from paraná, brazil.this study describes toxoplasmosis in a by caught guiana dolphin (sotalia guinensis) from paranaguá bay, paraná, brazil. interstitial pneumonia, multisystemic arteritis, multifocal adrenalitis and hepatitis were the primary lesions observed. these tissues had moderate to severe necrosis and mononuclear cells infiltration usually surrounded by tachyzoites and tissue cysts. moderate lymphoid depletion was evident in the spleen. toxoplasma gondii was positive by immunohistochemical and ultrastructu ...201323063774
microsatellite loci for population and parentage analysis in the amazon river dolphin (inia geoffrensis de blainville, 1817).we developed specific primers for microsatellite dna regions for the amazon river dolphin or boto inia geoffrensis, for use in population and conservation genetic studies. we also tested their transferability for two other species, pontoporia blainvillei (sister taxon of i. geoffrensis) and sotalia guianensis. a total of 12 microsatellite loci were polymorphic for the boto. an additional 25 microsatellite loci previously isolated from other cetacean species were also tested in the boto. the 26 p ...200921564703
high accumulation of perfluorooctane sulfonate (pfos) in marine tucuxi dolphins (sotalia guianensis) from the brazilian coast.perfluorooctane sulfonate (pfos) and other perfluoroalkyl compounds (pfcs) were measured in liver samples from 29 marine tucuxi dolphins from rio de janeiro state (rj), brazil. pfc measurement combined liquid chromatography and mass spectrometry, using a caplc system connected to a quadrupole-lit mass spectrometer. pfos was the only pfc detected and it was so in all samples. pfos concentrations (ng x g(-1) dw) of dolphins (n=23) from the highly contaminated guanabara bay (in rj) varied between 4 ...200818754395
organochlorine concentrations (pcbs, ddts, hchs, hcb and mirex) in delphinids stranded at the northeastern brazil.organochlorine compounds are highly persistent in the environment, causing bioaccumulation and biomagnification through the marine food chain. to verify the bioaccumulation pattern of ddt and its metabolites, as well as pcbs, mirex, hchs and hcb, samples of subcutaneous adipose tissue from 25 guiana dolphins (sotalia guianensis), two fraser's dolphins (lagenodelphis hosei), two spinner dolphins (stenella longirostris), one spotted dolphin (stenella frontalis), and one striped dolphin (stenella c ...201424291562
population genetic structure of guiana dolphin (sotalia guianensis) from the southwestern atlantic coast of brazil.sotalia guianensis is a small dolphin that is vulnerable to anthropogenic impacts. along the brazilian atlantic coast, this species is threatened with extinction. a prioritized action plan for conservation strategies relies on increased knowledge of the population. the scarcity of studies about genetic diversity and assessments of population structure for this animal have precluded effective action in the region. here, we assessed, for the first time, the genetic differentiation at 14 microsatel ...201728837691
herpesviral infection in a guiana dolphin ( sotalia guianensis) from the northern coast of brazil.we describe herein herpesvirus-associated genital lesions in a guiana dolphin ( sotalia guianensis) from the northern brazilian coast. papillary lesions on the vulva, with epithelial hyperplasia, swollen keratinocytes, and intranuclear inclusions, were positive for a herpesvirus ( gammaherpesvirinae subfamily).201728818026
an assessment of pcb and pbde contamination in two tropical dolphin species from the southeastern brazilian coast.pcbs and pbdes were determined in two dolphin species, sotalia guianensis and steno bredanensis, from an upwelling system off the central-northern coast of rio de janeiro, brazil. pcb levels varied from 0.040 to 0.75 μg g(-1) lw in muscles and from 0.022 to 1.32 μg g(-1)lw in liver samples from s. guianensis. in s. bredanensis, values varied from 0.085 to 11.3 μg g(-1) lw in muscles and from 0.024 to 18.6 μg g(-1) lw in livers. pcb-138, -153 and -180 were the major pcb congeners detected in both ...201526506024
