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micro-evolutionary implications of allozymic and morphometric variations in sealworms pseudoterranova sp. (ascaridoidea: anisakidae) among sympatric hosts from the southeastern pacific ocean.we found significant morphometric and electrophoretic differences between sealworm larvae collected from four sympatric fish host species off the central coast of chile. the south american sea lion, otaria byronia, is a suitable host and most likely the only definitive host species in the study area. morphological patterns of caudal papillae in adult males collected from sea lions and electrophoretic evidence from larvae and adults substantiate our conclusion that they belong to just one, new sp ...19958557462
production of chitinase and beta-n-acetylglucosaminidase by intestinal bacteria of pinnipedian animals.the chitinase- and beta-n-acetylglucosaminidase(glcnacase)-producing ability of intestinal bacteria from pinnipedian animals was determined using fluorogenic 4-methylumbelliferone glycosides of n-acetylglucosamine oligosaccharides. intestinal microflora of a single cape fur seal, three california sea lions and three south american sea lions were characterized by a predominance of isolates of the bacteroidaceae and enterobacteriaceae families and the genus clostridium. of the 711 isolates tested ...19968987705
tuberculosis in sea lions and fur seals from the south-western atlantic coast.diverse pathological conditions causing the strandings and/or deaths of several species of sea lions and seals on the northern coast of the province of buenos aires are being studied. tuberculosis was diagnosed in six cases of strandings, involving two otariid seal species (one otaria flavescens and five arctocephalus australis), between march 1989 and december 1992. necropsies were performed on all six cases. granulomatous lesions were observed in the prescapular and hepatic lymph nodes. lesion ...19969025145
molecular characterization of mycobacteria isolated from seals.tuberculosis (tb) was diagnosed in 10 seals from three species (arctocephalus australis, arctocephalus tropicalis and otaria flavescens) found in south america. the mycobacteria isolated from these cases belonged to the mycobacterium tuberculosis complex, as determined by rflp using an is6110 probe, spoligotyping, analysis of the 16s rrna gene sequence and by pcr-restriction analysis of hsp65. polymorphisms in gyra, katg, oxyr and pnca were investigated in some of the isolates, as well as the pr ...199910517604
malassezia pachydermatis isolated from a south american sea lion (otaria byronia) with dermatitis.a fungus was isolated from the skin of an otaria byronia and from the water of the pool in which the animal was kept. it formed creamy colonies with soft texture on dixon agar and grew well without supplements of long-chain fatty acids. cells were ovoid to cylindrical in shape, budded from a broad base, and budded and divided at the same location. thus, the isolate was identified as m. pachydermatis. we compared this very rare isolate from a marine mammal with four strains of m. pachydermatis us ...200010993190
evidence of helicobacter sp. in dental plaque of captive dolphins (tursiops gephyreus).gastrointestinal lesions have been extensively reported in wild and captive marine mammals. however, their etiology remains unclear. in humans and other animals, chronic gastritis and peptic ulcers have been associated with helicobacter sp. therefore, the aim of our study was to investigate the presence of helicobacter sp. in the gastric juice, dental plaque, and saliva of marine mammals living in a controlled environment. five dolphins (tursiops gephyreus), one killer whale (orcinus orca), one ...200212238390
purification and characterization of chitinases from clostridium sp. e-16 isolated from the intestinal tract of the south american sea lion (otaria flavescens).this study was undertaken to examine the properties of chitinases purified from clostridium sp. e-16, an intestinal bacterium of the south american sea lion (otaria flavescens). we also elucidated the taxonomic status of this bacterium to better understand the role of intestinal anaerobic bacteria in marine animals.200616869903
mycobacterium pinnipedii: transmission from south american sea lion (otaria byronia) to bactrian camel (camelus bactrianus bactrianus) and malayan tapirs (tapirus indicus).tuberculosis infections caused by mycobacterium (m.) pinnipedii in a south american sea lion, bactrian camel, and malayan tapirs kept in two zoological gardens spanning a time period of 5 years are reported. the zoos were linked by the transfer of one tapir. conventional bacteriological and molecular methods were applied to detect the pathogen. spoligotyping and miru/vntr-typing performed to assess the genetic similarity revealed identical molecular characteristics of the isolates from all anima ...200817913401
serological evidence of toxoplasma gondii infection in captive marine mammals in mexico.toxoplasma gondii infection in marine mammals is important because they are considered as a sentinel for contamination of seas with t. gondii oocysts, and toxoplasmosis causes mortality in these animals, particularly sea otters. serological evidence of t. gondii infection was determined in 75 captive marine mammals from four facilities in southern and central geographical regions in mexico using the modified agglutination test (mat). antibodies (mat, 1:25 or higher) to t. gondii were found in 55 ...201121944844
mycobacterium pinnipedii in a stranded south american sea lion (otaria byronia) in brazil.we report tuberculosis in a stranded south american sea lion (otaria byronia) in brazil caused by mycobacterium pinnipedii, a member of mycobacterium tuberculosis complex.201424484491
