Publications

initial evidence for adaptive selection on the nadh subunit two of freshwater dolphins by analyses of mitochondrial genomes.	a small number of cetaceans have adapted to an entirely freshwater environment, having colonized rivers in asia and south america from an ancestral origin in the marine environment. this includes the 'river dolphins', early divergence from the odontocete lineage, and two species of true dolphins (family delphinidae). successful adaptation to the freshwater environment may have required increased demands in energy involved in processes such as the mitochondrial osmotic balance. for this reason, r ...	2015	25946045
acoustic characteristics of biosonar sounds of free-ranging botos (inia geoffrensis) and tucuxis (sotalia fluviatilis) in the negro river, amazon, brazil.	odontoceti emit broadband high-frequency clicks on echolocation for orientation or prey detection. in the amazon basin, two odontoceti species, boto (amazon river dolphin, inia geoffrensis) and tucuxi (sotalia fluviatilis), live sympatrically. the acoustic characteristics of the echolocation clicks of free-ranging botos and tucuxis were measured with a hydrophone array consisting of a full-band and an acoustic event recorder (a-tag). the clicks of the two species were short-duration broadband si ...	2015	26328686
when you get what you haven't paid for: molecular identification of "douradinha" fish fillets can help end the illegal use of river dolphins as bait in brazil.	the fishery for calophysus macropterus, an amazonian necrophagous catfish, is highly detrimental to river dolphins and caimans, which are deliberately killed for use as bait. in the brazilian amazon, this fishery has increased over the last decade, in spite of the rejection of scavenger fishes by brazilian consumers. it was suspected that c. macropterus fillets were being sold in brazilian markets, disguised as a fictitious fish (the "douradinha"). we collected 62 fillets from "douradinha" and o ...	2015	26245791
purification and characterization of a liver-derived beta-n-acetylhexosaminidase from marine mammal sotalia fluviatilis.	a beta-n-acetylhexosaminidase (ec 3.2.1.52) was purified from hepatic extracts of sotalia fluviatilis, order cetacea. the protein was purified by using ammonium sulfate fractionation and four subsequent chromatographies (biogel a 1.5 m, chitin, deae-biogel and hydroxyapatite resins). after these purification steps, the enzyme was purified 380.5-fold with an 8.4% yield. the molecular mass (10 kda) was estimated by sds-page and maldi-tof analysis. a km of 2.72 mm and vmax 9.5 x 10(-6) micromol/(mi ...	2010	20349205
the freshwater dolphin inia geoffrensis geoffrensis produces high frequency whistles.	because whistles are most commonly associated with social delphinids, they have been largely overlooked, ignored, or presumed absent, in solitary freshwater dolphin species. whistle production in the freshwater dolphin, the boto (inia geoffrensis geoffrensis), has been controversial. because of its sympatry with tucuxi dolphins (sotalia fluviatilis), a whistling species, some presume tucuxi whistles might have been erroneously assigned to the boto. using a broadband recording system, we recorded ...	2007	17348541
placentation in dolphins from the amazon river basin: the boto, inia geoffrensis, and the tucuxi, sotalia fluviatilis.	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. t ...	2007	17597550
sensitivity of a tucuxi (sotalia fluviatilis guianensis) to airborne sound.	auditory systems of cetaceans are considered highly specialized for underwater sound processing, whereas the extent of their hearing capacity in air is still a point of issue. in this study, the sensitivity to airborne sound in a male tucuxi (sotalia fluviatilis guianensis) was tested by means of a go/no go response paradigm. auditory thresholds were obtained from 2 to 31.5 khz. compared to the hearing thresholds of other dolphins as well as of amphibian mammals, the sensitivity to airborne soun ...	2005	15704436
whistles of tucuxi dolphins (sotalia fluviatilis) in brazil: comparisons among populations.	a quantitative and comparative analysis of the acoustic whistles parameters of tucuxi dolphins (sotalia fluviatilis) from eight areas in brazilian waters were conducted. tucuxi produced mainly upsweep whistles, and despite their similar characteristics to other delphinids, whistles were shorter and less complex in shape. some signals had fundamental frequency components above 24 khz, and a broader band system may be useful in further studies concerning tucuxi whistles. the frequency parameters o ...	2005	15807033
whistles of small groups of sotalia fluviatilis during foraging behavior in southeastern brazil.	whistle emissions were recorded from small groups of marine tucuxi dolphins (sotalia fluviatilis) in two beaches located in an important biological reserve in the cananéia estuary (25 degrees 03's, 47 degrees 58'w), southeastern brazil. a total of 17 h of acoustic data was collected when dolphins were engaged in a specific feeding foraging activity. the amount of 3235 whistles was recorded and 40% (n=1294) were analyzed. seven acoustic whistle parameters were determined: duration (ms), number of ...	2005	16266192
