Comparison of the musculoskeletal forelimb anatomy of the Saimaa ( Pusa hispida saimensis ) and Baltic ringed seals ( Pusa hispida botnica )

An instrumental aerial survey was conducted in the Russian part of the Chukchi Sea and the eastern East-Siberian Sea in the spring of 2016 to investigate new technical capabilities for estimating abundance and distribution of ringed and bearded seals on the spring ice. Density of both species decreased with distance to the mainland; the largest concentrations of ringed seals were detected in coastal waters, including the Koluchinskaya and Chaunskaya Bays. Taking into account the portion of seals in the water (on average 32 %) and the portion of seals that were disturbed by the aircraft engine noise and dove (on average 30.2 % of ringed seals and 5.9 % of bearded seals), the number of ringed seals in the surveyed area was estimated as 50,839 (СI 95 %: 25,400–73,859; CV = 23.8 %), and the number of bearded seals as 14,590 (CI 95 %: 6,404–24,560; CV = 31.1 %). These estimates are considered to be biased low, primarily due to asynchronic collapse of the ringed seal snow lairs in different parts of the surveyed area, which caused a highly variable detection probability of this species that was difficult to account for.

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Variation in body size of ringed seals (Pusa hispida hispida) across the circumpolar Arctic: evidence of morphs, ecotypes or simply extreme plasticity?

Polar Research ◽

10.33265/polar.v40.5753 ◽

2021 ◽

Vol 40 ◽

Author(s):

Kit M. Kovacs ◽

John Citta ◽

Tanya Brown ◽

Rune Dietz ◽

Steve Ferguson ◽

...

Keyword(s):

Body Size ◽

The Arctic ◽

Age At Maturity ◽

Adaptation To Climate Change ◽

Eastern Canada ◽

Genetic Studies ◽

Ringed Seals ◽

Pusa Hispida ◽

Potential Adaptation ◽

Circumpolar Arctic

The ringed seal is a small phocid seal that has a northern circumpolar distribution. It has long been recognized that body size is variable in ringed seals, and it has been suggested that ecotypes that differ in size exist. This study explores patterns of body size (length and girth) and age-at-maturity across most of the Arctic subspecies’ range using morphometric data from 35 sites. Asymptotic lengths varied from 113 to 151 cm, with sites falling into five distinct size clusters (for each sex). Age-at-maturity ranged from 3.1 to 7.4 years, with sites that had early ages of sexual maturity generally having small length-at-maturity and small final body length. The sexes differed in length at some sites, but not in a consistent pattern of dimorphism. The largest ringed seals occurred in western Greenland and eastern Canada, and the smallest occurred in Alaska and the White Sea. Latitudinal trends occurred only within sites in the eastern Canadian Arctic. Girth (with length and season accounted for) was also highly variable but showed no notable spatial pattern; males tended to be more rotund than females. Genetic studies are needed, starting with the “giants” at Kangia (Greenland) and in northern Canada to determine whether they are genetically distinct ecotypes. Additional research is also needed to understand the ecological linkages that drive the significant regional size differences in ringed seals that were confirmed in this study, and also to understand their implications with respect to potential adaptation to climate change.

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Patterns of microbiome variation among infrapopulations of permanent bloodsucking parasites

10.1101/2020.05.27.118331 ◽

2020 ◽

Cited By ~ 1

Author(s):

Jorge Doña ◽

Stephany Virrueta Herrera ◽

Tommi Nyman ◽

Mervi Kunnasranta ◽

Kevin P. Johnson

Keyword(s):

Interspecific Variation ◽

Species Level ◽

Metagenomic Data ◽

Species Identity ◽

Balanced Design ◽

Microbiome Composition ◽

Qualitative And Quantitative ◽

Ringed Seals ◽

Single Host ◽

Pusa Hispida

AbstractWhile interspecific variation in microbiome composition can often be readily explained by factors such as host species identity, there is still limited knowledge of how microbiomes vary at scales lower than the species level (e.g., between individuals or populations). Here, we evaluated variation in microbiome composition of individual parasites among infrapopulations (i.e., populations of parasites of the same species living on a single host individual). To address this question, we used genome-resolved and shotgun metagenomic data of 17 infrapopulations (balanced design) of the permanent, bloodsucking seal louse Echinophthirius horridus sampled from individual Saimaa ringed seals Pusa hispida saimensis. Both genome-resolved and read-based metagenomic classification approaches consistently show that parasite infrapopulation identity is a significant factor that explains both qualitative and quantitative patterns of microbiome variation at the intraspecific level. This study contributes to the general understanding of the factors driving patterns of intraspecific variation in microbiome composition, especially of bloodsucking parasites, and has implications for understanding how well-known processes occurring at higher taxonomic levels, such as phylosymbiosis, might arise in these systems.

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Patterns of Microbiome Variation Among Infrapopulations of Permanent Bloodsucking Parasites

Frontiers in Microbiology ◽

10.3389/fmicb.2021.642543 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jorge Doña ◽

Stephany Virrueta Herrera ◽

Tommi Nyman ◽

Mervi Kunnasranta ◽

Kevin P. Johnson

Keyword(s):

Interspecific Variation ◽

Species Level ◽

Metagenomic Data ◽

Species Identity ◽

Balanced Design ◽

Microbiome Composition ◽

Qualitative And Quantitative ◽

Ringed Seals ◽

Single Host ◽

Pusa Hispida

While interspecific variation in microbiome composition can often be readily explained by factors such as host species identity, there is still limited knowledge of how microbiomes vary at scales lower than the species level (e.g., between individuals or populations). Here, we evaluated variation in microbiome composition of individual parasites among infrapopulations (i.e., populations of parasites of the same species living on a single host individual). To address this question, we used genome-resolved and shotgun metagenomic data of 17 infrapopulations (balanced design) of the permanent, bloodsucking seal louse Echinophthirius horridus sampled from individual Saimaa ringed seals Pusa hispida saimensis. Both genome-resolved and read-based metagenomic classification approaches consistently show that parasite infrapopulation identity is a significant factor that explains both qualitative and quantitative patterns of microbiome variation at the intraspecific level. This study contributes to the general understanding of the factors driving patterns of intraspecific variation in microbiome composition, especially of bloodsucking parasites, and has implications for understanding how well-known processes occurring at higher taxonomic levels, such as phylosymbiosis, might arise in these systems.

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