RESUMO

Lymphomas are malignant neoplasms of the hematopoietic system arising from lymphocytes with highly variable biologic behavior. B-cell small lymphocytic lymphoma (B-SLL) is a non-Hodgkin lymphoma infrequently described in domestic and wild animals. The present study describes a case of B-SLL in a free-ranging adult male Arctocephalus australis in Brazil. The main necropsy findings included poor body condition, generalized lymphadenomegaly, severe and diffuse splenomegaly, and multiple, white to yellow nodules in the kidneys and small intestine. Histologically, these organs were partially or totally effaced by neoplastic small lymphocytes arranged in sheets, with moderate anisocytosis and anisokaryosis and a low mitotic count. These cells diffusely immunolabeled for CD79α and CD20, and were negative for CD3. A diagnosis of multicentric B-SLL was established and to the authors' knowledge, it has not been previously described in this genus.

Assuntos

RESUMO

Animal self-medication is thought to provide an adaptive advantage, as species would actively respond to a disease state or homeostatic imbalances. In wild nonhuman primates, it is challenging to differentiate plant use as part of the diet or as medication, especially because self-medication can be preventive or therapeutic. Here, we aimed to compile the available potential evidence on primate self-medication modes, investigating which proposed requirements are fulfilled for each plant species reported to date. We systematically reviewed the scientific literature on plant use for potential self-medication in wild nonhuman primates. To construct the extensive database, we extracted data on the primate species, study area, plant/plant's part used, the requirement(s) met for demonstrating self-medication modes, and self-medicative behavioral patterns. We also updated available information on plant's biological compounds and/or physical characteristics, pharmacological properties, and ethnomedical uses. We identified 575 plant species (135 families), used by 25 primate species (9 families). Plants were used by Old World monkeys (46.5%, n = 268 plant species), followed by apes (41%, n = 235), New World monkeys (13.4%, n = 77), and prosimians (1%, n = 6). We found three general types of self-medicative behaviors: ingestion (including, but not limited to, leaf-swallowing, seed-swallowing, and bitter pith chewing), topical (fur-rubbing), and nest fumigation. Plant uses were associated with antiparasitic, antibacterial, antimalarial, anti-inflammatory, insect repellent, among other properties. Self-medication is widespread in nonhuman primate species across Central and South America, Africa, Madagascar, and Asia. Long-term field research efforts and studies integrating different research sites and topics are urgent to advance our knowledge into the evolution of plant selection, medical traditions, and to bring insights into potentially novel medicinal plants and bioactive compounds to treat emergent or established primate and human diseases.

Assuntos

RESUMO

Pasteurellaceae family members obtain iron directly from host proteins or through siderophore-dependent mechanisms. Although Gallibacterum anatis expresses different virulence factors, its response to growth under iron restriction is unknown. G. anatis cultured in the presence of 2,2'-dipyridyl, up-expressed an approximately 65 kDa protein and repressed the expression of a 70 kDa protein. MALDI-TOF analysis of those proteins indicated homology with CirA (65 kDa), a protein involved in iron-siderophore acquisition in Mannheimia succinoproducens and a TonB-dependent receptor (70 kDa protein), a protein that binds chicken hemoglobin; however, G. anatis siderophore production was not detected by chromo azurol S (CAS)-BHI agar determination. This putative G. anatis siderophore receptor is under Fur control, but not the hemoglobin binding protein, as observed in G. anatis 12656-12 fur mutant (Ω fur 126.13) grown in the presence or not of 2,2'-dipyridyl. The addition of FeCl3 to the culture medium diminished the growth and biofilm production in approximately 30% and 35%, respectively, in the wild-type strain, but the growth of Ω fur 126.13 strain was not affected and biofilm production increased in 35%. G. anatis Ω fur 126.13 presented lower virulence when it was inoculated to 35-day-old chickens in comparison to the wild-type strain. The induction of more than one iron uptake mechanism could benefit pathogenic microorganisms such as Gallibacterium.

