Arctocephalus australis (Zimmermann, 1783) (lobo-marinho-sul-americano), é um carnívoro marinho com ampla distribuição, que ocorre nas costas leste e oeste da América do Sul, desde o Peru até o Brasil. O maior número de registros de espécimes de A. australis no Brasil ocorre no estado do Rio Grande do Sul, onde estão localizadas as duas principais áreas de concentração de pinípedes no País. Apesar de não haver colônias reprodutivas da espécie no litoral brasileiro, todos os anos, principalmente no período entre junho e outubro, inúmeros animais (vivos e mortos) são encontrados no litoral do País. O objetivo deste trabalho foi caracterizar as causas de morte mais comuns nos animais que ocorrem no litoral norte do estado do Rio Grande do Sul em 2012 e 2013. Para isso, foi realizada necropsia em 50 animais encontrados mortos na praia. Dos animais necropsiados, 30% tiveram a morte associada com trauma severo, apresentando laceração da musculatura, hemorragia extensa e politraumatismo e 8% trauma severo com laceração da musculatura e hemorragia extensa. Ainda 14% tiveram como causa mortis alterações no trato respiratório, 6% apresentaram alterações no trato gastrointestinal, 4% no sistema muscular, 4% no sistema nervoso central, 2% no sistema hepático e 2% com alterações no trato reprodutivo. Ainda, 18% tiveram a morte associada à caquexia e em 12% não foi possível concluir a causa da morte. Os principais achados são discutidos, bem como fatores antrópicos e não antrópicos que podem ter causado ou contribuído para o óbito dos animais.

Arctocephalus australis (Zimmermann, 1783) (lobo-marinho-sul-americano), é um carnívoro marinho com ampla distribuição, que ocorre nas costas leste e oeste da América do Sul, desde o Peru até o Brasil. O maior número de registros de espécimes de A. australis no Brasil ocorre no estado do Rio Grande do Sul, onde estão localizadas as duas principais áreas de concentração de pinípedes no País. Apesar de não haver colônias reprodutivas da espécie no litoral brasileiro, todos os anos, principalmente no período entre junho e outubro, inúmeros animais (vivos e mortos) são encontrados no litoral do País. O objetivo deste trabalho foi caracterizar as causas de morte mais comuns nos animais que ocorrem no litoral norte do estado do Rio Grande do Sul em 2012 e 2013. Para isso, foi realizada necropsia em 50 animais encontrados mortos na praia. Dos animais necropsiados, 30% tiveram a morte associada com trauma severo, apresentando laceração da musculatura, hemorragia extensa e politraumatismo e 8% trauma severo com laceração da musculatura e hemorragia extensa. Ainda 14% tiveram como causa mortis alterações no trato respiratório, 6% apresentaram alterações no trato gastrointestinal, 4% no sistema muscular, 4% no sistema nervoso central, 2% no sistema hepático e 2% com alterações no trato reprodutivo. Ainda, 18% tiveram a morte associada à caquexia e em 12% não foi possível concluir a causa da morte. Os principais achados são discutidos, bem como fatores antrópicos e não antrópicos que podem ter causado ou contribuído para o óbito dos animais.

