| 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 ... | 1996 | 9025145 |
| 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 ... | 1999 | 10517604 |
| 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 ... | 2002 | 12238390 |
| [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 ... | 2004 | 15614302 |
| corynosoma australe johnston, 1937 and c. cetaceum johnston & best, 1942 (acanthocephala: polymorphidae) from marine mammals and fishes in argentinian waters: allozyme markers and taxonomic status. | genetic and morphological studies were carried out on acanthocephalans belonging to corynosoma lühe, 1904 and referable to the species c. cetaceum johnston & best, 1942 and c. australe johnston, 1937, which were recovered from both definitive and intermediate hosts in argentinian waters. the aims were to estimate the level of genetic differentiation between the two taxa at any stage of their life-cycle, to provide genetic (allozyme) markers for their recognition and to analyse the systematic sta ... | 2005 | 15980967 |
| gross heart anatomy of arctocephalus australis (zimmerman, 1783). | little research has been carried out on the gross visceral anatomy of the otariidae, and the anatomical information for the southern fur seals, arctocephalus spp., is scant. the aim of the present study was to describe the external and internal conformation, and the sanguineous irrigation of the heart of arctocephalus australis. twelve hearts of arctocephalus australis were studied by simple dissection. in the right ventricle the trabeculae carneae were well developed and there were three or mor ... | 2008 | 18402082 |
| helicobacter spp. from gastric biopsies of stranded south american fur seals (arctocephalus australis). | gastrointestinal lesions with uncertain etiology have been widely described among pinnipeds. the aim of our study was to investigate the presence of helicobacter spp. in the gastric mucosa of south american fur seals (arctocephalusaustralis). gastric biopsies from thirteen seals, stranded on the shores of the southwestern atlantic ocean in argentina, were evaluated for the presence of helicobacter spp. by pcr and dna sequence analysis. six gastric biopsies were positive for helicobacter spp. pai ... | 2009 | 18504051 |
| serologic evidence of influenza a and b viruses in south american fur seals (arctocephalus australis). | the aim of this work was to detect serologic evidence of influenza virus infections in south american fur seals (arctocephalus australis) that inhabit the uruguayan coast. in 29 of 37 serum samples that were analyzed, we identified antibodies to at least one of the following antigens: h1n1 (a/newcaledonia/20/99), b/beijing/184/93-like viruses, b/hong kong/330/01, and b/sichuan/379/99 by means of the hemagglutination inhibition assay (hai). results confirmed that influenza a viruses circulate in ... | 2009 | 19395764 |
| 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 ... | 2016 | 27010274 |
| survey for infectious disease in the south american fur seal (arctocephalus australis) population at punta san juan, peru. | the peruvian population of the south american fur seal ( arctocephalus australis ) is a distinct evolutionarily significant unit that is endangered. one of the largest rookeries for this species in peru is located within the punta san juan marine protected area (15°22's, 75°12'w). to better understand the current health status of this population, exposure to 10 pinniped pathogens was evaluated in adult female fur seals (n=29) via serology and polymerase chain reaction (pcr) techniques in novembe ... | 2015 | 26056875 |
| 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 ... | 2013 | 22967801 |
| enterococcus species diversity in fecal samples of wild marine species as determined by real-time pcr. | analyses using culture-independent molecular techniques have improved our understanding of microbial composition. the aim of this work was to identify and quantify enterococci in fecal samples of wild marine species using real-time quantitative pcr. seven enterococcus species were examined in fecal dna of south american fur seals (arctocephalus australis), subantarctic fur seals (arctocephalus tropicalis), green turtles (chelonia mydas), magellanic penguins (spheniscus magellanicus), snowy-crown ... | 2017 | 27991828 |
| antimicrobial resistance and virulence factor gene profiles of enterococcus spp. isolates from wild arctocephalus australis (south american fur seal) and arctocephalus tropicalis (subantarctic fur seal). | enterococci are natural inhabitants of the gastrointestinal tracts in humans and animals. epidemiological data suggest that enterococci are important reservoirs of antimicrobial resistant genes that may be transmitted from other bacterial species the aim of this study was to investigate the species composition, antimicrobial resistance and virulence genes in enterococci recovered from fecal samples of wild arctocephalus australis and a. tropicalis found dead along the south coast of brazil. from ... | 2015 | 26347323 |