RESUMO

Gluconacetobacter diazotrophicus has been the focus of several studies aiming to understand the mechanisms behind this endophytic diazotrophic bacterium. The present study is the first global analysis of the early transcriptional response of exponentially growing G. diazotrophicus to iron, an essential cofactor for many enzymes involved in various metabolic pathways. RNA-seq, targeted gene mutagenesis and computational motif discovery tools were used to define the G. diazotrophicusfur regulon. The data analysis showed that genes encoding functions related to iron homeostasis were significantly upregulated in response to iron limitations. Certain genes involved in secondary metabolism were overexpressed under iron-limited conditions. In contrast, it was observed that the expression of genes involved in Fe-S cluster biosynthesis, flagellar biosynthesis and type IV secretion systems were downregulated in an iron-depleted culture medium. Our results support a model that controls transcription in G. diazotrophicus by fur function. The G. diazotrophicusfur protein was able to complement an E. colifur mutant. These results provide new insights into the effects of iron on the metabolism of G. diazotrophicus, as well as demonstrate the essentiality of this micronutrient for the main characteristics of plant growth promotion by G. diazotrophicus.

Assuntos

RESUMO

Pinnipeds found across islands provide an ideal opportunity to examine the evolutionary process of population subdivision affected by several mechanisms. Here, we report the genetic consequences of the geographic distribution of rookeries in Galapagos fur seals (GFS: Arctocephalus galapagoensis) in creating population structure. We show that rookeries across four islands (nine rookeries) are genetically structured into the following major groups: 1) a western cluster of individuals from Fernandina; 2) a central group from north and east Isabela, Santiago, and Pinta; and possibly, 3) a third cluster in the northeast from Pinta. Furthermore, asymmetric levels of gene flow obtained from eight microsatellites found migration from west Isabela to Fernandina islands (number of migrants Nm = 1), with imperceptible Nm in any other direction. Our findings suggest that the marked structuring of populations recovered in GFS is likely related to an interplay between long-term site fidelity and long-distance migration in both male and female individuals, probably influenced by varying degrees of marine productivity.

RESUMO

Marine debris, in particular plastic debris and debris related to fishing activities, have an impact on marine mammals and seabirds. In marine-coastal species such as otariids, we can detect the incidence of these interactions through land-based observations. In this study, we recorded and described interactions between marine debris and the otariids Arctocephalus australis and Otaria byronia in a natural protected area in Peru, according to age class categories. Between 2016 and 2020, we recorded 151 animals that were directly impacted and/or were observed interacting with marine debris. Residual collars from fishing gear, ropes, plastic bags and unidentified material were recorded. Direct interactions with debris at colonies (e.g., plastic bags) were also recorded, as well as animals evidenced interacting with hooks. The age class category and species with the highest number of individuals impacted by residual collars were adult female A. australis and subadult male O. byronia. Single-use plastics were the most commonly bitten/moved waste by animals in the reserve. In the case of hooks, these were mostly lodged in the mouths of otariids. Our results highlight the importance of continuing to promote segregation at source, as well as the correct disposal of waste, locally and globally, to mitigate impacts on marine fauna.

Assuntos

RESUMO

Adenoviruses are medium size nonenveloped viruses with a trend of coevolution with their hosts. We surveyed South American fur seals (Arctocephalus australis) and Humboldt penguins (Spheniscus humboldti) for adenoviruses at two sites from 2009 to 2012. Despite the common pattern of host specificity, some of the adenoviruses in our study were present in samples from unexpected host species. We identified mastadenoviruses, aviadenoviruses, and siadenoviruses in A. australis from Peru and Chile and in S. humboldti from Peru. The El Niño Southern Oscillation (ENSO) significantly reduces the productivity of the Humboldt upwelling system, which can change trophic and other ecological interactions, facilitating exposure to new pathogens. One aviadenovirus was detected in both the penguins and the fur seals, an interclass distance. This finding occurred only during the 2009 ENSO and not in 2010 or 2012. Further studies of viral diversity in sites with high-density mixed species populations are necessary to better understand viral evolution and the effect of environmental change on viral evolution and host specificity.

Assuntos

RESUMO

Sympatric species evolve mechanisms to avoid competition and coexist. In the Humboldt Current System (HCS), populations of South American sea lions (SASL, Otaria byronia) and South American fur seals (SAFS, Arctocephalus australis) fluctuate mostly due to ENSO events and prey availability. We evaluate population trajectories of Peruvian sympatric otariids and discuss mechanisms for competition and/or resource limitation. For this purpose, we analyzed population trajectories of SASL and SAFS in a sympatric breeding site in Punta San Juan, Peru between 2001 and 2019. Wavelet analysis was used to extract trends and derivatives to estimate rates and turning points. Age-class proportions and biomass times series were constructed from weekly counts and evaluated. Both populations show a growth phase and subsequent decline. SAFS started to decline ~2.25 years before and at a rate 1.5 times faster than SASL. Decrease in juvenile age-class suggests that resource limitation is the main contributing factor for current population decline.