O lobo-marinho-sul-americano (Arctocephalus australis) membro da Ordem Carnivora, é comumente visto nos períodos de outono e inverno na costa brasileira do Rio Grande do Sul até o Rio de Janeiro, porém, sem colônias reprodutivas estabelecidas. A espécie pertence ao grupo dos pinípedes, carnívoros com membros em forma de nadadeiras que vivem em ambiente aquático e terrestre. Estudos sobre a morfologia da pele em pinípedes são raros e antigos, destes procederam muitos relatos divergentes, em virtude da colheita da pele sem referências anatômicas. O objetivo desta pesquisa foi descrever o sistema tegumentar da espécie Arctocephalus australis, utilizando animais que vieram a óbito por causas naturais de uma colônia reprodutiva do Uruguai. As áreas corporais colhidas dorso-ventralmente foram identificadas anatomicamente. Essas regiões foram examinadas por microscopia óptica, segundo critérios histológicos, histomorfométricos, histoquímicos e imuno-histoquímicos nas diferentes estruturas que constituem o sistema tegumentar. A pele do Arctocephalus australis apresentou diferenças entre as regiões de epiderme delgada e espessa. A epiderme delgada apresentou maior quantidade de pêlos do que a epiderme espessa, a qual em algumas regiões era destituída destes. Como os demais mamíferos, a pele do lobo-marinho-sul-americano apresentou glândulas sebáceas, glândulas sudoríparas apócrinas e merócrinas. As nadadeiras apresentaram o maior número de especializações entre as regiões do corpo estudadas, especialmente vinculadas à termorregulação, como o maior volume de glândulas sudoríparas e secções vasculares. Esta pesquisa apontou os aspectos morfofuncionais relacionados à biologia da espécie em ambientes distintos, e esclareceu alguns dados controversos na literatura sobre o sistema tegumentar em pinípedes. / The South American fur seal (Arctocephalus australis) members of the Order Carnivora is usually seen during the autumn and winter season in the Brazilian coast from Rio Grande do Sul to Rio de Janeiro, however, there are no reports of reproductive colonies established. The species belongs to the group of pinnipeds, carnivorous with limbs fin-shaped that inhabits both terrestrial and aquatic environments. Studies of the skin morphology are rare and ancient; these studies have arisen many divergent reports, due to sampling of the skin without anatomical references. The purpose of this research was to describe the integumentary system of the species Arctocephalus australis, using animals that came to death by natural cases from reproductive colonies from Uruguay. The body dorsal and ventral regions were identified anatomically. These regions were examined by light microscopy, according to the histological, histomophometric, histochemical and immunohistochemical criteria in the different structures constituting the integumentary system. The skin of the Arctocephalus australis showed differences between the thin and thick epidermis. The thin epidermis showed larger amount of hair follicles than the thicker epidermis, which in some regions was devoid of hair. As well as the other mammals, the South-american-fur-seal skin showed sebaceous glands, apocrine and eccrine sweat glands. The limbs showed the largest number of the specialization among the regions of the body examined, particularly related to thermoregulation, as well as the largest volume fraction of sweat glands and vascular sections. This research pointed the morphofunctional aspects related to biology of the species in different environments, and elucidated some controversial data in the investigation about the integumentary system in pinnipeds.

O lobo-marinho-sul-americano (Arctocephalus australis) membro da Ordem Carnivora, é comumente visto nos períodos de outono e inverno na costa brasileira do Rio Grande do Sul até o Rio de Janeiro, porém, sem colônias reprodutivas estabelecidas. A espécie pertence ao grupo dos pinípedes, carnívoros com membros em forma de nadadeiras que vivem em ambiente aquático e terrestre. Estudos sobre a morfologia da pele em pinípedes são raros e antigos, destes procederam muitos relatos divergentes, em virtude da colheita da pele sem referências anatômicas. O objetivo desta pesquisa foi descrever o sistema tegumentar da espécie Arctocephalus australis, utilizando animais que vieram a óbito por causas naturais de uma colônia reprodutiva do Uruguai. As áreas corporais colhidas dorso-ventralmente foram identificadas anatomicamente. Essas regiões foram examinadas por microscopia óptica, segundo critérios histológicos, histomorfométricos, histoquímicos e imuno-histoquímicos nas diferentes estruturas que constituem o sistema tegumentar. A pele do Arctocephalus australis apresentou diferenças entre as regiões de epiderme delgada e espessa. A epiderme delgada apresentou maior quantidade de pêlos do que a epiderme espessa, a qual em algumas regiões era destituída destes. Como os demais mamíferos, a pele do lobo-marinho-sul-americano apresentou glândulas sebáceas, glândulas sudoríparas apócrinas e merócrinas. As nadadeiras apresentaram o maior número de especializações entre as regiões do corpo estudadas, especialmente vinculadas à termorregulação, como o maior volume de glândulas sudoríparas e secções vasculares. Esta pesquisa apontou os aspectos morfofuncionais relacionados à biologia da espécie em ambientes distintos, e esclareceu alguns dados controversos na literatura sobre o sistema tegumentar em pinípedes. / The South American fur seal (Arctocephalus australis) members of the Order Carnivora is usually seen during the autumn and winter season in the Brazilian coast from Rio Grande do Sul to Rio de Janeiro, however, there are no reports of reproductive colonies established. The species belongs to the group of pinnipeds, carnivorous with limbs fin-shaped that inhabits both terrestrial and aquatic environments. Studies of the skin morphology are rare and ancient; these studies have arisen many divergent reports, due to sampling of the skin without anatomical references. The purpose of this research was to describe the integumentary system of the species Arctocephalus australis, using animals that came to death by natural cases from reproductive colonies from Uruguay. The body dorsal and ventral regions were identified anatomically. These regions were examined by light microscopy, according to the histological, histomophometric, histochemical and immunohistochemical criteria in the different structures constituting the integumentary system. The skin of the Arctocephalus australis showed differences between the thin and thick epidermis. The thin epidermis showed larger amount of hair follicles than the thicker epidermis, which in some regions was devoid of hair. As well as the other mammals, the South-american-fur-seal skin showed sebaceous glands, apocrine and eccrine sweat glands. The limbs showed the largest number of the specialization among the regions of the body examined, particularly related to thermoregulation, as well as the largest volume fraction of sweat glands and vascular sections. This research pointed the morphofunctional aspects related to biology of the species in different environments, and elucidated some controversial data in the investigation about the integumentary system in pinnipeds.

