Studying South American fur seals in northern Patagonia, Chile

10.18258/3180 ◽  
2014 ◽  
Author(s):  
Mauricio Seguel Mauricio Seguel
Keyword(s):  
South American ◽  
Northern Patagonia ◽  
Fur Seals

Intestinal helminth fauna of the South American sea lion Otaria flavescens and fur seal Arctocephalus australis from northern Patagonia, Argentina

2012 ◽  
Vol 87 (3) ◽  
pp. 336-347 ◽  
Author(s):  
J.S. Hernández-Orts ◽  
F.E. Montero ◽  
A. Juan- García ◽  
N.A. García ◽  
E.A. Crespo ◽  
...  
Keyword(s):  
Helminth Fauna ◽  
Intestinal Helminth ◽  
Type I ◽  
South American ◽  
Component Community ◽  
New Host ◽  
Otaria Flavescens ◽  
Sea Lions ◽  
Northern Patagonia ◽  
Fur Seals

AbstractWe 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 acanthocephalan (Corynosoma australe). In addition, third-stage larvae of 2 nematodes (Contracaecum sp. and Anisakis sp. type I) and 3 juvenile acanthocephalans (Andracantha sp., Profilicollis chasmagnathi and Corynosoma cetaceum) were also collected. Andracantha sp., C. ogmorhini s.s. and P.chasmagnathi represent new host records. A total of 1516 helminth specimens were collected from fur seals. Gravid individuals were represented by three species of parasites, namely, Diphyllobothrium spp., C. ogmorhini s.s. and C. australe. In addition, larvae of Contracaecum sp. and P. cattani, juveniles of C. cetaceum and immature cestodes (Tetrabothriidae gen. sp.) were also collected. Corynosoma australe was the most prevalent and abundant parasite in both hosts, accounting for >90% of all specimens. Sea lions and furs seals from northern Patagonia harbour the intestinal helminth communities that could be predicted for otariids, i.e. the combination of species of the genera Corynosoma, Diphyllobothrium, Pseudoterranova, Contracaecum and, in pups, Uncinaria. Additionally, both species of otariid are apparently unsuitable hosts (i.e. non-hosts) for as many as five parasite taxa. The inclusion or exclusion of these species affects estimation of species richness at both component community (11 versus 6 species in sea lions; 7 versus 3 species in fur seals) and infracommunity (mean: 3.1 versus 2.6 in sea lions; 2.2 versus 1.7 species) levels. Information about the reproductive status of helminth species is often lacking in parasitological surveys on otariids and other marine vertebrates, but it is of significance to improve precision in parascript studies or ecological meta-analyses.

First detection of plastic microfibers in a wild population of South American fur seals (Arctocephalus australis) in the Chilean Northern Patagonia

2018 ◽  
Vol 136 ◽  
pp. 50-54 ◽  
Author(s):  
D.J. Perez-Venegas ◽  
M. Seguel ◽  
H. Pavés ◽  
J. Pulgar ◽  
M. Urbina ◽  
...  
Keyword(s):  
Wild Population ◽  
South American ◽  
Northern Patagonia ◽  
Fur Seals

Segregation of diets by sex and individual in South American fur seals

2021 ◽  
Author(s):  
Renan C. de Lima ◽  
Valentina Franco-Trecu ◽  
Thayara S. Carrasco ◽  
Pablo Inchausti ◽  
Eduardo R. Secchi ◽  
...  
Keyword(s):  
South American ◽  
Fur Seals

Oceanographic factors influencing the distribution of South American fur seal, Arctocephalus australis around the Falkland Islands before the breeding season

2009 ◽  
Vol 89 (8) ◽  
pp. 1597-1600 ◽  
Author(s):  
Vladimir Laptikhovsky
Keyword(s):  
Prey Species ◽  
Falkland Islands ◽  
South American ◽  
Important Food ◽  
Factors Influencing ◽  
South West ◽  
Fur Seals ◽  
Fur Seal ◽  
Important Food Source ◽  
Productive Zone

Distribution of fur seals Arctocephalus australis has been studied in October 2007 on the western, southern and eastern Falkland shelves during the survey of spawning grounds of the red cod, Salilota australis. Fur seals presence/absence, numbers and sex were recorded at every oceanographic station. Animals were found foraging on the shelf edge south-west of the islands, in a productive zone with quasi-stationary eddies at a periphery of upwelling. It was also the zone of maximum abundance of lobster-krill, Munida spp.—an important food source of fur seals and aggregations of both red cod and blue whiting, Micromesistius australis. No fur seals were found in waters of the relative cold and saline Falkland Current as well as in the relatively warm, fresh and oxygen-rich waters of Argentine Drift. It allows supposing that position and extension of the foraging grounds are caused by oceanographic features determining distribution of prey species.

Parasitism Elicits a Stress Response That Allocates Resources for Immune Function in South American Fur Seals (Arctocephalus australis)

2019 ◽  
Vol 92 (3) ◽  
pp. 326-338 ◽  
Author(s):  
Mauricio Seguel ◽  
Diego Perez-Venegas ◽  
Josefina Gutierrez ◽  
Daniel E. Crocker ◽  
Eugene J. DeRango
Keyword(s):  
Stress Response ◽  
Immune Function ◽  
South American ◽  
Fur Seals

Recovery of the South American sea lion (Otaria flavescens) population in northern Patagonia

2004 ◽  
Vol 61 (9) ◽  
pp. 1681-1690 ◽  
Author(s):  
Silvana Laura Dans ◽  
Enrique Alberto Crespo ◽  
Susana Noemí Pedraza ◽  
Mariano Koen Alonso
Keyword(s):  
Survival Rates ◽  
South American ◽  
The South ◽  
Sea Lion ◽  
Otaria Flavescens ◽  
Northern Patagonia ◽  
Rates Of Change ◽  
South American Sea Lion ◽  
Rate Of Increase ◽  
Peripheral Areas

The size of and trend in the South American sea lion (Otaria flavescens) population located in northern Patagonia were estimated and changes in the distribution, size, and structure of individual sites were analyzed during the period 1983–2002. Total counts were made during the reproductive season. Regression models were used to analyze the trend. Pups represented around 40% of the animals counted. The annual rates of change for pups and nonpups were not significantly different (p > 0.05, n = 7), although some rookeries showed higher rates of change for pups than for nonpups. Pup numbers have been increasing at the rate of 3.4% per year at the oldest rookeries, but the rate of increase was higher at new rookeries. Using Bayes' methods, the precision of the estimates and the contribution to the abundance of each rookery produced an alternative estimate of the trend in pup numbers in 5.7%. The key in the recovery of this population includes higher survival rates of juveniles combined with increased available habitat for newly reproducing individuals. This process led to the occupancy of new areas for hauling out and breeding. This hypothesis could explain the higher rates of increase in pups in peripheral areas while reproductive rates remain unchanged.

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