Assuntos

RESUMO

OBJECTIVES: Here, we present the first record of stable colonies of the South American fur seal (Arctocephalus australis), in an area where their presence has never been documented (hereafter distribution gap), as well as an update of the current distribution range of the species in central Chile. RESULTS: A national synoptic aerial census of pinnipeds was performed during the austral summer of 2019 on the Chilean coast. An additional aerial census was conducted in the same area during the austral spring of 2019 as well as a maritime census during the austral summer of 2020. The data showed the presence of South American fur seals in central Chile within their well-known distribution gap. The total abundance was registered in three colonies where fur seals were sighted: one non-breeding colony, Punta Topocalma (summer 2019: mean = 46 ± 3; spring 2019: mean = 9 ± 1); and two breeding colonies, Punta Curaumilla (summer 2019: mean = 595 ± 7; spring 2019: mean = 45 ± 4; summer 2020: mean = 744 ± 5) and Isla Santa María (summer 2019: mean = 246 ± 6). Specifically, we suggest that it is crucial to elucidate the origin of the described settled colonies, and to determine whether there has been an augment in the distribution range from either the northern population, the southern population, or both simultaneously.

Assuntos

RESUMO

South American fur seals (Arctocephalus australis) are believed to reach the coast of Rio Grande do Sul (RS) through sea currents. They live in colonies and are frequently found resting on the beach. However, it is also common to find dead pinnipeds on beaches, sharing the environment with humans, domestic animals and other wild species on the coast and facilitating the transmission of pathogens. In the present study, a metagenomic approach was applied to evaluate the viral diversity in organs of fur seals found deceased along the coast of the state of RS, southern Brazil. The lungs and spleens of 29 animals were collected, macerated individually, pooled separately (one pool for lungs and another for spleens) and sequenced using the Illumina MiSeq platform. Sequences more closely related to members of the Anelloviridae and Circoviridae families were detected. Nine putative new species of anellovirus and one putative new genus, named Nitorquevirus, were described. Additionally, the circovirus sequences found in the lungs of A. australis have a common ancestor with PCV3, a proposed swine pathogen. Our study expanded the knowledge about viral communities in pinnipeds and could be useful for monitoring new viruses and potential viral sharing among wildlife, domestic animals, and humans.

Assuntos

RESUMO

Resumen Presentamos el registro de un individuo de oso hormiguero norteño (Tamandua mexicana) con color de pelaje anormalmente blanco. Este individuo fue fotografiado con una cámara trampa en el bosque seco ecuatorial en el departamento de Lambayeque, a 560 m de altitud, en del noroeste del Perú. No pudimos diferenciar si la causa de esta aberración cromática correspondió a un caso de albinismo o de leucismo, sin embargo, destacamos este primer registro excepcional para la especie en Perú. Adicionalmente, hacemos una revisión de su presencia en el extremo sur de su distribución global.

Abstract We present the record of an individual of northern tamandua (Tamandua mexicana) with abnormal white coloration that was photographed with a camera trap in the equatorial dry forest in the department of Lambayeque, at elevation of 560 m, northwest Peru. We could not determine if this chromatic aberration was a case of leucism or albinism, but we highlight this uncommon record as the first for Peru. We also revised the information about its presence in the southern portion of its global range.

RESUMO

Aquaculture is a fast growing industry with its development hampered by bacterial diseases. Vibriosis caused by Harveyi clade strains is known for causing heavy loss especially in shrimp aquaculture farms. For farm treatment and pathogen spread management, veterinarians and researchers need reliable bacterial identification tools. A range of identification methods have been presented for Vibrio spp. in recent literature but little feedback on their performance have been made available to this day. This study aims at comparing Vibrio spp. identification methods and providing guidance on their use. Fifty farms were sampled and bacterial colonies were isolated using specific culture media before microscopic analysis and genomic profiling using ERIC-PCR. A preliminary identification step was carried out using MALDI-ToF mass spectrometry. Four methods were compared for strain identification on 14 newly isolated Harveyi clade Vibrio spp. strains: whole genome sequencing (digital DNA DNA Hybridization (dDDH)), 5 MLSA schemes, ferric uptake regulation (fur) and lecithin-dependent haemolysin (ldh) single gene based identification methods. Apart from dDDH which is a reference method, no technique could identify all the isolates to the species level. The other tested techniques allowed a faster, cheaper but sub genus clade identification which can be interesting when absolute precision is not required. In this regard, MALDI-ToF and fur based identification seemed especially promising.

