Phocid Research Articles

A late surviving Pliocene seal from high latitudes of the North Atlantic realm: the latest monachine seal on the southern margin of the North Sea.

BackgroundThe family of true seals, the Phocidae, is subdivided into two subfamilies: the southern Monachinae, and the northern Phocinae, following the subfamilies’ current distribution: extant Monachinae are largely restricted to the (sub-)Antarctic and the eastern Pacific, with historical distributions of the monk seals of the genus Monachus in the Caribbean, the Mediterranean and around Hawaii; and Phocinae to the northern temperate and Arctic zones. However, the fossil record shows that Monachinae were common in the North Atlantic realm during the late Miocene and early Pliocene. Until now, only one late Pliocene record is known from the Mediterranean, Pliophoca etrusca from Tuscany, Italy, but none from farther north in the North Atlantic.MethodsWe present the description of one partial phocid humerus collected in the early 20th century from the Antwerp area (Belgium), with an assessment of its stratigraphic origin using data from the literature.ResultsThe studied humerus was recovered during construction works at the former Lefèvre dock in the Antwerp harbour (currently part of the America dock). Combining the information associated to the specimen with data from the literature and from local boreholes, the upper Pliocene Lillo Formation is ascertained as the lithological unit from which the specimen originates. Morphologically, among other features the shape of the deltopectoral crest and the poor development of the supinator crest indicates a monachine attribution for this specimen. The development of the deltopectoral crest is closer to the condition in extant Monachinae than in extinct Monachinae.DiscussionThe presented specimen most likely represents a monachine seal and a literature study clearly shows that it came from the latest early to late Pliocene Lillo Formation. This would be the first known monachine specimen from the latest early to late Pliocene of the North Sea, and more broadly from the northern part of the North Atlantic realm. This humerus differs from the humerus of P. etrusca and suggests a higher diversity of Monachinae in the latest early to late Pliocene than previously assumed.

Opportunistic ship-based census of pack ice seals in eastern Weddell Sea, Antarctica

The distribution, density and percentage contribution of pack ice pinnipeds during ship-board censuses in the eastern Weddell Sea in summer 2015/2016 are presented. Of the four true pack ice seal species encountered, crabeater seals predominated. Despite the low survey effort, Ross seals continued to be relatively abundant in the pack ice off the Princess Martha Coast in mid-January 2016, similar to the situation here in the 1970s. Censusing of Ross seals is ideally carried out in late January/early February when the species’ haulout probability is at its maximum and the seals are gathered in the limited summer pack ice to moult.

The production and reception of underwater sound in Hawaiian monk seals (Neomonachus schauinslandi)

The endangered Hawaiian monk seal is a primitive phocid (true) seal endemic to the tropical Hawaiian Islands. At present, there is a lack of substantive bioacoustic information available for this species, with no formal descriptions of underwater vocalizations and limited data concerning underwater hearing. To address these knowledge gaps, we are working to better understand species-typical auditory capabilities and sound production by thoroughly evaluating a single individual living in human care. A mature male monk seal was trained to perform an auditory go/no-go signal detection task in water. Detection thresholds were measured for narrowband tones across the frequency range of hearing to generate a full underwater audiogram. Additionally, an acoustic recorder was placed in this monk seal’s living enclosure for a full year, enabling characterization of his underwater repertoire and seasonal trends in vocal behavior. This study presents the first examination of underwater vocalizations in Hawaiian monk seals, provides insight into the perceptual abilities of this species and the evolution of underwater hearing within the phocid lineage, and enables improved assessments of noise effects on these vulnerable seals. [Work supported by Navy’s Living Marine Resources Program.]

Generalized Osteosclerotic Condition in the Skeleton of Nanophoca vitulinoides, a Dwarf Seal from the Miocene of Belgium

In the fossil record, it has been shown that various clades of secondarily aquatic tetrapods experienced an initial densification of their bones in the early stages of their evolution, and developed spongier and lighter bones only later in their evolution, with the acquisition of more efficient swimming modes. Although the inner bone structure of most secondarily aquatic tetrapods has already been studied, no research hitherto focused on true seals, or Phocidae. However, preliminary observations previously made on a Miocene species, Nanophoca vitulinoides, suggested that this taxon showed pronounced specialization of bone structure as compared to other seals. This feature justifies a specific comparative study, which is the purpose of this article. Microanatomical analysis of bones of N. vitulinoides shows compactness values nearing 100%, which is much higher than in other semi-aquatic mammals, pinnipeds included. Osteohistological analyses show virtually complete remodeling of the medullary territory by Haversian substitution. Extreme bone compactness locally resulted from an imbalance, towards reconstruction, of this process. Cortical regions were less intensely remodeled. In a number of specimens, the cortex shows clear growth marks as seasonal lines of arrested growth. The results suggest that, despite the extreme compactness of long bones of N. vitulinoides and the small size of this taxon, the growth rate of the cortex, and that of the bones in general, did not differ strongly from that of other, larger phocids. Extreme skeletal compaction and densification must have increased body density in Nanophoca. Consequently, speed, acceleration, and maneuverability must have been low, and this taxon was most likely a near-shore bottom-dwelling seal. Consequently, dietary preferences were most likely oriented towards benthic food sources.