digenetic trematodes in south american sea lions from southern brazilian waters.the aim of this work was to perform a systematic study to detect and quantify the digenetic trematode infections in south american sea lions from the southern brazilian coast. twenty-four south american sea lions, otaria flavescens (carnivora: otaridae), were found dead along the coast of rio grande do sul state, brazil, between june 2010 and september of 2011. two trematode species were found in the intestines of o. flavescens, i.e., stephanoprora uruguayense (digenea: echinostomatidae) and asc ...201323421418
molecular systematics of pinniped hookworms (nematoda: uncinaria): species delimitation, host associations and host-induced morphometric variation.hookworms of the genus uncinaria have been widely reported from juvenile pinnipeds, however investigations of their systematics has been limited, with only two species described, uncinaria lucasi from northern fur seals (callorhinus ursinus) and uncinaria hamiltoni from south american sea lions (otaria flavescens). hookworms were sampled from these hosts and seven additional species including steller sea lions (eumetopias jubatus), california sea lions (zalophus californianus), south american fu ...201324162075
uncinaria hamiltoni (nematoda: ancylostomatidae) in south american sea lions, otaria flavescens, from northern patagonia, argentina.thirty-one south american sea lion pups (otaria flavescens) found dead in punta león, argentina, during the summer of 2002, were examined for hookworms (uncinaria hamiltoni). parasite parameters were analyzed in 2 locations of the rookery, i.e., a traditional, well-structured breeding area and an expanding area with juveniles and a lax social structure. prevalence of hookworms was 50% in both localities, and no difference was observed in prevalence between pup sexes (p > 0.05). hookworms were co ...200415357082
the use of non destructive biomarkers in the study of marine mammals.marine mammals have been subject to heavy anthropogenic pressure by direct killing and chemical pollution all over the world. most studies of contamination and biomarker responses in marine mammals have been conducted using animals killed by hunting out of a total of 12 cetacean species studied, 45 of the specimens were obtained by sacrificing the animal; out of a total of eight pinniped species studied, 40 of the specimens were obtained by killing. the development of a series of non destructive ...199723899212
a new species of ascocotyle (trematoda: heterophyidae) from the south american sea lion, otaria flavescens, off patagonia, argentina.we describe a new heterophyid species, ascocotyle (ascocotyle) patagoniensis n. sp., based on specimens collected from the intestines of the south american sea lion otaria flavescens from patagonia (argentina). ascocotyle (a.) patagoniensis n. sp. is distinguished from the other species of the subgenus by the number of circumoral spines, which are arranged in 2 rows of 18 to 23. the new species also differs from the other species in having a gonotyl without papillae. the specimens exhibited the ...201222375817
assessing host-parasite specificity through coprological analysis: a case study with species of corynosoma (acanthocephala: polymorphidae) from marine mammals.in this paper we report an investigation of the utility of coprological analysis as an alternative technique to study parasite specificity whenever host sampling is problematic; acanthocephalans from marine mammals were used as a model. a total of 252 scats from the south american sea lion, otaria flavescens, and rectal faeces from 43 franciscanas, pontoporia blainvillei, from buenos aires province, were examined for acanthocephalans. specimens of two species, i.e. corynosoma australe and c. cet ...201221554836
morphology of the lingual surface of south american fur seal (arctocephalus australis) and sea lion (otaria flavescens).in this study, we aimed to describe the morphological characteristics of the lingual papillae in two species of otariidae family by stereomicroscopy and scanning electron microscopy. we used tongues of two south american otariidae species. the tongues were elongated and terminated in bifid apex and there was no median sulcus on the dorsal lingual surface. the most numerous type of lingual papilla was filiform in the south american fur seal (sasl) and entire dorsal lingual surface was covered by ...201525431362
intestinal helminth fauna of the south american sea lion otaria flavescens and fur seal arctocephalus australis from northern patagonia, argentina.we report on the intestinal helminth fauna of 56 south american sea lions, otaria flavescens, and 5 south american fur seals, arctocephalus australis, from northern patagonia, argentina. a total of 97,325 helminth specimens were collected from sea lions. gravid individuals were represented by 6 species of parasites: 1 digenean (ascocotyle (ascocotyle) patagoniensis), 1 cestode (diphyllobothrium spp.), 3 nematodes (uncinaria hamiltoni, contracaecum ogmorhini s.s., pseudoterranova cattani) and 1 a ...201322967801
amino acid sequences of hemoglobin beta chains of five species of pinnipeds: neophoca cinerea, otaria byronia, eumetopias jubatus, pusa hispida, and pagophilus groenlandica.pinnipeds (otariidae, odobenidae, and phocidae) in the order carnivora have one or two types (hb i and hb ii) of hemoglobin components. these hemoglobins consist of identical beta chains and different alpha chains. we determined the complete amino acid sequences of the hemoglobin beta chain of three species of otariidae (australian sea lion, south american sea lion, and northern sea lion) and two species of phocidae (ringed seal and harp seal) from intact beta chain and chemical cleavage fragmen ...19968968957