Assuntos

RESUMO

A clinical case in which skin and hair color change occurred after sacrococcygeal epidural anesthesia in a nine-month-old Siamese cross queen undergoing ovariohysterectomy (OHE) is described. Six weeks after surgery, during a re-check, it was noted that in the sacrococcygeal region the color of the skin and new hair growth was dark with a color comparable to the color present on the body extremities (muzzle, pinnae, legs, and tail). The skin and new hair growth of the shaved abdomen presented a standard color. The key enzyme of the melanogenic pathway in mammals is tyrosinase (TYR), and the Siamese temperature-sensitive phenotype is the result of genetic mutations that makes TYR function thermolabile. The activity of TYR in these cats is limited to the extremities where the temperature is lower while pigment production is impaired in the other body areas. The trichotomy of the sacrococcygeal region performed during wintertime in an outdoor cat was probably the trigger for increased activity of TYR in this area promoting pigment production. The absence of the same alterations in the abdominal area may be justified by less exposure of that region to the external environment, as well as to the feline habits of sedentarism, that avoid significant cooling in these regions. This report highlights the importance of taking this type of occurrence into account when performing an epidural in the Siamese cat breed. Also, to avoid skin color change in this breed, the authors recommend a midline abdominal instead of a flank approach to perform OHE.(AU)

Descreve-se um caso clínico no qual ocorreu mudança na cor da pele e do pelo após anestesia epidural sacrococcígea numa gata cruzada de raça Siamês de nove meses submetida à ovariohisterectomia (OVH). Seis semanas após a cirurgia, durante uma avaliação pós-operatória, notou-se que na região sacrococcígea, a cor da pele e o crescimento do pelo apresentavam uma cor escura, comparável à das extremidades do corpo (face, orelhas, membros e cauda). A pele e o crescimento do pelo do abdómen, que também havia sido tosquiado, apresentavam uma cor padrão. A enzima chave da via melanogênica em mamíferos é a tirosinase (TYR) e o fenótipo siamês sensível à temperatura é o resultado de mutações genéticas que tornam a função TYR termolábil. A atividade da TYR nestes gatos é limitada às extremidades onde a temperatura é mais baixa, enquanto a produção de pigmento é prejudicada em outras áreas do corpo. A tricotomia da região sacrococcígea realizada durante o inverno nesta gata com acesso livre ao ambiente externo, provavelmente determinou um aumento da atividade da TYR nesta área, promovendo a produção de pigmento. A ausência das mesmas alterações na região abdominal pode ser justificada pela menor exposição desta área do corpo ao ambiente externo, também devido aos hábitos felinos de sedentarismo, que evitam resfriamento significativo nestas regiões. Este relato destaca a importância de se levar em consideração a possibilidade deste tipo de ocorrência quando da realização de uma anestesia epidural nesta raça de gatos. Além disso, os autores recomendam uma abordagem abdominal na linha média ao invés de uma abordagem de flanco para realizar a OVH nesta raça, a fim de evitar a alteração da cor da pele.(AU)

Assuntos

RESUMO

A clinical case in which skin and hair color change occurred after sacrococcygeal epidural anesthesia in a nine-month-old Siamese cross queen undergoing ovariohysterectomy (OHE) is described. Six weeks after surgery, during a re-check, it was noted that in the sacrococcygeal region the color of the skin and new hair growth was dark with a color comparable to the color present on the body extremities (muzzle, pinnae, legs, and tail). The skin and new hair growth of the shaved abdomen presented a standard color. The key enzyme of the melanogenic pathway in mammals is tyrosinase (TYR), and the Siamese temperature-sensitive phenotype is the result of genetic mutations that makes TYR function thermolabile. The activity of TYR in these cats is limited to the extremities where the temperature is lower while pigment production is impaired in the other body areas. The trichotomy of the sacrococcygeal region performed during wintertime in an outdoor cat was probably the trigger for increased activity of TYR in this area promoting pigment production. The absence of the same alterations in the abdominal area may be justified by less exposure of that region to the external environment, as well as to the feline habits of sedentarism, that avoid significant cooling in these regions. This report highlights the importance of taking this type of occurrence into account when performing an epidural in the Siamese cat breed. Also, to avoid skin color change in this breed, the authors recommend a midline abdominal instead of a flank approach to perform OHE.(AU)