Colony dynamics, maternal investment, and indicators of health were investigated for the New Zealand fur seal (Arctocephalus forsteri) over four austral summers, 2001- 2005. Effort was focused at the Ohau Point seal colony, north of Kaikoura. Two colonies at Banks Peninsula were included for comparisons of colony growth and pup condition. A range of other colonies were also included for making comparisons about colony dynamics and health indices. Colony dynamics were investigated through mark-recapture estimates of pup production and daily census of all individuals at the Ohau Point colony. Maternal attendance patterns were observed through behavioural observations of known females (n = 120), the use of VHF radio transmitters (n = 33), and female mass and body condition estimates (n = 51). Maternal investment was also investigated through longitudinal sampling of pup mass and growth rates. Parameters used to indicate colony health were: body condition, growth, presence of parasites, and the levels and common causes of mortality. The influence of parasites on pup growth was tested using treatment of selected pups with Ivermectin anti-helmentic medication, and mortality in the region was investigated through reports of dead individuals, and post mortems of those found fresh. The Ohau Point colony is in an exponential state of growth, and pup mass and condition was higher and responded to changes in environmental variables differently than at the Banks Peninsula colonies. Lactation lengths were consistently longer at Ohau Point than is typically reported for the species (323-355 days vs. 285 days). Maternal investment strategies were indicative of a close, reliable food source, and showed flexibility between years through extension of foraging trip durations and the increased use of overnight foraging trips. Individual strategies did not significantly influence pup growth. However, increased maternal condition and the ability to respond to inter-annual changes in resource availability resulted in accelerated pup growth even during an El Niño event. The incidence of pups with intestinal parasites was low at Ohau Point, and the average mass of treated and non-treated pups did not differ. Pup mortality in the region was low (3% to 50 days old), however, mortality of older pups was greatly influenced by the proximity of humans, with 2/3 of pup mortality observed between the age of 50 days and weaning being caused by car collisions. The results suggest that population dynamics and maternal investment in the region are greatly influenced by local variables, notably the presence of an accessible food source within close proximity to the colony. Various indicators of health reflect a growing colony in good condition, and the presence of a reliable food source may influence the maximum density and carrying capacity the colony is able to sustain. However, some concerns are raised about the influence of human interactions in the region, and how this may affect mortality and colony dynamics in the future. Extra fencing along the Ohau Point colony is recommended to provide added protection from the road. Continued monitoring of mortality and health indices in the region is also recommended for comparison with other colonies as Ohau Point reaches carrying capacity and density-dependent pressures increase.