environmental contamination and marine mammals in coastal waters from argentina: an overview.environmental contamination become an increasing global problem. different scientific strategies have been developed in order to assess the impact of pollutants on marine ecosystems. the distribution of toxic contaminants in tissues of different marine mammal species--both cetaceans and pinnipeds--has been studied in many ecosystems, as well as several related ecological processes, like pollutant accumulation or transfer through the food web. a research program directed towards evaluating the oc ...19947973603
longer and less overlapping food webs in anthropogenically disturbed marine ecosystems: confirmations from the past.the human exploitation of marine resources is characterised by the preferential removal of the largest species. although this is expected to modify the structure of food webs, we have a relatively poor understanding of the potential consequences of such alteration. here, we take advantage of a collection of ancient consumer tissues, using stable isotope analysis and siber to assess changes in the structure of coastal marine food webs in the south-western atlantic through the second half of the h ...201425076042
postmortem findings in four south american sea lions (otaria byronia) from an urban colony in valdivia, chile.we performed postmortem examination on four south american sea lions (otaria byronia) from an urban colony in valdivia, chile. chronic leptospirosis and suspected morbillivirus-like infection were diagnosed in one individual. antibodies against toxoplasma gondii and the zoonotic helminthes contracaecum sp., pseudoterranova sp., and diphyllobothrium sp. were also detected.201525380367
coinfection of california sea lion adenovirus 1 and a novel polyomavirus in a hawaiian monk seal (neomonachus schauinslandi).the hawaiian monk seal (neomonachus schauinslandi) is an endangered species. here, we present a clinical case of a 26-yr-old male hawaiian monk seal (hms) kept in an aquarium with a history of intermittent anorexia and evidence of renal disease. histologic examination revealed eosinophilic intranuclear inclusions in the liver. conventional nested pcr protocols were used to test for viruses, and it tested positive for adenovirus and polyomavirus, and negative for herpesvirus. the adenovirus parti ...201627468013
campylobacter insulaenigrae: first isolation report from south american sea lion (otaria flavescens, (shaw, 1800).campylobacter insulaenigrae have been isolated from different pinnipeds but not from south american sea lion (otaria flavescens).the aim of this work is to report the first isolation of c. insulaenigrae from south american sea lion (otaria flavescens).the isolate, identified by its phenotypic and molecular characteristics, allow recognizing o. flavescens as a new host for c. insulaenigrae.201124031630
computed tomographic examination of south american sea lions (otaria flavescens) with suspected mycobacterium pinnipedii infection.ten south american sea lions (otaria flavescens) were presented for clinical evaluation and diagnosis of tuberculosis following known exposure to mycobacterium pinnipedii. ct was used to determine whether foci of calcification in mediastinal lymph nodes, typically associated with pinniped tuberculosis, could be detected and whether ct was a useful diagnostic modality, in conjunction with other tests, for the diagnosis of tuberculosis in this species. blood was collected from the caudal gluteal v ...201121984562
relative quantity judgments in south american sea lions (otaria flavescens).there is accumulating evidence that a variety of species possess quantitative abilities although their cognitive substrate is still unclear. this study is the first to investigate whether sea lions (otaria flavescens), in the absence of training, are able to assess and select the larger of two sets of quantities. in experiment 1, the two sets of quantities were presented simultaneously as whole sets, that is, the subjects could compare them directly. in experiment 2, the two sets of quantities w ...201121526363
thermal reference points as an index for monitoring body temperature in marine mammals.monitoring body temperature is essential in veterinary care as minor variations may indicate dysfunction. rectal temperature is widely used as a proxy for body temperature, but measuring it requires special equipment, training or restraining, and it potentially stresses animals. infrared thermography is an alternative that reduces handling stress, is safer for technicians and works well for untrained animals. this study analysed thermal reference points in five marine mammal species: bottlenose ...201526338544
corrigendum: respiratory function in voluntary participating patagonia sea lions (otaria flavescens) in sternal recumbency.[this corrects the article on p. 528 in vol. 7, pmid: 27899896.].201628070180
description, microhabitat selection and infection patterns of sealworm larvae (pseudoterranova decipiens species complex, nematoda: ascaridoidea) in fishes from patagonia, argentina.third-stage larvae of the pseudoterranova decipiens species complex (also known as sealworms) have been reported in at least 40 marine fish species belonging to 21 families and 10 orders along the south american coast. sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish. however, despite their economic and zoonotic importance, morphological and molecular characterization of species of pseudoterranova in south america is still scarce.201323988009
molecular identification, morphological characterization and new insights into the ecology of larval pseudoterranova cattani in fishes from the argentine coast with its differentiation from the antarctic species, p. decipiens sp. e (nematoda: anisakidae).larvae of the genus pseudoterranova constitute a risk for human health when ingested through raw or undercooked fish. they can provoke pseudoterranovosis in humans, a fish-borne zoonotic disease whose pathogenicity varies with the species involved, making their correct specific identification a necessary step in the knowledge of this zoonosis. larvae of pseudoterranova decipiens s.l. have been reported in several fish species from off the argentine coasts; however, there are no studies dealing w ...201424161261