skin diseases in guiana dolphins (sotalia guianensis) from the paranaguá estuary, brazil: a possible indicator of a compromised marine environment.we report on the presence of lobomycosis-like disease (lld) and nodular skin disease (nsd) in a community of guiana dolphins (sotalia guianensis) inhabiting the biologically and chemically contaminated paranaguá estuary (brazil) and on their absence in the community living in the cleaner cananéia estuary. prevalence rates of lld and nsd were 3.9% and 12.6%, respectively, in 103 photo-identified (pi) dolphins from the paranaguá estuary in the period 2006-2007. adults and calves were affected. lob ...200919101029
levels of persistent organic pollutants and residual pattern of ddts in small cetaceans from the coast of são paulo, brazil.the state of são 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 são paulo between 1997 and 2003. ddts (15.9 μg g(-1) lipid; mean for all pooled individuals) and pcbs (8.08 μg g(-1)) exhibited the highest concentrations in ...201020699191
mercury, selenium and stable isotopes in four small cetaceans from the southeastern brazilian coast: influence of feeding strategy.dolphins are good bioindicators of the contamination status of marine ecosystems, since their dietary and habitat plasticity in both coastal and offshore ecotypes provide information on the trace elements levels originated from natural and anthropogenic sources. in this context, this study aimed to investigate provides mercury (hg), selenium (se) levels, trophic ecology and feeding environments of four small cetaceans (tursiops truncatus, steno bredanensis, sotalia guianensis and pontoporia blai ...201627593348
mercury species, selenium, metallothioneins and glutathione in two dolphins from the southeastern brazilian coast: mercury detoxification and physiological differences in diving the present study, the concentration of trace elements, total mercury (hg) and selenium (se) and mercury forms (mehg, hginorg and hgse) in the vulnerable coastal dolphins pontoporia blainvillei and sotalia guianensis were appraised and compared, using metallothioneins (mt) and glutathione (gsh) as biomarkers for trace element exposure. the trace element concentrations varied between muscle and liver tissues, with liver of all dolphin specimens showing higher hg and se concentrations than thos ...201627038210
trophic relationships and habitat preferences of delphinids from the southeastern brazilian coast determined by carbon and nitrogen stable isotope investigate the foraging habitats of delphinids in southeastern brazil, we analyzed stable carbon (δ(13)c) and nitrogen (δ(15)n) isotopes in muscle samples of the following 10 delphinid species: sotalia guianensis, stenella frontalis, tursiops truncatus, steno bredanensis, pseudorca crassidens, delphinus sp., lagenodelphis hosei, stenella attenuata, stenella longirostris and grampus griseus. we also compared the δ(13)c and δ(15)n values among four populations of s. guianensis. variation in ca ...201324358155
social sounds produced by franciscana dolphins, pontoporia blainvillei (cetartiodactyla, pontoporiidae).franciscana dolphin (pontoporia blainvillei) whistles were documented for the first time during 2003-2013 in babitonga bay estuary, south brazil, together with burst pulses. recordings were made from small boats under good sea conditions, and recording equipment that allowed analysis of sounds up to 96 khz. the recordings were made in the presence of 2-31 franciscana dolphins. during 23 h and 53 min, 90 whistles and 51 burst pulse series were recorded. although guiana dolphins (sotalia guianensi ...201728372148
marine debris ingestion by coastal dolphins: what drives differences between sympatric species?this study compared marine debris ingestion of the coastal dolphins pontoporia blainvillei and sotalia guianensis in a sympatric area in atlantic ocean. among the 89 stomach contents samples of p. blainvillei, 14 (15.7%) contained marine debris. for s. guianensis, 77 stomach contents samples were analyzed and only one of which (1.30%) contained marine debris. the debris recovered was plastic material: nylon yarns and flexible plastics. differences in feeding habits between the coastal dolphins w ...201424746357
210polonium content of small cetaceans from southeastern brazil.the (210)po concentration of muscle and liver samples obtained from dolphins stranded on beaches in the southeastern region of rio de janeiro state was analyzed in the present study. the samples were primarily obtained from "franciscana" (pontoporia blainvillei) and "guiana" dolphins (sotalia guianensis); however, samples from four other species were also evaluated. the (210)po concentration of muscle samples obtained from "franciscana" dolphins (66.7±6.7, n=8)bq kg(-1)w.w. was greater than that ...201222304998