<p>Odor discrimination ability was tested in four female South African fur seals (<em>Arctocephalus pusillus pusillus</em>) using a food-rewarded two-choice instrumental conditioning paradigm. The seals’ ability to distinguish between members of homologous series of aliphatic ketones (2-butanone to 2-heptanone) and alcohols (1-butanol to 1-heptanol) was assessed. The results showed that three out of four seals successfully discriminated between all of their stimulus combinations in both classes of odorants. One seal succeeded to reach the discrimination criterion with all 2-ketones but failed with all 1-alcohols.</p><p>No significant correlation between odor discrimination performance and structural similarity of the odorants in terms of differences in carbon chain length was found in either of the two chemical classes. Furthermore, it was found that the 2-ketones were significantly better discriminated than the 1-alcohols. The fact that both classes of odorants are known to be present in the natural environment of seals provides a possible explanation as to why most of the seals were able to successfully discriminate between them. The results of the present study support the notion that the sense of smell may play an important role in behavioral contexts such as social communication, foraging and reproductive behavior of fur seals.</p>

Odor discrimination ability was tested in four female South African fur seals (Arctocephalus pusillus pusillus) using a food-rewarded two-choice instrumental conditioning paradigm. The seals’ ability to distinguish between members of homologous series of aliphatic ketones (2-butanone to 2-heptanone) and alcohols (1-butanol to 1-heptanol) was assessed. The results showed that three out of four seals successfully discriminated between all of their stimulus combinations in both classes of odorants. One seal succeeded to reach the discrimination criterion with all 2-ketones but failed with all 1-alcohols. No significant correlation between odor discrimination performance and structural similarity of the odorants in terms of differences in carbon chain length was found in either of the two chemical classes. Furthermore, it was found that the 2-ketones were significantly better discriminated than the 1-alcohols. The fact that both classes of odorants are known to be present in the natural environment of seals provides a possible explanation as to why most of the seals were able to successfully discriminate between them. The results of the present study support the notion that the sense of smell may play an important role in behavioral contexts such as social communication, foraging and reproductive behavior of fur seals.

The sense of smell in marine mammals is traditionally thought to be poor. However, increasing evidence suggests that pinnipeds may use their sense of smell in a variety of behavioral contexts including communication, foraging, food selection, and reproduction. Using a food-rewarded two-choice instrumental conditioning paradigm, I assessed the ability of South African fur seals, Arctocephalus pusillus, to discriminate between 12 enantiomeric odor pairs, that is, between odorants that are identical in structure except for chirality. The fur seals significantly discriminated between eight out of the twelve odor pairs (according to p &lt; 0.05, with carvone, dihydrocarvone, dihydrocarveol, limonene oxide, menthol, beta-citronellol, fenchone, and alpha-pinene), and failed with only four odor pairs (isopulegol, rose oxide, limonene, and camphor). No significant differences in performance were found between the animals (p &gt; 0.05). Cross-species comparisons between the olfactory performance of the fur seals and that of other species previously tested on the same set of odor pairs lend further support to the notion that the relative size of the olfactory bulbs is not a reliable predictor of olfactory discrimination abilities. The results of the present study suggest that sense of smell may play an important and hitherto underestimated role in regulating the behavior of fur seals.