| 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 ... | 2013 | 24162075 |
| 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 ... | 2017 | 28326539 |
| hookworm infection in south american fur seal ( arctocephalus australis) pups. | tissues of south american fur seal pups naturally infected with hookworms ( uncinaria sp) were examined. hookworm infection was found in nearly all pups examined (132/140, 94%), and hookworm enteritis with secondary bacteremia was considered the cause of death in 46 (35%) pups. common findings in these pups included severe hemorrhagic enteritis and numerous (mean intensity = 761.8) hookworms in the jejunum. hookworms were recovered from the abdominal cavity in 12 of 55 pups (22%) examined throug ... | 2017 | 28207376 |
| holocene changes in the trophic ecology of an apex marine predator in the south atlantic ocean. | predators may modify their diets as a result of both anthropogenic and natural environmental changes. stable isotope ratios of nitrogen and carbon in bone collagen have been used to reconstruct the foraging ecology of south american fur seals (arctocephalus australis) in the southwestern south atlantic ocean since the middle holocene, a region inhabited by hunter-gatherers by millennia and modified by two centuries of whaling, sealing and fishing. results suggest that the isotopic niche of fur s ... | 2017 | 27900469 |
| 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 ... | 2017 | 27899209 |
| molecular detection of circovirus and adenovirus in feces of fur seals (arctocephalus spp.). | in some regions, little is known about exposure to viruses in coastal marine mammals. the present study aimed to detect viral rna or dna in 23 free-ranging fur seals on the northern coastline of rio grande do sul state, brazil. polymerase chain reaction was used to detect nucleic acids of circoviruses, adenoviruses, morbilliviruses, vesiviruses, and coronaviruses in the feces from twenty-one south american fur seals (arctocephalus australis) and two subantarctic fur seals (a. tropicalis). adenov ... | 2017 | 27803979 |
| hematology, serum chemistry, and early hematologic changes in free-ranging south american fur seals ( arctocephalus australis ) at guafo island, chilean patagonia. | the establishment of clinical pathology baseline data is critical to evaluate temporal and spatial changes in marine mammal groups. despite increased availability of studies on hematology and biochemistry of marine mammals, reference ranges are lacking for many populations, especially among fur seal species. during the austral summers of 2014 and 2015, we evaluated basic hematologic and biochemical parameters in clinically healthy, physically restrained south american fur seal ( arctocephalus au ... | 2016 | 27243331 |
| 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 ... | 2016 | 26994861 |
| metagenomic survey of viral diversity obtained from feces of subantarctic and south american fur seals. | the brazilian south coast seasonally hosts numerous marine species, observed particularly during winter months. some animals, including fur seals, are found dead or debilitated along the shore and may harbor potential pathogens within their microbiota. in the present study, a metagenomic approach was performed to evaluate the viral diversity in feces of fur seals found deceased along the coast of the state of rio grande do sul. the fecal virome of two fur seal species was characterized: the sout ... | 2016 | 26986573 |
| characterization of the faecal bacterial community of wild young south american (arctocephalus australis) and subantarctic fur seals (arctocephalus tropicalis). | the microbiota of wild marine mammals is poorly understood, perhaps due to the migratory habits of some species and the difficulty in obtaining samples. using high-throughput sequencing, the present study examines the faecal bacterial community of wild young south american (arctocephalus australis) and subantarctic fur seals (a. tropicalis). faecal samples from south american (n = 6) and subantarctic fur seals (n = 4) found dead along the south coast of brazil were collected. sequences were assi ... | 2016 | 26880785 |
| a novel gammaherpesvirus in northern fur seals (callorhinus ursinus) is closely related to the california sea lion (zalophus californianus) carcinoma-associated otarine herpesvirus-1. | otarine herpesvirus 1 (othv1) is strongly associated with california sea lion (csl, zalophus californianus) urogenital carcinoma, the most common cancer documented in marine mammals. in addition to csl, othv1 has also been found in association with carcinoma in south american fur seals (arctocephalus australis), demonstrating it can infect related species. northern fur seals (nfs, callorhinus ursinus) are sympatric with csl, and copulation between these species has been observed; yet, there are ... | 2016 | 26555110 |