pbdes in the blubber of marine mammals from coastal areas of são paulo, brazil, southwestern information is available in the literature on the levels of brominated flame retardants in the southern hemisphere. this study presents concentrations of polybrominated diphenyl ethers (pbdes) in the blubber of small cetaceans from the coast of são paulo (brazil), southwestern atlantic. pbde levels were highest in stenella frontalis (770 ng g(-1) lipid) followed by steno bredanensis (475 ng g(-1) lipid), sotalia guianensis (65.6 ng g(-1) lipid), tursiopstruncatus (64.2 ng g(-1) lipid) an ...201122014918
small cetaceans found stranded or accidentally captured in southeastern brazil: bioindicators of essential and non-essential trace elements in the environment.essential (cu, mn, se and zn) and non-essential (cd and hg) elements were analyzed in the hepatic tissue of 22 individuals of seven different species of small cetaceans (feresa attenuata; orcinus orca; pontoporia blainvillei; sotalia guianensis; stenella frontalis; steno bredanensis; tursiops truncatus) accidentally caught in fishing nets or found stranded along the northern coast of the state of rio de janeiro, brazil, between 2001 and 2010. atlantic spotted dolphin (s. frontalis) showed the hi ...201323993648
ossification pattern of estuarine dolphin (sotalia guianensis) forelimbs, from the coast of the state of espírito santo, brazil.the estuarine dolphin, sotalia guianensis, is one of the most abundant cetacean species in brazil. determination of age and of aspects associated with the development of this species is significant new studies. counts of growth layer groups in dentin are used to estimate age of these animals, though other ways to evaluate development are also adopted, like the measurement of total length (tl). this study presents a procedure to evaluate the development of the estuarine dolphin based on the ossif ...201526017269
high-frequency whistles of guiana dolphins (sotalia guianensis) in guanabara bay, southeastern brazil.guiana dolphins produce whistles with a higher frequency and less complexity than most other delphinid species. the present study used a recording system with sampling rate of 192 khz to describe the high-frequency whistles of sotalia guianensis in guanabara bay, rio de janeiro. eleven acoustic parameters (start, end, minimum, maximum, delta, center and peak frequency, duration, and frequency at 14, 12, and 34 of duration) were measured for all whistles. whistles with a fundamental frequency up ...201525618093
prospective molecular markers for the identification of illegally traded angelsharks (squatina) and dolphin (sotalia guianensis).endangered angelsharks and a protected dolphin species are illegally traded in brazil. in this study, we determined prospective molecular markers for detecting these species in the trade of angelshark carcasses and 'dolphin' eyeball amulets. we compiled publicly available as well as new and unpublished cytochrome b (cyt b) dna sequences for species involved in these trades. these sequences were digested in silico using restriction enzymes. we then described prospective polymerase chain reaction ...201425501182
evidence for signature whistles in guiana dolphins (sotalia guianensis) in ilhéus, northeastern brazil.signature whistles have been widely studied in bottlenose dolphins (tursiops truncatus). a recent study suggested the occurrence of signature whistles in guiana dolphins (sotalia guianensis) but could not identify the whistlers. the objective of this study is to describe the whistle characteristics in the population of s. guianensis from ilhéus and investigate the occurrence of signature whistles. dolphins from 55 groups were photographed and sound emissions from 21 groups were recorded. the fre ...201425480065
fishers' knowledge as a source of information about the estuarine dolphin (sotalia guianensis, van bénéden, 1864).fishers' local ecological knowledge (lek) is an additional tool to obtain information about cetaceans, regarding their local particularities, fishing interactions, and behavior. however, this knowledge could vary in depth of detail according to the level of interaction that fishers have with a specific species. this study investigated differences in small-scale fishers' lek regarding the estuarine dolphin (sotalia guianensis) in three brazilian northeast coastal communities where fishing is prac ...201525399120
