Colonization of the Southern Hemisphere by fur seals and sea lions (Carnivora: Otariidae) revealed by combined evidence phylogenetic and Bayesian biogeographic analysis (project)

10.7934/p529 ◽  
2014 ◽  
Author(s):  
C Churchill ◽  
W Boessenecker ◽  
T Clementz
Keyword(s):  
Southern Hemisphere ◽  
Sea Lions ◽  
Fur Seals ◽  
Biogeographic Analysis

The monophyletic origin of sea lions and fur seals (Carnivora; Otariidae) in the Southern Hemisphere

Gene ◽  
2009 ◽  
Vol 441 (1-2) ◽  
pp. 89-99 ◽  
Author(s):  
Takahiro Yonezawa ◽  
Naoki Kohno ◽  
Masami Hasegawa
Keyword(s):  
Southern Hemisphere ◽  
Monophyletic Origin ◽  
Sea Lions ◽  
Fur Seals

Taxonomy and biogeography of the Pleistocene New Zealand sea lionNeophoca palatina(Carnivora: Otariidae)

2016 ◽  
Vol 90 (2) ◽  
pp. 375-388 ◽  
Author(s):  
Morgan Churchill ◽  
Robert W. Boessenecker
Keyword(s):  
New Zealand ◽  
Southern Hemisphere ◽  
Function Analysis ◽  
Principal Component ◽  
Distinct Species ◽  
Sea Lions ◽  
The North ◽  
Fur Seals ◽  
Phylogenetic Affinities ◽  
Mammal Faunas

AbstractThe Otariidae (fur seals and sea lions) are an important and highly visible component of Southern Hemisphere marine mammal faunas. However, fossil material of Southern Hemisphere otariids is comparatively rare and often fragmentary. One exception is the Pleistocene sea lionNeophoca palatinaKing, 1983a, which is known from a nearly complete skull from the North Island of New Zealand. However, the phylogenetic affinities of this taxon are poorly known, and comparisons with other taxa have been limited. We provide an extensive redescription ofNeophoca palatinaand diagnose this taxon using a morphometric approach. Twenty measurements of the skull were collected forN. palatina, as well as for all extant Australasian otariids and several fossilNeophoca cinereaPerón, 1816. Using principal component analysis, we were able to segregate taxa by genus, andN. palatinawas found to cluster withNeophocaaccording to overall size of the skull as well as increased width of the intertemporal constriction and interorbital region.N. palatinacan be distinguished from all other Australasian otariids by its unusually broad basisphenoid. Discriminant function analysis supported referral ofNeophoca palatinatoNeophocawith very high posterior probability. These results confirm the treatment ofNeophoca palatinaas a distinct species ofNeophocaand highlight the former broad distribution and greater tolerance for colder temperatures of this genus. These results also suggest that New Zealand may have played a pivotal role in the diversification of Southern Hemisphere otariid seals.

scholarly journals Diving deep into trouble: the role of foraging strategy and morphology in adapting to a changing environment

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Monique Ladds ◽  
David Rosen ◽  
Carling Gerlinsky ◽  
David Slip ◽  
Robert Harcourt
Keyword(s):  
Foraging Strategy ◽  
Central Place ◽  
Dive Duration ◽  
Foraging Strategies ◽  
Body Morphology ◽  
Sea Lions ◽  
Fur Seals ◽  
Adequate Food ◽  
Physiological Capacity ◽  
Total Body Oxygen