A critical revision of the fossil record, stratigraphy and diversity of the Neogene seal genus Monotherium (Carnivora, Phocidae).

Historically, Monotherium had been one of the few genera of extinct Phocidae (true seals) that served as a wastebin taxon. Consequently, it did neither aid in understanding phylogenetic relationships of extinct Phocidae, nor in understanding seal diversity in deep time. This urged the reassessment of the genus. Before our review, Monotherium included five different species: Monotherium aberratum, Monotherium affine, and Monotherium delognii from Belgium; Monotherium gaudini from Italy; and Monotherium? wymani from the east coast USA. In this work we redescribe the fossil record of the genus, retaining the type species M. delognii. Monotherium aberratum and M. affine are reassigned to the new phocine genus Frisiphoca. Monotherium gaudini is renamed and considered a stem-monachine (Noriphoca gaudini). The holotype of the monachine M.? wymani requires further study pending the discovery of new fossil material that could be attributed to the same taxon. Reinvestigating the stratigraphic context reveals that N. gaudini most likely represents one of the two oldest named phocid seals, or even the oldest, dated to the late Oligocene–earliest Miocene. Our results allow questioning the widespread idea that Phocidae originated in the western Atlantic and better appreciate their palaeobiogeography during the late Oligocene–Miocene interval in the North Atlantic realm.

Comparative adsorption profiles of basal lamina proteome and gingival cells onto dental and titanium surfaces

Titanium (Ti) dental implants are susceptible to bacterial infections and failure due to lack of proper epithelial seal. Epithelial cells establish a strong epithelial seal around natural teeth by the deposition of basal lamina (BL) proteins that adsorb on the tooth surface. This seal can even be re-established onto cementum or dentin following injury or periodontal therapy. However, it is unclear how tooth surfaces promote this cell attachment and protein adsorption. Understanding the interactions between BL proteins and epithelial cells with dentin and Ti will facilitate the development of implant surfaces that promote the formation of an epithelial seal and improve the success of periodontal therapy and wound healing on natural teeth. To study these interactions, we used a surface proteomic approach to decipher the adsorption profile of BL proteins onto Ti and dentin, and correlated these adsorption profiles with in vitro interactions of human gingival fibroblasts and epithelial cells. Results showed that dentin adsorbed higher amounts of key BL proteins, particularly laminin and nidogen-1, and promoted more favorable interactions with epithelial cells than Ti. Next, dentin specimens were deproteinized or partially demineralized to determine if its mineral or protein component was responsible for BL adsorption and cell attachment. Deproteinized (mineral-rich) and partially demineralized (protein-rich) dentin specimens revealed BL proteins (i.e. laminin and nidogen-1) and epithelial cells interact preferentially with dentinal proteins rather than dentin mineral. These findings suggest that, unlike Ti, dentin and, in particular, dentinal proteins have a selective affinity to BL proteins that enhance epithelial cell attachment. Statement of SignificanceIt is remains unclear why natural teeth, unlike titanium dental implants, promote the formation of an epithelial seal that protects them against the external environment. This study used a surface screening approach to analyze the adsorption of proteins produced by epithelial tissues onto tooth-dentin and titanium surfaces, and correlate it with the behaviour of cells. This study shows that tooth-dentin, in particular its proteins, has a higher selective affinity to certain adhesion proteins, and subsequently allows more favourable interactions with epithelial cells than titanium. This knowledge could help in developing new approaches for re-establishing and maintaining the epithelial seal around teeth, and could pave the way for developing implants with surfaces that allow the formation of a true epithelial seal.

Clawed forelimbs allow northern seals to eat like their ancient ancestors.