radiographic assessment of dental pathology and abnormalities in dolphins.this study proposes a simple standardized method for the production of analog x-ray images of dolphin teeth, and to explore its potential use as a complementary technique in the evaluation of dental pathology in small cetaceans. we investigated exposure times that produced the best results, and whether radiographs helped in the diagnosis of macroscopic abnormalities. teeth of six species of dolphins (delphinidae: tursiops truncatus, steno bredanensis, sotalia guianensis, delphinus sp., stenella ...201728770682
high initial and minimum frequencies of sotalia guianensis whistles in the southeast and south of brazil.recent studies have proposed latitudinal variations for the whistles of sotalia guianensis, since parameters of frequency increase from the southernmost distribution of the species (state of santa catarina, brazil) toward the north. the last study on the whistles of s. guianensis, conducted in costa rica, confirmed the geographical variation of whistles, regardless of frequency responses used in the samples. initial and minimum frequencies of whistles of the costa rican populations were higher t ...201324180798
burst pulses of guiana dolphin (sotalia guianensis) in southeastern brazil.acoustic studies of guiana dolphin have been focused on whistles, with little known about pulse signals in this species. this study characterized the temporal and spectral properties of guiana dolphin burst pulses. groups of 2 to 23 guiana dolphins were recorded while feeding and socializing in shallow waters in guanabara bay, southeastern brazil, in 2013 and 2014. burst pulse analysis involved two steps: signal detection and acoustic parameter analysis. eight variables were analyzed for 197 tot ...201728464652
guiana dolphins (sotalia guianensis) as marine ecosystem sentinels: ecotoxicology and emerging diseases.guiana dolphins (sotalia guianensis) are small cetaceans that inhabit coastal regions down to a 50 m depth. as a coastally distributed species, they are exposed to a variety of human-induced risks that include passive fishing nets, persistent environmental pollution, and emerging diseases. as a top predators. guianensis occupies an important ecological niche in marine ecosystems. however, this niche also exposes this dolphin to extensive biomagnification of marine contaminants that may accumulat ...201424162090
guyana dolphins (sotalia guianensis) from costa rica emit whistles that vary with surface behaviors.guyana dolphins show remarkable intraspecific whistle variation. this variation has been largely explained in terms of distance among populations; however, other factors such as behavior may also be important. a broadband recording system recorded the whistles of guyana dolphins under three behavioral states. a discriminant analysis found that during social and travel events, dolphins emit whistles with high delta and minimum frequency, respectively. whistle duration was also important in discri ...201324116543
lateralized behavior in guiana dolphins, sotalia guianensis, at pipa beach, rn, brazil. 201323644806
passive electroreception in aquatic mammals.passive electroreception is a sensory modality in many aquatic vertebrates, predominantly fishes. using passive electroreception, the animal can detect and analyze electric fields in its environment. most electric fields in the environment are of biogenic origin, often produced by prey items. these electric fields can be relatively strong and can be a highly valuable source of information for a predator, as underlined by the fact that electroreception has evolved multiple times independently. th ...201323187861
variation of age and total length in sotalia guianensis (van bénéden, 1864) (cetacea, delphinidae), on the coast of espírito santo state, brazil.variations of age and total length of sotalia guianensis from the state of espírito santo, brazil, were evaluated. specimens were found stranded. age and total length of 44 guiana dolphins were assessed based on tooth analysis. age varied between 0.5 year and 33 years (mean = 8.23 years). most specimens were between zero and 6 years old (47%). total length varied from 119 cm to 198 cm, with mean of 172.52 cm. asymptotic length was reached at 185 cm and approximately 5-6 years of age. mean total ...201727706394