Abstract Physiology places constraints on an animal’s ability to forage and those unable to adapt to changing conditions may face increased challenges to reproduce and survive. As the global marine environment continues to change, small, air-breathing, endothermic marine predators such as otariids (fur seals and sea lions) and particularly females, who are constrained by central place foraging during breeding, may experience increased difficulties in successfully obtaining adequate food resources. We explored whether physiological limits of female otariids may be innately related to body morphology (fur seals vs sea lions) and/or dictate foraging strategies (epipelagic vs mesopelagic or benthic). We conducted a systematic review of the increased body of literature since the original reviews of Costa et al. (When does physiology limit the foraging behaviour of freely diving mammals? Int Congr Ser 2004;1275:359–366) and Arnould and Costa (Sea lions in drag, fur seals incognito: insights from the otariid deviants. In Sea Lions of the World Fairbanks. Alaska Sea Grant College Program, Alaska, USA, pp. 309–324, 2006) on behavioural (dive duration and depth) and physiological (total body oxygen stores and diving metabolic rates) parameters. We estimated calculated aerobic dive limit (cADL—estimated duration of aerobic dives) for species and used simulations to predict the proportion of dives that exceeded the cADL. We tested whether body morphology or foraging strategy was the primary predictor of these behavioural and physiological characteristics. We found that the foraging strategy compared to morphology was a better predictor of most parameters, including whether a species was more likely to exceed their cADL during a dive and the ratio of dive time to cADL. This suggests that benthic and mesopelagic divers are more likely to be foraging at their physiological capacity. For species operating near their physiological capacity (regularly exceeding their cADL), the ability to switch strategies is limited as the cost of foraging deeper and longer is disproportionally high, unless it is accompanied by physiological adaptations. It is proposed that some otariids may not have the ability to switch foraging strategies and so be unable adapt to a changing oceanic ecosystem.

Species delimitation and nematode biodiversity: phylogenies rule

Nematology ◽  
2002 ◽  
Vol 4 (5) ◽  
pp. 615-625 ◽  
Author(s):  
Steven Nadler
Keyword(s):  
Species Delimitation ◽  
Sequence Data ◽  
Molecular Data ◽  
Gene Trees ◽  
California Sea Lions ◽  
Separate Species ◽  
Nucleotide Sequence Data ◽  
Sea Lions ◽  
Multiple Loci ◽  
Fur Seals

AbstractPractitioners of nematode taxonomy have rarely been explicit about what species represent or how data are being used to delimit species prior to their description. This lack of explicitness reflects the broader species problem common to all biology: there is no universally accepted idea of what species are and, as a consequence, scientists disagree on how to go about finding species in nature. However, like other biologists, nematologists seem to agree that species are real and discrete units in nature, and that they result from descent with modification. This evolutionary perspective provides a conceptual framework for nematologists to view species as independent evolutionary lineages, and provides approaches for their delimitation. Specifically, species may be delimited scientifically by methods that can test the hypothesis of lineage independence. For sequence data, such hypothesis testing should be based on sampling many individual organisms for multiple loci to avoid mistaking tokogeny and gene trees as evidence of species. Evolutionary approaches to analysing data and delimiting species avoid the inherent pitfalls in approaches that use all observed sequence differences to define species through calculation of a genetic distance. To illustrate evolutionary species delimitation, molecular data are used to test the hypothesis that hookworms parasitic in northern fur seals and in California sea lions represent separate species. The advantages and potential caveats of employing nucleotide sequence data for species delimitation are discussed, and the merits of evolutionary approaches are contrasted to inherent problems in similarity-based methods.

Fur Seals and Sea Lions

2013 ◽  
Author(s):  
Roger Kirkwood ◽  
Simon Goldsworthy
Keyword(s):  
Evolutionary Ecology ◽  
Conservation Status ◽  
Sea Lions ◽  
Australian Sea Lion ◽  
Fur Seals ◽  
Fur Seal ◽  
History Of ◽  
Near Shore ◽  
New Zealand Fur Seal ◽  
Near Extinction

Fur seals and sea lions are charismatic, large carnivores that engage us with both their skill and playful antics. Although all species in Australian waters were harvested to near extinction 200 years ago, fur seals are recovering and are now common in near-shore waters across southern Australia. Sea lions, however, are endangered. Their populations appear not to have recovered like fur seals and are declining at some locations. Fur seals and sea lions are important top level predators and play an important role in Australia’s temperate marine ecosystems. Key threats they currently face relate to human activities, particularly interactions with fisheries. This book outlines the comparative evolutionary ecology, biology, life-history, behaviour, conservation status, threats, history of human interactions and latest research on the three species of otariids that live in the waters of southern Australia: the Australian fur seal, New Zealand fur seal and Australian sea lion. It also includes brief descriptions of Antarctic and Subantarctic seals that occupy the Antarctic pack-ice and remote Australian territories of Macquarie Island and Heard Island.

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