Colony dynamics, maternal investment, and indicators of health were investigated for the New Zealand fur seal (Arctocephalus forsteri) over four austral summers, 2001- 2005. Effort was focused at the Ohau Point seal colony, north of Kaikoura. Two colonies at Banks Peninsula were included for comparisons of colony growth and pup condition. A range of other colonies were also included for making comparisons about colony dynamics and health indices. Colony dynamics were investigated through mark-recapture estimates of pup production and daily census of all individuals at the Ohau Point colony. Maternal attendance patterns were observed through behavioural observations of known females (n = 120), the use of VHF radio transmitters (n = 33), and female mass and body condition estimates (n = 51). Maternal investment was also investigated through longitudinal sampling of pup mass and growth rates. Parameters used to indicate colony health were: body condition, growth, presence of parasites, and the levels and common causes of mortality. The influence of parasites on pup growth was tested using treatment of selected pups with Ivermectin anti-helmentic medication, and mortality in the region was investigated through reports of dead individuals, and post mortems of those found fresh. The Ohau Point colony is in an exponential state of growth, and pup mass and condition was higher and responded to changes in environmental variables differently than at the Banks Peninsula colonies. Lactation lengths were consistently longer at Ohau Point than is typically reported for the species (323-355 days vs. 285 days). Maternal investment strategies were indicative of a close, reliable food source, and showed flexibility between years through extension of foraging trip durations and the increased use of overnight foraging trips. Individual strategies did not significantly influence pup growth. However, increased maternal condition and the ability to respond to inter-annual changes in resource availability resulted in accelerated pup growth even during an El Niño event. The incidence of pups with intestinal parasites was low at Ohau Point, and the average mass of treated and non-treated pups did not differ. Pup mortality in the region was low (3% to 50 days old), however, mortality of older pups was greatly influenced by the proximity of humans, with 2/3 of pup mortality observed between the age of 50 days and weaning being caused by car collisions. The results suggest that population dynamics and maternal investment in the region are greatly influenced by local variables, notably the presence of an accessible food source within close proximity to the colony. Various indicators of health reflect a growing colony in good condition, and the presence of a reliable food source may influence the maximum density and carrying capacity the colony is able to sustain. However, some concerns are raised about the influence of human interactions in the region, and how this may affect mortality and colony dynamics in the future. Extra fencing along the Ohau Point colony is recommended to provide added protection from the road. Continued monitoring of mortality and health indices in the region is also recommended for comparison with other colonies as Ohau Point reaches carrying capacity and density-dependent pressures increase.

O MHC (Major Histocompatibility Complex) é um sistema genético importante para a manutenção de espécies ameaçadas, uma vez que baixa variabilidade para locos MHC tem sido associada a uma menor capacidade de resposta a doenças e diminuição do sucesso reprodutivo. Deste modo, pesquisas sobre a variabilidade genética do MHC têm demonstrado ser bastante informativas em estudos populacionais voltados para aspectos referentes à conservação. No presente trabalho foi investigada a variabilidade genética do MHC para três espécies de mamíferos marinhos (toninha, baleia franca austral e lobo marinho sul-americano) do sul do Brasil, com intensa mortalidade provocada por atividades humanas atuais ou passadas. As amostras foram coletadas de animais mortos encalhados na costa, de animais capturados acidentalmente por barcos pesqueiros, e também através de um sistema de biópsia. A região variável do exon 2 do gene DQB do MHC foi amplificada por PCR (Polymerase Chain Reaction) em 109 amostras de toninhas (Rio de Janeiro n=32, Rio Grande do Sul n=52, Argentina n=25), 35 amostras de lobo marinho sul-americano e 30 amostras de baleia franca austral, utilizando-se um par de primers heterólogos. O fragmento resultante de 172 pares de bases foi analisado quanto ao polimorfismo de seqüência através da técnica de SSCP (Polimorfismo de Conformação de Fita Simples) em todas as amostras de toninha e de lobo marinho sul-americano e 14 amostras de baleia franca austral. Dificuldades associadas à amplificação resultaram em padrões de SSCP pouco informativos para as amostras de lobo marinho sul-americano e baleia franca austral Todas as amostras de toninha apresentaram um padrão de pelo menos 4 bandas por indivíduo. As 4 bandas de um único indivíduo do Rio Grande do Sul foram seqüenciadas, tendo sido possível verificar que 2 seqüências relacionadas ao genes DQB estão sendo amplificadas com estes primers. Pelas análises de SSCP foi possível detectar ausência de variabilidade para as amostras de toninha provenientes do Rio de Janeiro e diferenciá-las da população da Argentina, que é polimórfica. A população do Rio Grande do Sul parece apresentar níveis intermediários de variação em relação aos extremos da distribuição da espécie. Analisando as três populações amostradas, conclui-se que a espécie apresenta baixos níveis de variabilidade para o loco DQB, a exemplo do que é reportado para os genes de MHC de outros mamíferos marinhos.