| death of a south american fur seal (arctocephalus australis) after the ingestion of toads--evaluation of toad poisoning by toxicological analysis. | animals in zoological gardens are at risk of severe and even lethal poisoning when they accidentally ingest toads. here we report the case of an eleven month old male south american fur seal (arctocephalus australis) which was found dead in its outdoor enclosure in the zoo of dortmund, germany. autopsy revealed the presence of two adult, partly digested common toads (bufo bufo) in the stomach. toxicological analysis of the stomach content using high performance liquid chromatography coupled to t ... | 2015 | 26054232 |
| 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 ... | 2015 | 25431362 |
| histological patterns of the intestinal attachment of corynosoma australe (acanthocephala: polymorphidae) in arctocephalus australis (mammalia: pinnipedia). | the mucosal attachment pattern of corynosoma australe in the intestines of arctocephalus australis is described. normal and abnormal tissue were sampled from 32 hosts to be submitted to histological routine protocol to embedding in paraffin and permanent mounting in balsam. corynosoma australe shows three different degrees of body depth intestinal attachment (bdina-1-3). bdina-1: it is exclusive of the small intestine and the parasite attaches on the villi; bdina-2: parasite affects the lieberkü ... | 2014 | 25320494 |
| encephalitozoonosis in 2 south american fur seal (arctocephalus australis) pups. | cerebral and disseminated encephalitozoonosis was diagnosed by histopathology, electron microscopy, and immunohistochemistry in 2 free-ranging south american fur seal pups found dead at guafo island (43°33's 74°49'w) in southern chile. in the brain, lesions were characterized by random foci of necrosis with large numbers of macrophages containing numerous microsporidial organisms within parasitophorous vacuoles. in addition, occasional histiocytes loaded with numerous mature and immature microsp ... | 2015 | 25248519 |
| 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 ... | 2014 | 25076042 |
| relating diving behavior and antioxidant status: insights from oxidative stress biomarkers in the blood of two distinct divers, mirounga leonina and arctocephalus australis. | pinnipeds rely upon diving to perform essential activities, including foraging. as pulmonated animals, oxygen privation experienced during submergence represents a considerable challenge both physiologically and biochemically. routine exposure to hypoxia and the rapid transitions between ischemia/reperfusion of tissues leads to extremely high reactive oxygen species (ros) production, which must be opposed by antioxidant defenses to avoid oxidative stress. the diving behaviors and capabilities of ... | 2014 | 24607367 |
| resting metabolic rate and heat increment of feeding in juvenile south american fur seals (arctocephalus australis). | bio-energetic models used to characterize an animal's energy budget require the accurate estimate of different variables such as the resting metabolic rate (rmr) and the heat increment of feeding (hif). in this study, we estimated the in air rmr of wild juvenile south american fur seals (safs; arctocephalus australis) temporarily held in captivity by measuring oxygen consumption while at rest in a postabsorptive condition. hif, which is an increase in metabolic rate associated with digestion, as ... | 2014 | 24269958 |
| anomalous colour in neotropical mammals: a review with new records for didelphis sp. (didelphidae, didelphimorphia) and arctocephalus australis (otariidae, carnivora). | anomalous colourations occur in many tropical vertebrates. however, they are considered rare in wild populations, with very few records for the majority of animal taxa. we report two new cases of anomalous colouration in mammals. additionally, we compiled all published cases about anomalous pigmentation registered in neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. every record was classified as albinism, leucism, piebaldism or eventually as ... | 2013 | 23644801 |
| the first report of otarine herpesvirus-1-associated urogenital carcinoma in a south american fur seal (arctocephalus australis). | otarine herpesvirus (othv)-1-associated urogenital carcinoma has been well documented in the california sea lion (zalophus californianus, csl), but this is the first report of this tumour in a captive south american fur seal (arctocephalus australis, safs). the gross and microscopical morphology of the tumour in the safs was identical to that described previously in csls and the tumour in the present case had metastasized within the urogenital tract and draining lymph nodes and to the lungs and ... | 2013 | 23218410 |