Streamlined flippers are often considered the defining feature of seals and sea lions, whose very name ‘pinniped’ comes from the Latin pinna and pedis, meaning ‘fin-footed’. Yet not all pinniped limbs are alike. Whereas otariids (fur seals and sea lions) possess stiff streamlined forelimb flippers, phocine seals (northern true seals) have retained a webbed yet mobile paw bearing sharp claws. Here, we show that captive and wild phocines routinely use these claws to secure prey during processing, enabling seals to tear large fish by stretching them between their teeth and forelimbs. ‘Hold and tear’ processing relies on the primitive forelimb anatomy displayed by phocines, which is also found in the early fossil pinniped Enaliarctos. Phocine forelimb anatomy and behaviour therefore provide a glimpse into how the earliest seals likely fed, and indicate what behaviours may have assisted pinnipeds along their journey from terrestrial to aquatic feeding.

Brucella Antibodies in Alaskan True Seals and Eared Seals—Two Different Stories

Brucella pinnipedialis was first isolated from true seals in 1994 and from eared seals in 2008. Although few pathological findings have been associated with infection in true seals, reproductive pathology including abortions, and the isolation of the zoonotic strain type 27 have been documented in eared seals. In this study, a Brucella enzyme-linked immunosorbent assay (ELISA) and the Rose Bengal test (RBT) were initially compared for 206 serum samples and a discrepancy between the tests was found. Following removal of lipids from the serum samples, ELISA results were unaltered while the agreement between the tests was improved, indicating that serum lipids affected the initial RBT outcome. For the remaining screening, we used ELISA to investigate the presence of Brucella antibodies in sera of 231 eared and 1,412 true seals from Alaskan waters sampled between 1975 and 2011. In eared seals, Brucella antibodies were found in two Steller sea lions (Eumetopias jubatus) (2%) and none of the 107 Northern fur seals (Callorhinus ursinus). The low seroprevalence in eared seals indicate a low level of exposure or lack of susceptibility to infection. Alternatively, mortality due to the Brucella infection may remove seropositive animals from the population. Brucella antibodies were detected in all true seal species investigated; harbor seals (Phoca vitulina) (25%), spotted seals (Phoca largha) (19%), ribbon seals (Histriophoca fasciata) (16%), and ringed seals (Pusa hispida hispida) (14%). There was a low seroprevalence among pups, a higher seroprevalence among juveniles, and a subsequent decreasing probability of seropositivity with age in harbor seals. Similar patterns were present for the other true seal species; however, solid conclusions could not be made due to sample size. This pattern is in accordance with previous reports on B. pinnipedialis infections in true seals and may suggest environmental exposure to B. pinnipedialis at the juvenile stage, with a following clearance of infection. Furthermore, analyses by region showed minor differences in the probability of being seropositive for harbor seals from different regions regardless of the local seal population trend, signifying that the Brucella infection may not cause significant mortality in these populations. In conclusion, the Brucella infection pattern is very different for eared and true seals.

Rapid changes in Atlantic grey seal milk from birth to weaning \u2013 immune factors and indicators of metabolic strain

True seals have the shortest lactation periods of any group of placental mammal. Most are capital breeders that undergo short, intense lactations, during which they fast while transferring substantial proportions of their body reserves to their pups, which they then abruptly wean. Milk was collected from Atlantic grey seals (Halichoerus grypus) periodically from birth until near weaning. Milk protein profiles matured within 24 hours or less, indicating the most rapid transition from colostrum to mature phase lactation yet observed. There was an unexpected persistence of immunoglobulin G almost until weaning, potentially indicating prolonged trans-intestinal transfer of IgG. Among components of innate immune protection were found fucosyllactose and siallylactose that are thought to impede colonisation by pathogens and encourage an appropriate milk-digestive and protective gut microbiome. These oligosaccharides decreased from early lactation to almost undetectable levels by weaning. Taurine levels were initially high, then fell, possibly indicative of taurine dependency in seals, and progressive depletion of maternal reserves. Metabolites that signal changes in the mother’s metabolism of fats, such as nicotinamide and derivatives, rose from virtual absence, and acetylcarnitines fell. It is therefore possible that indicators of maternal metabolic strain exist that signal the imminence of weaning.