guiana dolphins (sotalia guianensis) and dr-calux for screening coastal brazilian environments for dioxins and related compounds.guiana dolphin is the top predator of highest toxicological concern in brazil and many studies on levels of persistent, bioaccumulative, and toxicant (pbt) pollutants have been performed on the species. however, due to high costs of the analyses, only one investigation comprised the determination of dioxins and related compounds (drcs) in guiana dolphin tissues. the dioxin responsive-chemically activated luciferase gene expression (dr-calux(®)) cell bioassay was used in the present study for the ...201627430575
whistle comparison of four delphinid species in southeastern brazil.the present study evaluates variations in frequency and duration parameters of whistles of four dolphin species (sotalia guianensis, steno bredanensis, stenella frontalis, and tursiops truncatus), recorded in the rio de janeiro state coast, southeastern brazil. a total of 487 whistles were analyzed. acoustic parameters of the whistles were classified to species by discriminant function analysis. overall classification score was 72.5%, with the highest classification score obtained for whistles o ...201627250196
guiana dolphins (sotalia guianensis, van benédén 1864) as indicators of the bioaccumulation of total mercury along the coast of rio de janeiro state, southeastern mercury (hg) was determined in muscle tissue of 20 guiana dolphins stranded along the coast of rio de janeiro state, brazil, with a mean of 1.07 μg/g wet weight. mercury concentrations were positively related to body length, possibly related to the capacity of the dolphins to bioaccumulate this element throughout life. the hg concentrations were not significantly different between males and females, although females (1.08 μg/g) showed slightly higher levels than males (1.04 μg/g). concentr ...201222057227
population density of sotalia guianensis (cetacea: delphinidae) in the cananéia region, southeastern brazil.population density in cetaceans can be estimated through photo-identification, mark-recapture, land-based observations and visual estimative. we the aim to contribute with conservation strategies, we used line transects (distance method) to estimate the population density of the river dolphin, s. guianensis, in the estuarine region of cananéia, southeastern brazil. the study, developed from may 2003 until april 2004, during dry and rainy seasons and different times of the day, included a samplin ...201122017132
light and scanning electron microscopic study of the tongue in the estuarine dolphin (sotalia guianensis van bénéden, 1864).the importance of the tongue during feeding, and the limited information on the tongue of most aquatic mammals led us to investigate its morphological aspects in sexually immature and mature sotalia guianensis. six tongues were measured and photo-documented after their removal from the oral cavity. the samples were divided into rostral, middle, and caudal regions, and examined using light microscopy and scanning electron microscopy (s.e.m.). sotalia guianensis tongue presented lateral grooves fr ...201121801004
electroreception in the guiana dolphin (sotalia guianensis).passive electroreception is a widespread sense in fishes and amphibians, but in mammals this sensory ability has previously only been shown in monotremes. while the electroreceptors in fish and amphibians evolved from mechanosensory lateral line organs, those of monotremes are based on cutaneous glands innervated by trigeminal nerves. electroreceptors evolved from other structures or in other taxa were unknown to date. here we show that the hairless vibrissal crypts on the rostrum of the guiana ...201221795271
captive-born intergeneric hybrid of a guiana and bottlenose dolphin: sotalia guianensis x tursiops truncatus.bottlenose dolphins (tursiops truncatus) and guiana dolphin (sotalia guianensis) live in sympatry along the caribbean coast of central and south america and social interactions between these species have been described in the caribbean coast of costa rica, including sexual encounters. here we examine and document the only known hybridization event between a male guiana dolphin and a female bottlenose dolphin, in captivity at oceanario islas del rosario (colombian caribbean), using photographic a ...201120033990