| pathological findings in south american fur seal pups (arctocephalus australis gracilis) found dead at guafo island, chile. | during four breeding seasons (2004-2008), 78 necropsy examinations were performed on south american fur seal pups (arctocephalus australis gracilis) found dead on guafo island, southern chile (43°36's, 74°43'w). tissue samples from 65 pups were examined microscopically. the primary causes of death were enteritis with microscopical lesions of bacteraemia (28.2%), starvation (23.1%), drowning (21.8%), trauma (19.2%) and stillbirth (2.6%). those pups with enteritis and microscopical lesions of bact ... | 2011 | 21396659 |
| histomorphology of prepuberal ovaries in the south american fur seal (arctocephalus australis zimmerman, 1783). | the south american fur seal reproductive histophysiology is scarcely described. this study provides a histological description of prepuberal south american fur seal (arctocephalus australis) ovaries as well as three-dimensional reconstructions of subcapsular crypts and primordial follicles. ovaries from fresh dead animals were processed for histology and sliced into serial sections. a portion of the superficial cortex was photographed, and the images were processed using biovis3d software in ord ... | 2009 | 19950080 |
| trace metal concentration in liver, kidney and heart in south american fur seal (arctocephalus australis) from southern brazil. | | 2009 | 19931872 |
| accumulation patterns of organochlorines in juveniles of arctocephalus australis found stranded along the coast of southern brazil. | the present study was conducted to elucidate the specific distributions of organochlorine (oc) compounds in various tissues and organs of juveniles of the south american fur seal (arctocephalus australis) found stranded on beaches in southern brazil. the oc residue concentrations occurred in the following order: pcbs>ddts>chls>hchs>hcb. oc concentrations in blubber were higher than other tissues (e.g. pcbs, 2480 ng g(-1) wet weight; ddts, 660 ng g(-1) wet weight) indicating a positive associatio ... | 2007 | 17029680 |
| ultrastructure of proechinophthirus zumpti (anoplura, echinophthiriidae) by scanning electron microscopy. | the ultrastructure of proechinophthirus zumpti werneck, 1955, mainly the external chorionic features of the egg, is described through electronic microscopy techniques. this species was first cited in argentina, infesting arctocephalus australis (zimmermann, 1873). the morphological adaptations of adults and nymphs are described in both species of proechinophthirus parasitic on otariidae: p. fluctus (ferris, 1916) and p. zumpti. | 2002 | 12386702 |
| behavioural responses of south american fur seals to approach by tourists - a brief report. | i studied the responses (retreats, threats, attacks or leaving the rookery) of south american fur seals arctocephalus australis to tourist approaches at a non-reproductive, continental colony of located in cabo polonio, uruguay (34 degrees 24's, 53 degrees 46'w). fur seals tolerated relatively close distances to humans, but a strong response of the animals was elicited when tourists crossed a threshold of 10m. the attitude of the tourist was also important. calm people were able to approach the ... | 2001 | 11248383 |
| mitotic and meiotic analysis in arctocephalus australis (otariidae). | the karyotype with c-, g- and nor-banding of arctocephalus australis is reported for the first time. the chromosomal number is 2n = 36. the x chromosome, identified in g-banded metaphases from males, is metacentric and the y chromosome is a minute chromosome, also metacentric. pachytene spermatocytes were used for synaptonemal complexes analysis with a surface spreading technique. a total of 17 autosomal synaptonemal complexes are observed plus the xy pair. during early pachytene, the x and y ax ... | 1999 | 10628295 |
| 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 ... | 1994 | 7973603 |
| [the respiratory system in arctocephalus australis (pinnipedia, otariidae). i--macroanatomy and microanatomy of the trachea and extrapulmonary airways]. | this paper presents the results of histological and histochemical organization of trachea and primary bronchi. the presence of a subepithelial lamina and a smooth muscle layer in the superficial corion, probably related with a functional respiratory mechanism are defined. the structure of tracheal and primary bronchi glands, the way they secretes and the type of secretion are also described. | 1991 | 1844100 |