Descreve-se um caso clínico no qual ocorreu mudança na cor da pele e do pelo após anestesia epidural sacrococcígea numa gata cruzada de raça Siamês de nove meses submetida à ovariohisterectomia (OVH). Seis semanas após a cirurgia, durante uma avaliação pós-operatória, notou-se que na região sacrococcígea, a cor da pele e o crescimento do pelo apresentavam uma cor escura, comparável à das extremidades do corpo (face, orelhas, membros e cauda). A pele e o crescimento do pelo do abdómen, que também havia sido tosquiado, apresentavam uma cor padrão. A enzima chave da via melanogênica em mamíferos é a tirosinase (TYR) e o fenótipo siamês sensível à temperatura é o resultado de mutações genéticas que tornam a função TYR termolábil. A atividade da TYR nestes gatos é limitada às extremidades onde a temperatura é mais baixa, enquanto a produção de pigmento é prejudicada em outras áreas do corpo. A tricotomia da região sacrococcígea realizada durante o inverno nesta gata com acesso livre ao ambiente externo, provavelmente determinou um aumento da atividade da TYR nesta área, promovendo a produção de pigmento. A ausência das mesmas alterações na região abdominal pode ser justificada pela menor exposição desta área do corpo ao ambiente externo, também devido aos hábitos felinos de sedentarismo, que evitam resfriamento significativo nestas regiões. Este relato destaca a importância de se levar em consideração a possibilidade deste tipo de ocorrência quando da realização de uma anestesia epidural nesta raça de gatos. Além disso, os autores recomendam uma abordagem abdominal na linha média ao invés de uma abordagem de flanco para realizar a OVH nesta raça, a fim de evitar a alteração da cor da pele.(AU)

Assuntos

RESUMO

We studied the diet of non-breeding male Antarctic fur Seals Arctocephalus gazella (Peters, 1875) at two different localities of the South Shetland Islands: Stranger Point, King George Island/Isla 25 de Mayo and Duthoit Point, Nelson Island, by the analysis of 65 faecal samples collected in February 2012. Overall, Antarctic krill Euphausia superba (Dana, 1850) and fish were the main prey taxa followed by penguins and cephalopods. Myctophids were dominant among fish; Gymnoscopelus nicholsi (Gilbert, 1911) was the most important prey species at both sampling sites, followed by Electrona antarctica (Gunther, 1878) at Stranger Point and by the nototheniid Pleuragramma antarctica (Boulenger, 1902) at Duthoit Point. The relative similarity found in the dietary composition of fur seals from both locations suggest they might have been sharing common feeding areas. Our results were compared with those reported in the literature for different localities of the South Shetland Islands and the Scotia Sea region. The absence of formerly harvested demersal notothenioid species in the diet of fur seals may reflect the negative impact that commercial fisheries had on some fish populations and supports the importance of implementing long-term monitoring studies on the feeding habits of A. gazella in the area.(AU)

Se estudió la dieta de ejemplares macho no reproductivos de lobo fino antártico, Arctocephalus gazella (Peters, 1875) en dos localidades de las Islas Shetland del Sur: Cabo Funes/Punta Stranger, Isla 25 de Mayo / Isla Rey Jorge y Punta Duthoit, Isla Nelson; por medio del análisis de 65 muestras de materia fecal colectadas en Febrero de 2012. En general, el krill antártico Euphausia superba (Dana, 1850) y los peces fueron los taxa presa más consumidos, seguidos por pingüinos y cefalópodos. Entre los peces, los mictófidos fueron dominantes; Gymnoscopelus nicholsi (Gilbert, 1911) fue la especie más importante en ambos apostaderos, seguido por Electrona antarctica (Gunther, 1878) en Punta Stranger y por el nototénido Pleuragramma antarctica (Boulenger, 1902) en Punta Duthoit. La similitud hallada en la composición dietaria de los agrupamientos de lobo estudiados sugiere áreas de alimentación en común. Nuestros resultados fueron comparados con aquellos reportados en la literatura para diferentes localidades de las Islas Shetland del Sur y la región del Mar de Scotia. La ausencia de especies de nototenoideos demersales históricamente diezmadas en la dieta del lobo fino podría estar reflejando el impacto negativo que las pesquerías comerciales han tenido sobre algunas poblaciones de peces y enfatizar la necesidad de realizar un monitoreo a largo plazo de los hábitos alimentarios de A. gazella en el archipiélago de las Islas Shetland del Sur.(AU)