anthropozoonotic endoparasites in free-ranging "urban" south american sea lions (otaria flavescens).the present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging "urban" colony of south american sea lions (otaria flavescens) living within the city of valdivia, chile. a total of 40 individual faecal samples of south american sea lions were collected during the year 2012 within their natural habitat along the river calle-calle and in the local fish market of valdivia. coprological analyses applying sodium acetate acetic formalin methanol (saf) techniq ...201627051860
lousy mums: patterns of vertical transmission of an amphibious louse.in this study, we document patterns of vertical transmission of the amphibious louse antarctophthirus microchir (echinophthiriidae) in pups of south american sea lion, otaria flavescens, from patagonia. vertical transmission is fundamental for the long-term stability of a. microchir populations because only pups stay long enough (1 month) on land for the louse to reproduce. a total of 72 pups ≤7 days old from a single rookery were captured and examined for lice. infection parameters and populati ...201323828192
an outbreak of lethal adenovirus infection among different otariid species.an outbreak of fatal fulminant hepatitis at a japanese aquarium involved 3 otariids: a california sea lion (zalophus californianus), a south african fur seal (arctocephalus pusillus) and a south american sea lion (otaria flavescens). in a span of about a week in february 2012, 3 otariids showed diarrhea and were acutely low-spirited; subsequently, all three animals died within a period of 3 days. markedly increased aspartate amino transferase and alanine amino transferase activities were observe ...201323643878
respiratory function in voluntary participating patagonia sea lions (otaria flavescens) in sternal recumbency.we measured esophageal pressures (n = 4), respiratory flow rates (n = 5), and expired o2 and co2 (n = 4) in five adult patagonia sea lions (otaria flavescens, body mass range 94.3-286.0 kg) during voluntary breaths while laying down out of water. the data were used to estimate the dynamic specific lung compliance (scl), the o2 consumption rate ([formula: see text]o2) and co2 production rates ([formula: see text]co2) during rest. our results indicate that the resting tidal volume in patagonia sea ...201627899896
long-lasting concentrations of cefovecin after subcutaneous and intramuscular administration to patagonian sea lions (otaria flavescens).cefovecin is a third-generation cephalosporin developed as an aqueous solution for use by the subcutaneous route in dogs and cats. this study evaluated the duration of cefovecin plasma concentrations after single intramuscular (im) or subcutaneous (sc) injection at different doses in 10 patagonian sea lions (otaria flavescens). blood samples were collected serially from the day of the injection up to 60-90 days post-injection. plasma drug concentrations were determined by high performance liquid ...201626639826
anembryonic gestation in wild south american sea lion, otaria flavescens.we present the first record and description of an anembryonic gestation in a wild south america sea lion, otaria flavescens (carnivora, pinniped). this is the first report of an anembryonic gestation in a wild marine mammal species. this description furthers the knowledge of general aspects of the reproduction of an otariid species, which presents the particularities of delayed implantation and polygynic breeding system, and adds information on a reproductive abnormality in marine mammals.201626497953
a case of trychophyton rubrum dermatophytosis in a patagonian sea lion (otaria byronia).a 23-yr old female patagonian sea lion (otaria byronia) presented multifocal to coalescing and ulcerative skin lesions on the lumbar region. skin scrapings were collected and a microscopic examination was conducted followed by a fungal culture that revealed a trychophyton rubrum infection, an anthropophilic dermatophytosis agent. oral terbinafine and topical eniconazole were used as a treatment for a period of 75 days and complete recovery was achieved. epidemiological analysis revealed a dermat ...201526352974
uncovering deep mysteries: the underwater life of an amphibious louse.despite the incredible success of insects in colonizing almost every habitat, they remain virtually absent in one major environment--the open sea. a variety of hypotheses have been raised to explain why just a few insect species are present in the ocean, but none of them appears to be fully explanatory. lice belonging to the family echinophthiriidae are ectoparasites on different species of pinnipeds and river otters, i.e. they have amphibious hosts, who regularly perform long excursions into th ...201425449903
long-term seasonal and interannual patterns of marine mammal strandings in subtropical western south atlantic.understanding temporal patterns of marine mammal occurrence is useful for establishing conservation strategies. we used a 38 yr-long dataset spanning 1976 to 2013 to describe temporal patterns and trends in marine mammal strandings along a subtropical stretch of the east coast of south america. this region is influenced by a transitional zone between tropical and temperate waters and is considered an important fishing ground off brazil. generalized additive models were used to evaluate the tempo ...201626814667
sex beyond species: the first genetically analyzed case of intergeneric fertile hybridization in pinnipeds.a species, according to the biological concept, is a natural group of potentially interbreeding individuals isolated by diverse mechanisms. hybridization is considered the production of offspring resulting from the interbreeding of two genetically distinct taxa. it has been documented in over 10% of wild animals, and at least in 34 cases for artic marine mammals. in otariids, intergeneric hybridization has been reported though neither confirming it through genetic analyses nor presenting evidenc ...201626994861
