scholarly journals Anthropozoonotic Endoparasites in Free-Ranging “Urban” South American Sea Lions (Otaria flavescens)

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Carlos Hermosilla ◽  
Liliana M. R. Silva ◽  
Mauricio Navarro ◽  
Anja Taubert
Keyword(s):  
Marine Mammals ◽  
Natural Habitat ◽  
Current Data ◽  
South American ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Carbol Fuchsin ◽  
Urban South ◽  
Faecal Samples ◽  
Free Ranging

The present study represents the first report on the gastrointestinal endoparasite fauna of a free-ranging “urban” colony of South American sea lions (Otaria flavescens) living within the city of Valdivia, Chile. A total of 40 individual faecal samples of South American sea lions were collected during the year 2012 within their natural habitat along the river Calle-Calle and in the local fish market of Valdivia. Coprological analyses applying sodium acetate acetic formalin methanol (SAF) technique, carbol fuchsin-stained faecal smears and Giardia/Cryptosporidium coproantigen ELISAs, revealed infections with 8 different parasites belonging to protozoan and metazoan taxa with some of them bearing anthropozoonotic potential. Thus, five of these parasites were zoonotic (Diphyllobothriidae gen. sp., Anisakidae gen. sp., Giardia, Cryptosporidium, and Balantidium). Overall, these parasitological findings included four new parasite records for Otaria flavescens, that is, Giardia, Cryptosporidium, Balantidium, and Otostrongylus. The current data serve as a baseline for future monitoring studies on anthropozoonotic parasites circulating in these marine mammals and their potential impact on public health.

scholarly journals Tuberculosis in wild South American sea lions Otaria flavescens stranded in Chubut, Argentina

2020 ◽  
Vol 142 ◽  
pp. 33-40
Author(s):  
C Fiorito ◽  
J Marfil ◽  
E Falzoni ◽  
M Martínez Vivot ◽  
M Zumárraga ◽  
...  
Keyword(s):  
Management Strategies ◽  
Pcr Amplification ◽  
Human Infection ◽  
South American ◽  
Free Living ◽  
Tissue Samples ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Tracheobronchial Lymph Nodes ◽  
Free Ranging

Pinniped tuberculosis, commonly caused by Mycobacterium pinnipedii, is a zoonotic disease reported in free-living and captive otariid species of the southern hemisphere. Currently, data concerning pinniped tuberculosis in South America are scarce, reinforcing the need for further studies of the disease in free-ranging pinnipeds. In this study, we investigated the presence of tuberculosis in South American sea lions Otaria flavescens (SASLs) stranded along the Chubut coastline (Argentina). Necropsies were performed in 9 SASLs, and tissue samples were collected for histopathology, bacteriology, and molecular diagnosis. Four SASLs showed enlarged tracheobronchial lymph nodes (TBLNs) with multifocal to coalescing granulomas. In these animals, a direct IS6110-PCR amplification confirmed the presence of a Mycobacterium tuberculosis complex member in TBLNs (n = 4) and lungs (n = 2), but the agent could not be further identified. In one SASL, Mycobacterium murale was isolated from lungs without lesions. This study confirms the presence of tuberculosis in SASLs from Chubut, where tourist activities promote close interaction with the animals, generating a potential risk to human health. Further research is currently focusing on addressing the prevalence of tuberculosis in wild SASLs, to assess the risk for public health and develop management strategies to avoid human infection.

scholarly journals Spontaneous Yawning and its Potential Functions in South American Sea Lions (Otaria flavescens)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elisabetta Palagi ◽  
Federico Guillén-Salazar ◽  
Clara Llamazares-Martín
Keyword(s):  
Marine Mammals ◽  
Stressful Events ◽  
South American ◽  
Social Competition ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Captive Group ◽  
The Social ◽  
Low Levels

AbstractSpontaneous yawning is a widespread behaviour in vertebrates. However, data on marine mammals are scarce. In this study, we tested some hypotheses on the functions of yawning in a captive group of South American sea lions (Otaria flavescens). According to the Dimorphism Hypothesis, species showing low levels of sexual dimorphism in canine size do not show sex differences in yawning distribution; this was supported by our findings, since yawning did not differ between the sexes. Yawning was more frequently performed during resting/sleeping contexts, thus supporting the Drowsiness Hypothesis. Yawning and self-scratching are considered reliable indicators of short-term anxiety in sea lions, since they immediately increased after conflicts both in aggressors and victims (Social Distress Hypothesis supported). In the long-term, yawning was not correlated with individuals’ dominance status, thus showing that anxiety is similarly experienced by dominants and subordinates. The last two findings can be explained by the social competition of this species, that involves individuals independently from their sex, age or ranking status. Therefore, the exposure to frequent stressful events can induce similar levels of anxiety in all the subjects (Resource Inequity Hypothesis supported). In conclusion, spontaneous yawning in sea lions seems to share similar functions with other social mammals, suggesting that this behaviour is a possible plesiomorphic trait.

scholarly journals The predation of farmed salmon by South American sea lions (Otaria flavescens) in southern Chile

2009 ◽  
Vol 67 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Juan Vilata ◽  
Doris Oliva ◽  
Maritza Sepúlveda
Keyword(s):  
Prey Size ◽  
South American ◽  
Southern Chile ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Farmed Salmon ◽  
South American Sea Lion ◽  
Autumn And Winter ◽  
Strong Suspicion