Assuntos

RESUMO

We studied the diet of non-breeding male Antarctic fur Seals Arctocephalus gazella (Peters, 1875) at two different localities of the South Shetland Islands: Stranger Point, King George Island/Isla 25 de Mayo and Duthoit Point, Nelson Island, by the analysis of 65 faecal samples collected in February 2012. Overall, Antarctic krill Euphausia superba (Dana, 1850) and fish were the main prey taxa followed by penguins and cephalopods. Myctophids were dominant among fish; Gymnoscopelus nicholsi (Gilbert, 1911) was the most important prey species at both sampling sites, followed by Electrona antarctica (Gunther, 1878) at Stranger Point and by the nototheniid Pleuragramma antarctica (Boulenger, 1902) at Duthoit Point. The relative similarity found in the dietary composition of fur seals from both locations suggest they might have been sharing common feeding areas. Our results were compared with those reported in the literature for different localities of the South Shetland Islands and the Scotia Sea region. The absence of formerly harvested demersal notothenioid species in the diet of fur seals may reflect the negative impact that commercial fisheries had on some fish populations and supports the importance of implementing long-term monitoring studies on the feeding habits of A. gazella in the area.

Se estudió la dieta de ejemplares macho no reproductivos de lobo fino antártico, Arctocephalus gazella (Peters, 1875) en dos localidades de las Islas Shetland del Sur: Cabo Funes/Punta Stranger, Isla 25 de Mayo / Isla Rey Jorge y Punta Duthoit, Isla Nelson; por medio del análisis de 65 muestras de materia fecal colectadas en Febrero de 2012. En general, el krill antártico Euphausia superba (Dana, 1850) y los peces fueron los taxa presa más consumidos, seguidos por pingüinos y cefalópodos. Entre los peces, los mictófidos fueron dominantes; Gymnoscopelus nicholsi (Gilbert, 1911) fue la especie más importante en ambos apostaderos, seguido por Electrona antarctica (Gunther, 1878) en Punta Stranger y por el nototénido Pleuragramma antarctica (Boulenger, 1902) en Punta Duthoit. La similitud hallada en la composición dietaria de los agrupamientos de lobo estudiados sugiere áreas de alimentación en común. Nuestros resultados fueron comparados con aquellos reportados en la literatura para diferentes localidades de las Islas Shetland del Sur y la región del Mar de Scotia. La ausencia de especies de nototenoideos demersales históricamente diezmadas en la dieta del lobo fino podría estar reflejando el impacto negativo que las pesquerías comerciales han tenido sobre algunas poblaciones de peces y enfatizar la necesidad de realizar un monitoreo a largo plazo de los hábitos alimentarios de A. gazella en el archipiélago de las Islas Shetland del Sur.

Assuntos

RESUMO

RESUMEN Se estudió la dieta de ejemplares macho no reproductivos de lobo fino antártico, Arctocephalus gazella (Peters, 1875) en dos localidades de las Islas Shetland del Sur: Cabo Funes/Punta Stranger, Isla 25 de Mayo / Isla Rey Jorge y Punta Duthoit, Isla Nelson; por medio del análisis de 65 muestras de materia fecal colectadas en Febrero de 2012. En general, el krill antártico Euphausia superba (Dana, 1850) y los peces fueron los taxa presa más consumidos, seguidos por pingüinos y cefalópodos. Entre los peces, los mictófidos fueron dominantes; Gymnoscopelus nicholsi (Gilbert, 1911) fue la especie más importante en ambos apostaderos, seguido por Electrona antarctica (Gunther, 1878) en Punta Stranger y por el nototénido Pleuragramma antarctica (Boulenger, 1902) en Punta Duthoit. La similitud hallada en la composición dietaria de los agrupamientos de lobo estudiados sugiere áreas de alimentación en común. Nuestros resultados fueron comparados con aquellos reportados en la literatura para diferentes localidades de las Islas Shetland del Sur y la región del Mar de Scotia. La ausencia de especies de nototenoideos demersales históricamente diezmadas en la dieta del lobo fino podría estar reflejando el impacto negativo que las pesquerías comerciales han tenido sobre algunas poblaciones de peces y enfatizar la necesidad de realizar un monitoreo a largo plazo de los hábitos alimentarios de A. gazella en el archipiélago de las Islas Shetland del Sur.