analysis of whistles produced by the tucuxi dolphin sotalia fluviatilis from sepetiba bay, brazil.	from july 2001 to june 2002, we recorded a total of 2 h 55 min of tucuxi dolphin sotalia fluviatilis vocalizations from sepetiba bay, brazil (22 degrees 35's-44 degrees 03'w). a total of 3350 whistles were analyzed quantitative and qualitatively and were divided into 124 types, by visual inspection of sonograms. the following parameters were measured: initial frequency, final frequency, minimum frequency, maximum frequency, duration, number of inflections, frequency at the inflection points, fre ...	2004	15258654
concentrations of heavy metals in sotalia fluviatilis (cetacea: delphinidae) off the coast of ceará, northeast brazil.	lead (pb), cadmium (cd) and mercury (hg) concentrations on liver and kidney of sotalia fluviatilis (cetacea: delphinidae) stranded in the coast of ceará, brazil, were studied from 1996 to 1999. pb levels were usually lower than the detection limit (0.1 microg/g). concentrations of cd were significantly higher in kidney than liver, averaging 0.8 microg/g. mercury accumulation took place mainly in liver with an average concentration of 4.6 microg/g. both metals were significantly higher in larger ...	2003	12628211
chlorinated pesticides and polychlorinated biphenyls in marine tucuxi dolphins (sotalia fluviatilis) from the cananéia estuary, southeastern brazil.	the cananéia estuary is an important biological area on the southeast coast of brazil. in the past, it was impacted by both chlorinated pesticides and polychlorinated biphenyls (pcbs) due to its natural location. the marine tucuxi dolphin (sotalia fluviatilis) is a top predator in this ecosystem and can be found year round in cananéia estuarine waters that represent an important nursing area for the species. this work investigated chlorinated compounds in the blubber of nine individuals from the ...	2003	12873400
genetic markers in the study of anisakis typica (diesing, 1860): larval identification and genetic relationships with other species of anisakis dujardin, 1845 (nematoda: anisakidae).	genetic variation at 21 gene-enzyme systems was studied in a sample of an adult population of anisakis typica (diesing, 1860) recovered in the dolphin sotalia fluviatilis from the atlantic coast of brazil. the characteristic alleles, detected in this population, made it possible to identify as a. typica, anisakis larvae with a type i morphology (sensu berland, 1961) from various fishes: thunnus thynnus and auxis thazard from brazil waters, trachurus picturatus and scomber japonicus from madeiran ...	2002	11912342
whistles of boto, inia geoffrensis, and tucuxi, sotalia fluviatilis.	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 fr ...	2001	11206170
selective heating of vibrissal follicles in seals (phoca vitulina) and dolphins (sotalia fluviatilis guianensis).	the thermal characteristics of the mystacial vibrissae of harbour seals (phoca vitulina) and of the follicle crypts on the rostrum of the dolphin sotalia fluviatilis guianensis were measured using an infrared imaging system. thermograms demonstrate that, in both species, single vibrissal follicles are clearly defined units of high thermal radiation, indicating a separate blood supply to these cutaneous structures. it is suggested that the high surface temperatures measured in the area of the mou ...	2000	10862725
relationship between dental morphology, sex, body length and age in pontoporia blainvillei and sotalia fluviatilis (cetacea) in northern rio de janeiro, brazil.	the relationship between dental morphology, sex, body length and age of small cetaceans can be used to determine ontogeny, sexual dimorphism and geographical variation. the objective of this study was to determine the relationship between dental morphology, sex, body size and age. a total of 91 specimens of p. blainvillei and 80 specimens of s. fluviatilis accidentally captured in fisheries or stranded in northern rio de janeiro (21 masculine37'-22 masculine25's), from september 1988 to november ...	2000	10959112
underwater audiogram of a tucuxi (sotalia fluviatilis guianensis).	using a go/no go response paradigm, a tucuxi (sotalia fluviatilis guianensis) was trained to respond to pure-tone signals for an underwater hearing test. auditory thresholds were obtained from 4 to 135 khz. the audiogram curve shows that this sotalia had an upper limit of hearing at 135 khz; from 125 to 135 khz sensitivity decreased by 475 db/oct. this coincides with results from electrophysiological threshold measurements. the range of best hearing (defined as 10 db from maximum sensitivity) wa ...	1998	9479772
lipids of freshwater dolphin sotalia fluviatilis: comparison of odontocete bioacoustic lipids and habitat.	the melon and jaw lipids of the freshwater dolphin sotalia fluviatilis are composed mainly of isovaleroyl wax esters and diisovaleroyl triglycerides. the blubber fat contains only a trace of wax ester and is mostly tri-(long chain) and monoisovaleroyl triglycerides. detailed gas liquid chromatographic analyses of the intact wax esters and triglycerides and of the derived fatty acids and fatty alcohols indicate common compositional patterns in the wax esters and triglycerides of the respective he ...	1975	1123975
the gonads of the south american dolphins, inia geoffrensis, pontoporia blainvillei, and sotalia fluviatilis.		1971	5581374