Abstract Vilata, J., Oliva, D., and Sepúlveda, M. 2010. The predation of farmed salmon by South American sea lions (Otaria flavescens) in southern Chile. – ICES Journal of Marine Science, 67: 475–482. The South American sea lion Otaria flavescens is abundant off southern Chile. Because Chilean salmon farming has experienced an explosive growth in the past two decades, interactions between O. flavescens and this industry have increased. Fieldwork, including in situ behavioural observations, was carried out at three salmon farms off southern Chile from May to July 2008. The aim was to analyse possible patterns in the interactions and to evaluate whether they were influenced by the endogenous circa-rhythms of the species, prey size, tidal flux, and the use of an acoustic harassment device (AHD). The results showed that the attacks by O. flavescens followed seasonal patterns, with salmon predated more in autumn and winter, and daily patterns, with more interactions at night. In addition, attacks were more frequent on larger salmon, suggesting the existence of a prey-size preference. More sea lions were sighted at the ebb and flow tide peaks, when currents are stronger, suggesting that currents linked to tidal flux might facilitate the access of the sea lions to the farmed salmon. Although the use of AHDs appeared positive at one site, there is a strong suspicion that their efficacy may be site-specific.

First observations of operational interactions between bottom-trawling fisheries and South American sea lion, Otaria flavescens in south-central Chile

2012 ◽  
Vol 93 (2) ◽  
pp. 489-494 ◽  
Author(s):  
Pablo Reyes ◽  
Rodrigo Hucke-Gaete ◽  
Juan Pablo Torres-Florez
Keyword(s):  
South American ◽  
The South ◽  
Sea Lion ◽  
Central Chile ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
South American Sea Lion ◽  
South Central ◽  
By Catch ◽  
Working Day

This paper presents results of a study conducted on the trawling industrial fishery fleet of Merluccius gayi in south-central Chile, and the resulting interactions with the South American sea lion (Otaria flavescens). This study is based on observations made during September 2004, when incidental sea lion catch in the trawls was 6.3 sea lions/working day (1.2 sea lions/trawl−1). A total of 82 animals were incidentally caught, of which 12 were found dead, and the 70 remaining suffered from internal bleeding and/or fractures as a result of their capture. 83.3% of the fatalities occurred during nocturnal trawls, which comprise 30% of all observed trawls. Possible mechanisms of sea lion take are discussed. This note presents the first records of sea lions incidental by-catch by the trawler fleet along the south-east Pacific coast of Chile.

Transmission of Corynosoma australe (Acanthocephala: Polymorphidae) from fishes to South American sea lions Otaria flavescens in Patagonia, Argentina

2019 ◽  
Vol 118 (2) ◽  
pp. 433-440 ◽  
Author(s):  
Jesús S. Hernández-Orts ◽  
Francisco E. Montero ◽  
Néstor A. García ◽  
Enrique A. Crespo ◽  
Juan A. Raga ◽  
...  
Keyword(s):  
South American ◽  
Otaria Flavescens ◽  
Sea Lions

South American sea lions Otaria byronia as biological samplers of local cephalopod fauna in the Patagonian shelf marine ecosystem

2019 ◽  
Vol 99 (06) ◽  
pp. 1459-1463
Author(s):  
R. L. Bustos ◽  
G. A. Daneri ◽  
E. A. Varela ◽  
A. Harrington ◽  
A. V. Volpedo ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Marine Ecosystem ◽  
Isotopic Signature ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
South American ◽  
Sea Lions ◽  
Patagonian Shelf ◽  
Important Prey ◽  
Top Predators

AbstractCephalopods are important prey in the diet of top predators, such as marine mammals and seabirds. However, detailed information on their trophic relationships in the Patagonian marine ecosystem is scarce, including those cephalopod species with commercial interest. The aims of this study were to evaluate the composition of the cephalopod component in the diet of Otaria byronia and determine the habitat use and trophic levels of their main cephalopod prey by measuring the stable isotopic signature of cephalopod beaks. Between May 2005 and February 2009, fresh faecal samples were collected from two sea lions rookeries in San Matias Gulf. Cephalopods occurred in 39.4% of the 1112 samples collected during the whole period of study. The dominant prey species was Octopus tehuelchus, which occurred in 45.8% of scats containing cephalopod remains, and represented 58.7% in terms of numerical abundance and 52.0% in mass of cephalopods consumed. The second species most consumed was the myopsid Doryteuthis gahi. The significant higher δ15N values of O. tehuelchus beaks in comparison with those of D. gahi showed that these two species have different trophic levels while occupying similar habitat (δ13C values) in neritic waters of the Patagonian shelf.

Reference Intervals of Mineral Elements in Plasma of Anesthetized Free-Ranging Adult Females of South American Sea Lion, Otaria flavescens

2016 ◽  
Vol 174 (2) ◽  
pp. 325-327
Author(s):  
Paula S. Polizzi ◽  
L. N. Chiodi Boudet ◽  
A. Ponce de León ◽  
M. Quiroga ◽  
D. H. Rodríguez ◽  
...  
Keyword(s):  
Mineral Elements ◽  
Reference Intervals ◽  
South American ◽  
Sea Lion ◽  
Otaria Flavescens ◽  
South American Sea Lion ◽  
Adult Females ◽  
Free Ranging
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