ABSTRACT We studied the diet of non-breeding male Antarctic fur Seals Arctocephalus gazella (Peters, 1875) at two different localities of the South Shetland Islands: Stranger Point, King George Island/Isla 25 de Mayo and Duthoit Point, Nelson Island, by the analysis of 65 faecal samples collected in February 2012. Overall, Antarctic krill Euphausia superba (Dana, 1850) and fish were the main prey taxa followed by penguins and cephalopods. Myctophids were dominant among fish; Gymnoscopelus nicholsi (Gilbert, 1911) was the most important prey species at both sampling sites, followed by Electrona antarctica (Gunther, 1878) at Stranger Point and by the nototheniid Pleuragramma antarctica (Boulenger, 1902) at Duthoit Point. The relative similarity found in the dietary composition of fur seals from both locations suggest they might have been sharing common feeding areas. Our results were compared with those reported in the literature for different localities of the South Shetland Islands and the Scotia Sea region. The absence of formerly harvested demersal notothenioid species in the diet of fur seals may reflect the negative impact that commercial fisheries had on some fish populations and supports the importance of implementing long-term monitoring studies on the feeding habits of A. gazella in the area.

RESUMO

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 of Brazil. Twenty subadult specimens of A. australis found recently dead on the southern coast of Brazil were necropsied and their lungs were examined. Parasitic cysts were found in only one specimen (prevalence of 5%). The helminths were morphologically identified as Parafilaroides normani (Metastrongyloidea: Filaroididae). This helminth species has been reported in pinnipeds from Australia, New Zealand and South Africa. This is the first record of P. normani in A. australis and for the western South Atlantic, providing additional data regarding the biogeographic distribution of the parasite.

Assuntos

RESUMO

This is the first study to investigate mercury (Hg) contamination in felid species in the Brazilian Amazon. We collected 26 fur samples from wild felids of four species (Puma concolor, Panthera onca, Leopardus pardalis and Leopardus wiedii) occurring in the Mamirauá and Amanã sustainable development reserves, in the state of Amazonas. Samples were from museum specimens, except for five P. onca samples collected from free-living individuals. Total Hg concentrations ranged from 0.12 to 48.1 µg g-1. Concentrations of Hg did not differ significantly between museum specimens and live individuals of P. onca, but varied significantly among species, with significantly higher concentrations for P. onca and L. pardalis, which could be related to factors such as diet and habitat. (AU)

Assuntos

RESUMO

Research using stable isotopes analysis (SIA) of carbon (δ13 C) and nitrogen (δ15 N) in blood components is lacking, because of the challenge of sample collection, processing, and storage in remote areas. There also is a paucity of information regarding the effect of tissue biochemical composition on isotopic ratios with few comparisons among taxa. We collected blood samples from shortfin mako sharks (n = 70; 2016) and Guadalupe fur seals (n = 25; 2017). All samples were centrifuged to obtain plasma from sharks and serum from the Guadalupe fur seals, and all the samples were prepared for SIA and analyzed using a Costech 4010 elemental analyzer interfaced with a Delta V Plus isotope ratio mass spectrometer. We found significant differences between plasma δ13 C values of shortfin mako sharks (-17.6 ± 0.9‰) and serum of Guadalupe fur seals (-20.3 ± 1.2‰), but we did not find any differences for δ15 N values between the two species. The differences in δ13 C values between species are probably due to the specific blood composition and to the different biochemical characteristics and different adaptations within taxa. These findings highlight the importance of further research on the influence of biochemistry features on isotopic results, in this way a more accurate assessment will be possible for this factor, separating it from the dietary influences on stable isotopic values.

Assuntos