| kelp and dolphin gulls cause perineal wounds in south american fur seal pups (arctocephalus australis) at guafo island, chilean patagonia. | during five reproductive seasons, we documented the presence, extent and origin of perineal wounds in south american fur seal pups (arctocephalus australis) on guafo island, northern chilean patagonia. the seasonal prevalence of perineal wounds ranged from 5 to 9%, and new cases were more common at the end of the breeding season (february), when pups were on average two months old and were actively expelling hookworms (uncinaria sp). histologically, wounds corresponded to marked ulcerative lymph ... | 2017 | 28791178 |
| how animals distribute themselves in space: variable energy landscapes. | foraging efficiency determines whether animals will be able to raise healthy broods, maintain their own condition, avoid predators and ultimately increase their fitness. using accelerometers and gps loggers, features of the habitat and the way animals deal with variable conditions can be translated into energetic costs of movement, which, in turn, can be translated to energy landscapes.we investigated energy landscapes in gentoo penguins pygoscelis papua from two colonies at new island, falkland ... | 2017 | 28694838 |
| 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 ... | 2016 | 26814667 |
| marine debris ingestion by the south american fur seal from the southwest atlantic ocean. | in this paper, we examined the ingestion of marine debris (md) in south american fur seals (safs), arctocephalus australis, found dead in coastal beaches of northern argentina and southern brazil. seven percent of 133 safs analyzed presented marine debris in their stomach (n=10), with no differences between sampling countries (brazil n=7, argentina n=3) and sexes (female=3; male=6). however, significant differences were observed between ages classes, with md exclusively present in stomach conten ... | 2017 | 28693811 |
| 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 ... | 2017 | 28576598 |
| reproductive tract histology in south american fur seal pups (arctophoca australis). | in the present study, a detailed histological description of the female reproductive tract of south american fur seal (arctophoca australis) pups has been conducted. the uterine tube was covered by cuboidal to columnar epithelium; nerve fibers were present in the mesosalpinx and beneath the muscular layer. the uterus was bipartitus; the endometrial surface of the horns was lined by a simple cuboidal or columnar epithelium with deep tubular glands; caudally ("the transition area"), the epithelium ... | 2017 | 27981794 |
| bias in diet determination: incorporating traditional methods in bayesian mixing models. | there are not "universal methods" to determine diet composition of predators. most traditional methods are biased because of their reliance on differential digestibility and the recovery of hard items. by relying on assimilated food, stable isotope and bayesian mixing models (simms) resolve many biases of traditional methods. simms can incorporate prior information (i.e. proportional diet composition) that may improve the precision in the estimated dietary composition. however few studies have a ... | 2013 | 24224031 |
| ovarian follicular morphometry of south american fur seal pups (arctophoca australis). | the aim of this study was to analyze the morphometric characteristics of ovarian follicles and their distribution in the ovarian cortex in south american fur seal pups (arctophoca australis). samples were obtained from animals stranded in the uruguayan atlantic coast. ovaries were dissected, fixed, weighed, and processed by standard histological techniques. ovarian weight increased with pup age and body length. there was an increase in the diameter of the oocytes (22.24 ± 0.6 to 68.2 ± 5.3 µm), ... | 2013 | 23959768 |
| respiratory mites ( orthohalarachne diminuata) and β-hemolytic streptococci-associated bronchopneumonia outbreak in south american fur seal pups ( arctocephalus australis). | although mites of the orthohalarachne genus are common parasites of otariids, their role as agents of disease and in causing population-level mortality is unknown. in the austral summer of 2016, there was an increase in mortality among south american fur seal ( arctocephalus australis) pups at guafo island, northern chilean patagonia. pups found dead or terminally ill had moderate to marked, multifocal, mucopurulent bronchopneumonia associated with large numbers of respiratory mites ( orthohalar ... | 2018 | 29369727 |