with the noose around the neck: marine debris entangling otariid species.plastic debris in marine environments and its impact on wildlife species is becoming a problem of increasing concern. in pinnipeds, entanglements commonly consist of loops around the neck of non-biodegradable materials from fishing gear or commercial packaging, known as "neck collars". these entanglements can cause injuries, death by suffocation and starvation, and therefore they may add to the overall decrease in population. our objective was to describe the entanglement of two species of otari ...201727899209
isotopic niche partitioning between two apex predators over time.1.stable isotope analyses have become an important tool in reconstructing diets, analyzing resource use patterns, elucidating trophic relations among predators and understanding the structure of food webs. 2.here, we use stable carbon and nitrogen isotope ratios in bone collagen to reconstruct and compare the isotopic niches of adult south american fur seals (arctocephalus australis; n = 86) and sea lions (otaria flavescens; n = 49) -two otariid species with marked morphological differences- in ...201728326539
sex-specific foraging strategies and resource partitioning in the southern elephant seal (mirounga leonina).the evolution of resource specializations is poorly understood, especially in marine systems. the southern elephant seal (mirounga leonina) is the largest of the phocid seals, sexually dimorphic, and thought to prey predominantly on fish and squid. we collected vibrissae from male and female southern elephant seals, and assessed stable c and n isotope ratios along the length of the vibrissae. given that whiskers grow slowly, this sampling strategy reflects any variation in feeding behaviour over ...200617015314
analysing the natural population growth of a large marine mammal after a depletive harvest.an understanding of the underlying processes and comprehensive history of population growth after a harvest-driven depletion is necessary when assessing the long-term effectiveness of management and conservation strategies. the south american sea lion (sasl), otaria flavescens, is the most conspicuous marine mammal along the south american coasts, where it has been heavily exploited. as a consequence of this exploitation, many of its populations were decimated during the early 20th century but c ...201728706228
adhesive and invasive capacities of edwardsiella tarda isolated from south american sea lion.edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. although e. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. a survey of zoonotic intestinal bacteria in fresh feces from south american sea lions (sasl) otaria flavescens, reported e. tarda as the most frequently isolated species. in this study, we used hep-2 cells to establish in vitro the adherence and invasi ...201425477948
expression and immunohistochemical detection of leptin-like peptide in the gastrointestinal tract of the south american sea lion (otaria flavescens) and the bottlenose dolphin (tursiops truncatus).this study provides an immunohistochemical approach to the expression of leptin in the gastrointestinal tract of the monogastric south american sea lion (otaria flavescens), and the poligastric bottlenose dolphin (tursiops truncatus). the specific organization of the gastrointestinal tract is examined in relation to the neuroendocrine regulation of the gut exerted by leptin. in the south american sea lion some leptin-like-immunoreactive (ir) cells, and endocrine type cells, were found in the pit ...201222791650
ancient female philopatry, asymmetric male gene flow, and synchronous population expansion support the influence of climatic oscillations on the evolution of south american sea lion (otaria flavescens).the south american sea lion (otaria flavescens) is widely distributed along the southern atlantic and pacific coasts of south america with a history of significant commercial exploitation. we aimed to evaluate the population genetic structure and the evolutionary history of south american sea lion along its distribution by analyses of mitochondrial dna (mtdna) and 10 nuclear microsatellites loci. we analyzed 147 sequences of mtdna control region and genotyped 111 individuals of south american se ...201728654647
identification of respiratory and gastrointestinal parasites of three species of pinnipeds (arctocephalus australis, arctocephalus gazella, and otaria flavescens) in southern brazil.in order to improve understanding of parasitism in south american pinnipeds, respiratory and gastrointestinal samples were collected from 12 arctocephalus australis (south american fur seal), one arctocephalus gazella (antarctic fur seal), and one otaria flavescens (south american sea lion). ova and larvae were microscopically identified from fecal samples and respiratory secretions collected from live a. australis undergoing rehabilitation at centro de recuperação de animais marinhos (cram-furg ...201627010274
pinniped tuberculosis in malayan tapirs (tapirus indicus) and its transmission to other terrestrial mammals.in the last 7 yr, three different species of terrestrial mammals were diagnosed with mycobacterium pinnipedii either within one collection or through the introduction of an infected animal from another zoo. the affected species included the malayan tapir (tapirus indicus), bactrian camel (camelus bactrianus bactrianus), and crested porcupine (hystrix cristata). in the first zoo, all of these were living in exhibits adjacent to a group of south american sea lions (otariaflavescens) and were cared ...201122946398