possible occurrence of signature whistles in a population of sotalia guianensis (cetacea, delphinidae) living in sepetiba bay, brazil.according to the "signature whistle" hypothesis, dolphins emit stereotypic sequential whistles whose function is to transmit the identity and location of the whistling animal. however, it has also been proposed that the information signature may be expressed by distinct acoustical features within a single type of whistle shared by a population of dolphins. in an attempt to detect signature whistles from sotalia guianensis living in sepetiba bay, rio de janeiro, brazil, 12 h of vocalizations were ...200919739769
mercury-selenium relationships in liver of guiana dolphin: the possible role of kupffer cells in the detoxification process by tiemannite marine predators present high mercury concentrations in their tissues as consequence of biomagnification of the most toxic form of this metal, methylmercury (mehg). the present study concerns mercury accumulation by guiana dolphins (sotalia guianensis), highlighting the selenium-mediated methylmercury detoxification process. liver samples from 19 dolphins incidentally captured within guanabara bay (rio de janeiro state, brazil) from 1994 to 2006 were analyzed for total mercury (thg), methylm ...201222860072
behaviour of sotalia guianensis (van bénéden, 1864) (cetacea, delphinidae) and ethnoecological knowledge of artisanal fishermen from canavieiras, bahia, brazil.artisanal fishermen, because of their direct and frequent contact with the aquatic environment, possess a wealth of knowledge about the natural history of the fauna of the region in which they live. this knowledge, both practical and theoretical, has been frequently utilized and integrated into academic research. taking this into consideration, this study discusses the ethnoecological knowledge of artisanal fishermen from a community in canavieiras, state of bahia, brazil regarding the guiana do ...201222584063
mercury status of the amazon continental shelf: guiana dolphins (sotalia guianensis, van benédén 1864) as a mercury (hg) was analyzed in muscle tissue of 27 accidentally captured guiana dolphins (sotalia guianensis) in order to evaluate hg contamination levels present in the amazon continental shelf, in amapá state, north brazil. the samples showed a mean concentration of 0.4 ± 0.16 μg/g wet weight (ww), ranging from 0.07 to 0.79 μg/g ww. as observed in several other cetacean species, hg concentrations presented positive correlations to body length, related to the capacity to bioaccumulate this ...201222562419
reproductive morphology of female guiana dolphins (sotalia guianensis).the reproductive morphology of cetaceans is poorly studied and, despite the large number of strandings, reports on this subject are scarce due to access to carcasses mostly in an advanced state of decomposition. the present study aimed to describe histological characteristics of the female genital tract of sotalia guianensis, in order to assist in future studies on the reproductive biology of these animals. females of different ages, from stranding events on beaches in northeastern brazil, were ...201526221989
high organochlorine accumulation in blubber of guiana dolphin, sotalia guianensis, from brazilian coast and its use to establish geographical differences among populations.blubber samples from 33 guiana dolphins (sotalia guianensis) from three estuaries (guanabara, sepetiba/ilha grande and paranaguá bays) of southern and southeastern brazil were analyzed for organochlorine compounds (ddts, pcbs and hcb). the sampled individuals were incidentally captured in gillnet fishery between 1995 and 2005. the concentrations (in ng/g lipids) varied from 652 to 23 555 for sigmaddt; from 765 to 99 175 for sigmapcb; and from <4.4 to 156 for hcb. the results have shown that ceta ...201019932538
anthropogenic and naturally-produced organobrominated compounds in marine mammals from brazil.liver samples from 51 cetaceans, comprising 10 species, stranded between 1994 and 2006 in a highly industrialized and urbanized region in southeast brazil, were analyzed for polybrominated diphenyl ethers (pbdes) and methoxylated-pbdes (meo-pbdes). a concentration range of pbdes (3-5960ng/g lw) similar to that observed in northern hemisphere dolphins was found. meo-pbde concentrations in continental shelf (cs) dolphins from brazil are among the highest detected to date in cetaceans (up to 250mic ...201019864024