| solving a long-standing nomenclatorial controversy: designation of a neotype for the southern sea lion otaria flavescens (shaw, 1800). | during almost two centuries, two available specific epithets have competed for the southern sea lions of the genus otaria péron, 1816 (fig. 1), which is classically regarded as monotypic (but see below). the species distributes more or less continuously along the atlantic coast from southern brazil south to cape horn and along the pacific from northern peru to the west south american pacific coast . while some researchers have argued that the correct name for this species is phoca flavescens sha ... | 2019 | 30790968 |
| back to the future? late holocene marine food web structure in a warm climatic phase as a predictor of trophodynamics in a warmer south-western atlantic ocean. | stable carbon and nitrogen isotope ratios in the skeletal elements of both ancient and modern marine species from the beagle channel were used to compare the structure of late holocene and modern food webs, and predict potential changes as a result of a sea surface temperature (sst) increase in the region. complementary, ancient and modern shells of limpets and mussels were isotopically analysed to explore changes in the isotopic baseline and compare marine food webs through time after an approp ... | 2019 | 30430698 |
| helminth and respiratory mite lesions in pinnipeds from punta san juan, peru. | the tissues and parasites collected from peruvian fur seals (arctocephalus australis) and south american sea lions (otaria byronia) found dead at punta san juan, peru were examined. the respiratory mite, orthohalarachne attenuata infected 3 out of 32 examined fur seals and 3 out of 8 examined sea lions, however caused moderate to severe lymphohistiocytic pharyngitis only in fur seals. hookworms, uncinaria sp, infected 6 of the 32 examined fur seals causing variable degrees of hemorrhagic and eos ... | 2018 | 30367764 |
| mouth gape determines the response of marine top predators to long-term fishery-induced changes in food web structure. | here, we analyse changes throughout time in the isotopic niche of the franciscana dolphin (pontoporia blainvillei), the south american fur seal (arctocephalus australis) and the south american sea lion (otaria flavescens) from the río de la plata estuary and adjacent atlantic ocean to test the hypothesis that fishing may modify the diet of small-gape predators by reducing the average size of prey. the overall evidence, from stable isotope and stomach contents analyses, reveals major changes in r ... | 2018 | 30361482 |
| from mammals back to birds: host-switch of the acanthocephalan corynosoma australe from pinnipeds to the magellanic penguin spheniscus magellanicus. | trophically-transmitted parasites are regularly exposed to potential new hosts through food web interactions. successful colonization, or switching, to novel hosts, occur readily when 'donor' and 'target' hosts are phylogenetically related, whereas switching between distantly related hosts is rare and may result from stochastic factors (i.e. rare favourable mutations). this study investigates a host-switching event between a marine acanthocephalan specific to pinnipeds that is apparently able to ... | 2017 | 28981550 |
| toxoplasmosis and sarcocystis spp. infection in wild pinnipeds of the brazilian coast. | the protozoans toxoplasma gondii and sarcocystis spp. (sarcocystidae: apicomplexa) affect a wide variety of vertebrates. both have been reported to infect pinnipeds, with impacts on health ranging from inapparent to fulminant disease and death. however, little is known regarding their infections and associated pathology in south american pinnipeds. we used histological techniques to survey for the presence of t. gondii and sarcocystis spp. in 51 stranded pinnipeds from brazil. immunohistochemica ... | 2019 | 31724556 |
| new host and geographical records for parafilaroides normani (nematoda: filaroididae) dailey, 2009 in south american fur seal, arctocephalus australis, from southern brazil. | lungworms are a common finding in seals and fur seals around the world. however, from existing records, the biogeographical distribution of filaroid helminths appears to be restricted, and these parasites are endemic in only certain areas and species, mainly in the northern hemisphere. the occurrence of infection in pinniped species in the southern hemisphere is scarce. the objective of this work is to verify the prevalence of lungworms in arctocephalus australis in waters off the southern coast ... | 2020 | 33059788 |
| the skin structures and their role in the thermoregulation of the south american fur seal (arctocephalus australis). | the skin of the south american fur seal (arctocephalus australis) is important for animal thermoregulation in both terrestrial and aquatic environments. skin tissue samples were collected from a. australis for microscopic analysis and were related to anatomical references. the aim of this study was to describe the skin morphology, as well as to suggest the major anatomical regions and skin components involved in the thermoregulation of this species. using light microscopy, the skin of six animal ... | 2020 | 31908126 |