habitat use and spatial fidelity of male south american sea lions during the nonbreeding period.conditions experienced during the nonbreeding period have profound long-term effects on individual fitness and survival. therefore, knowledge of habitat use during the nonbreeding period can provide insights into processes that regulate populations. at the falkland islands, the habitat use of south american sea lions (otaria flavescens) during the nonbreeding period is of particular interest because the population is yet to recover from a catastrophic decline between the mid-1930s and 1965, and ...201728616194
relaxed open mouth reciprocity favours playful contacts in south american sea lions (otaria flavescens).fine-tuning communication is well documented in mammalian social play which relies on a large variety of specific and non-specific signals. facial expressions are one of the most frequent patterns in play communication. the reciprocity of facial signals expressed by the players provides information on their reciprocal attentional state and on the correct perception/decoding of the signal itself. here, for the first time, we explored the relaxed open mouth (rom), a widespread playful facial expre ...201728433401
blood cadmium and metallothionein concentrations in females of two sympatric pinnipeds species.otaria flavescens (sasl) and arctocephalus australis (safs) are endemic of south america. the aims were to assess cd concentrations in red blood cells (rbc) and plasma from free living females of both species; and to establish metallothioneins (mt) levels in blood fractions and the possible relationship between mts and cd. blood of fifteen sasl and eight safs females from isla de lobos were analyzed (years 2010-2011). all animals showed cd levels above the detection limit. cd concentrations on s ...201728576598
a comparison of blood nitric oxide metabolites and hemoglobin functional properties among diving mammals.the ability of marine mammals to hunt prey at depth is known to rely on enhanced oxygen stores and on selective distribution of blood flow, but the molecular mechanisms regulating blood flow and oxygen transport remain unresolved. to investigate the molecular mechanisms that may be important in regulating blood flow, we measured concentration of nitrite and s-nitrosothiols (sno), two metabolites of the vasodilator nitric oxide (no), in the blood of 5 species of marine mammals differing in their ...201727993597
fingerprint of polycyclic aromatic hydrocarbons in two populations of southern sea lions (otaria flavescens).the fingerprint of 14 polycyclic aromatic hydrocarbons (pahs) was investigated in biopsy, fur, blood, liver and faeces of live and dead specimens of two argentinian population of southern sea lion (otaria flavescens). one colony lives in mar del plata harbour which is particularly polluted with petroleum, the second (control) colony lives at punta bermeja (patagonia). the highest concentrations of the five carcinogenic pahs were found in the mar del plata sea lions.19979569942
[helminth parasites of the south american sea lion otaria flavescens from the gulf of arauco, chile]. 20067347613
the helminth fauna of chile: iv. nematodes of the genera anisakis dujardin, 1845 and phocanema myers, 1954 in relation with gastric ulcers in a south american sea lion, otaria byronia.a gastric ulcer was diagnosed in a south american sea lion, otario byronia, captured along the northern coast of chile. species of anisakis and phocanema were found to be associated with the lesions. a discussion of the histopathologic damage observed is presented, along with probable etiology of the ulcer.197616502688
pox in south american sea lions (otaria byronia). 19714326026
regional variability in diving physiology and behavior in a widely distributed air-breathing marine predator, the south american sea lion (otaria byronia).our understanding of how air-breathing marine predators cope with environmental variability is limited by our inadequate knowledge of their ecological and physiological parameters. because of their wide distribution along both coasts of the sub-continent, south american sea lions (otaria byronia) provide a valuable opportunity to study the behavioral and physiological plasticity of a marine predator in different environments. we measured the oxygen stores and diving behavior of south american se ...201627247316
reference intervals of mineral elements in plasma of anesthetized free-ranging adult females of south american sea lion, otaria flavescens.levels of zinc (zn), copper (cu), potassium (k), calcium (ca), magnesium (mg), and phosphorus (p) in plasma of otaria flavescens females (n = 29) were evaluated. reference intervals were established for each element, being the first report for this species.201627156112
gastric carcinoma in a south american sea lion (otaria flavescens).a 22-year-old captive male south american sea lion (otaria flavescens) developed an undifferentiated carcinoma originating in the cardiac region of the stomach. clinical symptoms included vomiting, anorexia and weight loss. ultrasonography and endoscopy showed gastric wall thickness. at necropsy, the gastric wall had significant thickening around the cardiac region, and metastases were found in some organs. histologically, samples from the stomach wall and metastases showed the same tumor tissue ...201627052463
the electrocardiogram of anaesthetized southern sea lion (otaria flavescens) females.the goal of this study was to characterize for the first time the electrocardiogram (ecg) of the southern sea lion (ssl) otaria flavescens.201626644201
diving deeper into individual foraging specializations of a large marine predator, the southern sea lion.despite global declines in the abundance of marine predators, knowledge of foraging ecology, necessary to predict the ecological consequences of large changes in marine predator abundance, remains enigmatic for many species. given that populations suffering severe declines are of conservation concern, we examined the foraging ecology of southern sea lions (ssl) (otaria flavescens)-one of the least studied otariids (fur seal and sea lions)-which have declined by over 90% at the falkland islands s ...201526323982