Characterization of seal whisker morphology: implications for whisker-inspired flow control applications

Seals with beaded whiskers—the majority of true seals (Phocids)—are able to trace even minute disturbance caused by prey fish in the ambient flow using only sensory input from their whiskers. The unique three-dimensional undulating morphology of seal whiskers has been associated with their capability of suppressing vortex-induced vibration and reducing drag. The exceptional hydrodynamic traits of seal whiskers are of great interest in renovating the design of aero-propulsion flow components and high-sensitivity flow sensors. It is essential to have well-documented data of seal whisker morphology with statistically meaningful generalization, as the solid foundation for whisker-inspired flow control applications. However, the available whisker morphology data is either incomplete, with measurements of only a few key parameters, or based on a very limited sample size in case studies. This work characterizes the morphology of 27 beaded seal whiskers (harbor seal and elephant seal), using high-resolution computer-tomography scanning at NASA’s Glenn Research Center in Cleveland, OH. Over two thousand cross-sectional slices for every individual whisker sample are reconstructed, to generate three-dimensional morphology. This is followed by detailed statistical analysis of a set of key parameters, under an established framework (Hanke et al 2010 J. Exp. Biol. 213 2665–72). While the length parameters are generally consistent with previous studies, we note that the angle of incidence of elliptical cross-sections varies in a wide range, with a majority falling between and . Angles of incidence at both peaks and troughs appear to roughly follow a Gaussian distribution, but no clear preference of orientation is identified. We discuss the current knowledge of whisker-inspired flow studies, focusing on choices of morphology parameters. The new understanding of whisker morphology can better inform future design of high-sensitivity flow sensors and aero-propulsion flow structures.

New Miocene Monachinae from the Western Shore of the Chesapeake Bay (Maryland, USA)

Abstract The Family Phocidae includes four subfamilies (Phocinae, Monachinae, Cystophorinae, and Devinophocinae) consisting of mediumto large-sized mammals that possess distinctive adaptations to semi-aquatic life. In the Miocene of the Chesapeake Group, only two subfamilies of the Family Phocidae were identified: Phocinae and Monachinae. Leptophoca, a representative of the subfamily Phocinae, appears on the eastern shore of the North Atlantic around 16 million years ago. Recently, two new monachine species, the larger Terranectes magnus (n. gen., n. sp.) and the medium-sized T. parvus (n. sp.), were recorded in the Upper Miocene of the Chesapeake Group in the Eastover Formation (7.0–6.0 Ma) and St. Marys Formation (10.0-8.0 Ma). These two distinct subfamilies of seals indicate a well-marked divergence between phocines and monachines, much earlier than 18 million years ago, as previously suggested. The Eastover Formation was deposited in a shallow embayment that covered southern Maryland, the coastal plain of Virginia, and the northeastern corner of North Carolina. The geologically older St. Marys Formation represents a tide-influenced coastal environment, with low-salinity estuaries. There was a sharp temperature decrease in the Late Miocene, indicated by a shift to a cooler-water fish fauna during St. Marys time. The Eastover Formation reflects warmer waters with relatively strong currents, significant shoals, barriers, and varied depths. Fossil evidence of earlier seals suggests that phocids originated in the North Atlantic and otarioids in the North Pacific. True seals diverged from ancient Carnivora in the early Oligocene (or earlier) in the Paratethyan / Mediterranean Basins, spread widely during the Middle Miocene and crossed westward across the Atlantic Ocean, before dispersing in the eastern United States by the Early Pliocene.

Влияние оптических характеристик среды на цветовое зрение настоящих тюленей

Влияние оптических характеристик среды на цветовое зрение настоящих тюленей

A (in)eficácia dos selos verdes sobre o comportamento dos consumidores: um estudo experimental

The objective of the study was to analyze consumers' perceptions about green seals, according to how well known these seals are and to their own profile of green consumption. Therefore, a theoretical reference was made on sustainable consumption, as well as on the application of green seals in the perspective of green marketing. The method adopted was a hypothetical-deductive approach, carried out through two experiments (one online and the other face-to-face), both with factorial design 2 (true and well-known green seal versus false seal and nothing known) x 2 very sustainable versus low sustainable consumer profile). In view of the results obtained, four main discussions could be made, such as the possibility of greenwashing due to the clear mention of environmental aspects, either in relation to the seal itself or to the statements underlying it, the ineffectiveness of adopting green seals and influence of this ineffectiveness even in consumers who reported having a more sustainable consumption profile.

Feel the beat: Music exploits our brain's ability to predict and the dopamine-reward system to instill pleasure.