| the contrasting hidden consequences of parasitism: effects of a hematophagous nematode (uncinaria sp.) in the development of a marine mammal swimming behavior. | parasites are an important part of ecosystems, playing a critical role in their equilibrium. however, the consequences of parasitism beyond the direct effects associated with disease and mortality are not completely understood. this gap in knowledge is in part due to the difficulties to isolate the effect of single parasite species on physiological and behavioral traits in natural systems.the south american fur seal (arctocephalus australis)-hookworm (uncinaria sp.) interaction offers an ideal s ... | 2019 | 31015959 |
| parasitism elicits a stress response that allocates resources for immune function in south american fur seals (arctocephalus australis). | parasites can cause chronic stress in some animal species, and this type of stress response has been associated with adverse consequences for the host. in order to know whether parasitism elicited a stress response associated with decreased host fitness, hookworm (uncinaria sp.) infection was studied in a colony of south american fur seals (arctocephalus australis) in which hookworms infect nearly all pups born in a reproductive season. a parasite-free group was generated by treating a subset of ... | 2019 | 30986114 |
| first detection of plastic microfibers in a wild population of south american fur seals (arctocephalus australis) in the chilean northern patagonia. | the dramatic increase of microplastics (plastic fragments <5 mm) in marine environments is a problem that has attracted public attention globally. within the different types of microplastics, microfibres are the least studied (size <1 mm). we examined 51 female scats from a population in northern patagonia. our results showed no presence of microplastic particles, however 67% of them showed a remarkable abundance of microfibers, which until now had only been reported in animals fed in captivity. ... | 2018 | 30509835 |
| morphometrical and molecular evidence suggests cryptic diversity among hookworms (nematoda: uncinaria) that parasitize pinnipeds from the south-eastern pacific coasts. | hookworms of the genus uncinaria parasitize pinniped pups in various locations worldwide. four species have been described, two of which parasitize pinniped pups in the southern hemisphere: uncinaria hamiltoni parasitizes otaria flavescens and arctocephalus australis from the south american coast, and uncinaria sanguinis parasitizes neophoca cinerea from the australian coast. however, their geographical ranges and host specificity are unknown. uncinaria spp. are morphologically similar, but mole ... | 2018 | 30428941 |
| immune-mediated hookworm clearance and survival of a marine mammal decrease with warmer ocean temperatures. | increases in ocean temperature are associated with changes in the distribution of fish stocks, and the foraging regimes and maternal attendance patterns of marine mammals. however, it is not well understood how these changes affect offspring health and survival. the maternal attendance patterns and immunity of south american fur seals were assessed in a rookery where hookworm disease is the main cause of pup mortality. pups receiving higher levels of maternal attendance had a positive energy bal ... | 2018 | 30398149 |
| the life history strategy of a fur seal hookworm in relation to pathogenicity and host health status. | the strategies that parasites use to exploit their hosts can lead to adverse effects on human and animal populations. here, we describe the life cycle, epidemiology, and consequences of hookworm (uncinaria sp.) disease in south american fur seals (arctocephalus australis), and propose that hookworm adaptation to fur seal life history traits has led to maximizing transmission at high levels of parasite-induced anemia and mortality. fur seal pups acquire hookworms during their first days of life t ... | 2018 | 30069428 |
| identification of novel gammaherpesviruses in a south american fur seal ( arctocephalus australis) with ulcerative skin lesions. | there are few studies on pathogens affecting free-ranging pinnipeds from south america. we employed molecular techniques to identify a gammaherpesvirus infection by two putative novel herpesvirus species: otariid herpesvirus 5 (othv-5), possibly associated with ulcerative cutaneous lesions, and otariid herpesvirus 6 (othv-6) in a wild south american fur seal ( arctocephalus australis) that stranded alive in santa catarina state, southern brazil. here we provide new information regarding pinniped ... | 2018 | 29595382 |