diet-to-female and female-to-pup isotopic discrimination in south american sea lions.the use of accurate, species-specific diet-tissue discrimination factors is a critical requirement when applying stable isotope mixing models to predict consumer diet composition. thus, diet-to-female and female-to-pup isotopic discrimination factors in several tissues for both captive and wild south american sea lions were estimated to provide appropriate values for quantifying feeding preferences at different timescales in the wild populations of this species.201526212166
occupancy dynamics of south american sea-lions in brazilian haul-outs.along the brazilian coast only two haul-outs of south american sea lions (otaria flavescens) are known: ilha dos lobos and molhe leste, both located in the southernmost state of brazil, rio grande do sul. most sea lions observed in these haul-outs are adult and sub-adult males. it is supposed that the species' presence in these areas is due to food supply and absence of parental assistance by males. this study analysed the use of these haul-outs by o. flavescens between 1993 and 2002 based on co ...201324789403
testing bergmann's rule and the rosenzweig hypothesis with craniometric studies of the south american sea lion.we tested the validity of bergmann's rule and rosenzweig's hypothesis through an analysis of the geographical variation of the skull size of otaria flavescens along the entire distribution range of the species (except brazil). we quantified the sizes of 606 adult south american sea lion skulls measured in seven localities of peru, chile, uruguay, argentina, and the falkland/malvinas islands. geographical and environmental variables included latitude, longitude, and monthly minimum, maximum, and ...201323053224
life begins when the sea lion is ashore: microhabitat use by a louse living on a diving mammal host.among anoplura, the family echinophthiriidae includes species that infest pinnipeds and otters. previous evidence obtained from pinnipeds infested by echinophthiriids, specifically from seals, indicates that flippers are the preferred infestation sites, while lice from fur seals select areas in the pelage. we studied habitat selection of antarctophthirus microchir on south american sea lion pups (otaria flavescens shaw, 1800) from patagonia, argentina, during the austral summer of 2009. we found ...201222244156
mitochondrial control region haplotypes of the south american sea lion otaria flavescens (shaw, 1800).the south american sea lion, otaria flavescens, is widely distributed along the pacific and atlantic coasts of south america. however, along the brazilian coast, there are only two nonbreeding sites for the species (refúgio de vida silvestre da ilha dos lobos and refúgio de vida silvestre do molhe leste da barra do rio grande), both in southern brazil. in this region, the species is continuously under the effect of anthropic activities, mainly those related to environmental contamination with or ...201020838754
ovarian interstitial cell tumor in a south american sea lion (otaria flavescens).a case of an ovarian tumor is reported in an 8-yr-old south american sea lion (otaria flavescens) kept in a marine park in malta (35.57 degrees n, 14.25 degrees e). the neoplasm was a solid mass of dense sheets and nests of round to polyhedral, irregularly shaped cells with abundant, finely vacuolated cytoplasm. the nuclei were uniformly small and round to oval. the supporting stroma contained thecal cells. the tumor cells were positive for positive inhibin and vimentin and focally positive for ...201020688715
population structure and historical demography of south american sea lions provide insights into the catastrophic decline of a marine mammal population.understanding the causes of population decline is crucial for conservation management. we therefore used genetic analysis both to provide baseline data on population structure and to evaluate hypotheses for the catastrophic decline of the south american sea lion (otaria flavescens) at the falkland islands (malvinas) in the south atlantic. we genotyped 259 animals from 23 colonies across the falklands at 281 bp of the mitochondrial hypervariable region and 22 microsatellites. a weak signature of ...201627493782
pup vibrissae stable isotopes reveal geographic differences in adult female southern sea lion habitat use during gestation.individuals within populations often differ substantially in habitat use, the ecological consequences of which can be far reaching. stable isotope analysis provides a convenient and often cost effective means of indirectly assessing the habitat use of individuals that can yield valuable insights into the spatiotemporal distribution of foraging specialisations within a population. here we use the stable isotope ratios of southern sea lion (otaria flavescens) pup vibrissae at the falkland islands, ...201627304855
using satellite tracking and isotopic information to characterize the impact of south american sea lions on salmonid aquaculture in southern chile.apex marine predators alter their foraging behavior in response to spatial and/or seasonal changes in natural prey distribution and abundance. however, few studies have identified the impacts of aquaculture that represents a spatially and temporally predictable and abundant resource on their foraging behavior. using satellite telemetry and stable isotope analysis we examined the degree of spatial overlap between the south american sea lion (sasl) and salmon farms, and quantify the amount of nati ...201526309046