genetic characterization of anisakis typica and anisakis physeteris from marine mammals and fish from the atlantic ocean off brazil.until now, anisakis typica has been the sole anisakid identified by means of genetic markers from the atlantic ocean off brazil. in this study we developed, and applied to larvae and adults, an a. typica-specific molecular identification protocol based on the complete intergenic transcribed spacer (its) region. anisakids from the dolphin sotalia guianensis and from the frigate tuna, auxis thazard, caught off the coast of brazil, were processed using two dna extraction methods. molecular diagnosi ...200919651475
molecular identification of cetaceans from the west atlantic using the e3-i5 region of coi.molecular identification is very useful in cases where morphology-based species identification is not possible. examples for its application in cetaceans include the identification of carcasses of stranded animals in advanced state of decomposition and body parts that are illegally traded. one dna region that is often used for molecular identification is the folmer region of the mitochondrial gene cytochrome c oxidase subunit i (coi) (locus 48 to 705 bp). this locus has been used for the identif ...201728437554
feeding associations between guiana dolphins, sotalia guianensis (van bénèden, 1864) and seabirds in the lagamar estuary, brazil.the main objective of the present study was to describe the characteristics regarding interactions between guiana dolphins, sotalia guianensis and seabirds in feeding associations in two distinct areas of the lagamar estuary, brazil. boat-based surveys directed towards photo-identification studies of s. guianensis were conducted in the cananéia estuary (ce) (25 degrees 01' s and 47 degrees 55' w) from july 2004 to march 2008, as well as in the paranaguá estuarine complex (pec) (25 degrees 24' s ...201020231955
dental pathology in dolphins (cetacea: delphinidae) from the southern coast of brazil.pathological processes observed in the stomatognathic systems of mammalian species are a useful source of information about the habits, evolution and general health of such animals. studies of pathological conditions on teeth are common in humans and other primates, but rare in wild animals in general and marine mammals in particular. for cetaceans, previous studies provided scanty records of dental anomalies in a few species. this is the first broad and systematic inventory of dental pathology ...201121790069
metazoan parasites of cetaceans off the northeastern coast of brazil.this study represents the first survey of the parasitic fauna of cetaceans off the northeastern coast of brazil. parasites were collected from 82 animals rescued from the states of ceará to bahia, including the archipelago of fernando de noronha. a total of 14 species of cetaceans were evaluated: sotalia guianensis, stenella sp., stenella clymene, stenella longirostris, stenella coeruleoalba, stenella frontalis, megaptera novaeangliae, peponocephala electra, steno bredanensis, kogia breviceps, k ...201020638793
group size and composition of guiana dolphins (sotalia guianensis) (van bénèden, 1864) in the paranaguá estuarine complex, brazil.the aim of the present study was to describe the characteristics of guiana dolphins (s. guianensis) group size and composition in the paranaguá estuarine complex (25 degrees 15'-25 degrees 36' s and 48 degrees 02'-48 degrees 45' w), paraná state, as well as to verify the existence of relationships between a given environmental variable (water depth, salinity, transparency and temperature) and group size. an area of around 124 km(2) was surveyed by boat from april 2006 to february 2008 in the fol ...201020231966
concentration and subcellular distribution of trace elements in liver of small cetaceans incidentally caught along the brazilian coast.concentrations of trace elements (v, cr, mn, fe, co, cu, zn, ga, as, se, rb, sr, mo, ag, cd, sb, cs, ba, t-hg, org-hg, tl and pb) were determined in liver samples of estuarine dolphin (sotalia guianensis; n = 20), franciscana dolphin (pontoporia blainvillei; n = 23), atlantic spotted dolphin (stenella frontalis; n = 2), common dolphin (delphinus capensis; n = 1) and striped dolphin (stenella coeruleoalba; n = 1) incidentally caught along the coast of sao paulo state and parana state, brazil, fro ...200415476836
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