population genetic structure and historical population dynamics of the south american sea lion, otaria flavescens, in north-central patagonia.the north-central patagonian coast is the sea lions most abundant area in argentina. as occurs along the entire atlantic coast, the distribution of breeding colonies at this smaller geographical scale is also patchy, showing at least three areas with breeding activity. we study the genetic structure and historical population dynamics of the species in five colonies in this area, analysing a 508 base-pair segment of the d-loop control region. otaria flavescens showed 10 haplotypes with 12 polymor ...201020526799
organochlorine residues in south american sea lions, otaria flavescens (shaw, 1800): bioaccumulation and time trends.blubber from stranded south american sea lions (otaria flavescens) was sampled between 1991 and 2005 on the peninsula valdés in argentina and analyzed for organochlorine (oc) pollutants. mean blubber concentrations, expressed on an extractable basis, were 686 (sd = 1,060) ng g(-1) for dichlorodiphenyl trichloroethane (tddt) and 735 (sd = 787) ng g(-1) for polychlorinated byphenils (pcb). the oc levels were well below those associated with adverse sublethal effects and lethality in mammals. oc co ...201020458568
redescription of antarctophthirus microchir (anoplura: echinophthiriidae) from the south american sea lion, otaria flavescens, from patagonia, argentina.antarctophthirus microchir was originally described from phocarctos hookeri on the basis of 1 female and 1 male only. we redescribe adults and describe, for the first time, the 3 nymphal stages from specimens collected from otaria flavescens from patagonia, using light and scanning electron microscopy. the present material can be distinguished from other antarctophthirus species by the presence of a fringe of setae on the back of the head, only present in antarctophthirus trichechi and antarctop ...200919463036
population dynamics of antarctophthirus microchir (anoplura: echinophthiriidae) in pups from south american sea lion, otaria flavescens, in northern patagonia.we analysed population dynamics of the louse antarctophthirus microchir in pups of the south american sea lion, otaria flavescens, at the punta león rookery (argentina) over a period of 2 years. a total of 136 pups were aged and marked at the beginning of the lactation period ashore, then sampled for lice at different times within 30 days. sampling was restricted to the chest and belly, two sites where lice were especially abundant. this concentration on ventral areas might protect lice from the ...200919154643
hemangiosarcoma in a south american sea lion (otaria byronia).a 10-yr-old male south american sea lion (otaria byronia) died after several weeks of depression, anorexia, weight loss, and progressive respiratory distress. at necropsy, three confluent, lobulated, dark-red masses were noted in the mesentery. similar masses were also observed in the lung and both kidneys. hemangiosarcoma was diagnosed based on gross findings, histopathology, and immunohistochemistry. this is the first case of hemangiosarcoma reported in pinnipeds.200818432107
sexual harassment and female gregariousness in the south american sea lion, otaria flavescens.most colonial pinnipeds form extreme clusters of breeding females that cannot be entirely explained by the distribution of sites for reproduction. avoidance of male harassment has been postulated as an important determinant of reproductive aggregation in this group of mammals. female gregariousness can reduce harassment by resident males by two mechanisms; directly by the 'dilution effect' or indirectly because resident males that defend large female groups are less harassing. in order to invest ...200818392796
isoflurane anaesthesia in four sea lions (otaria byronia and zalophus californianus).to (1) evaluate a purpose-built chamber for inducing isoflurane anaesthesia in sea lions and (2) assess isoflurane as an anaesthetic for dental surgery in these species.200616916352
[anisakidosis a marine parasitic zoonosis: unknown or emerging in peru?].the purpose of this review is to show the experimental studies carried out on the biological cycle, culture, pathogenicity of the anisakidae nematode larvae and to disseminate the information regarding current epidemy and the probable emergence of anisakidosis in peru, and in addition, to propose measures of prevention and control, as well as the perspective and need for investigation. the studies of experimental pathogenicity in cats, dos, and hamsters are incomplete. eight cases of acute human ...200415614302
2,3,7,8-substituted pcdds and pcdfs in sea lion (otaria flavescens) skin biopsies from two south-western atlantic populations.congener specific 2,3,7,8-chlorinated pcdds and pcdfs were determined in skin biopsies taken from sea lions (otaria flavescens) living in two areas of the south-western atlantic on the coast of argentina (mar del plata and punta bermeja). this is the first report on pcdds and pcdfs in sea lion skin biopsies from the southern hemisphere. differences were found in the congener pattern according to the sampling area. animals living in the polluted area (mar del plata harbour) had detectable levels ...199910901670
skin biopsy as a nondestructive tool for the toxicological assessment of endangered populations of pinnipeds: preliminary results on mixed function oxidase in otaria flavescens.the aim of this study was to develop and validate a method for assessing the toxicological risk of endangered populations of pinnipeds based on a nondestructive biological tool, the skin biopsy specimen. skin biopsies can be obtained from pinnipeds by anaesthetising the animals and taking a small amount of skin in the anterior flipper area, or by shooting a biopsy dart with a crossbow. skin biopsy material is suitable for a wide range of chemical and biomarker analysis. organochlorines and polyc ...19979353903
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