Music is universally cherished across humanity. Every culture has its songs and dances, everywhere in the world people listen to music; even small children clap their hands and move to the rhythm of the beat. Music moves us in every sense of the word. We just do not know why. The musical abilities of humankind have puzzled scientists for centuries, and Charles Darwin ranked them as “one of the most mysterious with which he is endowed”. Why do we make music, why do we like it, and how do we even perceive it? > The musical abilities of humankind have puzzled scientists for centuries, and Charles Darwin ranked them as “one of the most mysterious with which he is endowed”. “Music is art in time”, said Peter Vuust, a neuroscientist and music theoretician at Aarhus University in Denmark. Perceiving music has much to do with our sense of time and anticipation. Music is never perceived instantly: We need a few notes or beats before we detect a rhythm, and with the last few notes in mind, we anticipate what will happen next. Mostly, these anticipations will be met, but sometimes not. “Music plays with predictions, and this is what makes it so interesting to science”, explained Vuust, because it helps to investigate the brain's predictive timing mechanisms. “Predictive coding” is a conceptual framework of how the brain makes forecasts. It predicts incoming sensory information based on experience and context. This prediction is tightly coupled to the release of dopamine, the neurotransmitter of reward. In addition to predicting what will happen next, it is just as important to know exactly when it will happen, and an analogous system of “predictive timing” takes on this task. A school of fish or a flock of birds all turning at the same time, a dog …

Animals

Book Review| October 01 2016 Animals Seal. By Victoria Dickenson. 2016. Reaktion Books. (ISBN: 978-1-78023-489-2). 224 pp. Paperback. $19.95. Sara Fox Sara Fox 1Academy of Science and Technology The Woodlands, TX 77384 sfox@conroeisd.net Search for other works by this author on: This Site PubMed Google Scholar The American Biology Teacher (2016) 78 (8): 689–690. https://doi.org/10.1525/abt.2016.78.8.689b Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Sara Fox; Animals. The American Biology Teacher 1 October 2016; 78 (8): 689–690. doi: https://doi.org/10.1525/abt.2016.78.8.689b Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentThe American Biology Teacher Search Seal is the latest release in the Animal series published by Reaktion Books, and the second authored by Victoria Dickenson. The book begins with a review of the evolutionary history of this playful species and then moves into the long and complicated relationship between seals and humans, from the folklore of the selkies to the controversial but historic seal hunts. Dickenson describes pinnipeds, the clade of carnivorous, semiaquatic mammals that includes the Phocidae, or true seals, which are the focus of this book. If you have not spent much time along a coast where seals are common, then the pinniped you are likely most familiar with is actually a sea lion. “The otariids – fur seals and sea lions – are also distinguished by their possession of pinnae, or outer ears. The walrus and the phocids have none, and the ‘true’ seals are thus commonly known as the ‘earless’ seals”... You do not currently have access to this content.

Re-Evaluation of Morphological Characters Questions Current Views of Pinniped Origins

Abstract The origin of pinnipeds has been a contentious issue, with opposite sides debating monophyly or diphyly. This review uses evidence from the fossil record, combined with comparative morphology, molecular and cytogenetic investigations to evaluate the evolutionary history and phylogenetic relationships of living and fossil otarioid and phocoid pinnipeds. Molecular investigations support a monophyletic origin of pinnipeds, but disregard vital morphological data. Likewise, morphological studies support diphyly, but overlook molecular analyses. This review will demonstrate that a monophyletic origin of pinnipeds should not be completely accepted, as is the current ideology, and a diphyletic origin remains viable due to morphological and paleobiological analyses. Critical examination of certain characters, used by supporters of pinniped monophyly, reveals different polarities, variability, or simply convergence. The paleontological record and our morphological analysis of important characters supports a diphyletic origin of pinnipeds, with otarioids likely arising in the North Pacific from large, bear-like animals and phocids arising in the North Atlantic from smaller, otter-like ancestors. Although members of both groups are known by Late Oligocene time, each developed and invaded the aquatic environment separately from their much earlier, common arctoid ancestor. Therefore, we treat the superfamily Otarioidea as being monophyletic, including the families Enaliarctidae, Otariidae (fur seals/sea lions), Desmatophocidae, and Odobenidae (walruses and extinct relatives), and the superfamily Phocoidea as monophyletic, including only the family Phocidae, with four subfamilies (Devinophocinae, Phocinae, Monachinae, and Cystophorinae).

Experimental Challenge of Atlantic Cod (Gadus morhua) with a Brucella pinnipedialis Strain from Hooded Seal (Cystophora cristata).

Pathology has not been observed in true seals infected with Brucella pinnipedialis. A lack of intracellular survival and multiplication of B. pinnipedialis in hooded seal (Cystophora cristata) macrophages in vitro indicates a lack of chronic infection in hooded seals. Both epidemiology and bacteriological patterns in the hooded seal point to a transient infection of environmental origin, possibly through the food chain. To analyse the potential role of fish in the transmission of B. pinnipedialis, Atlantic cod (Gadus morhua) were injected intraperitoneally with 7.5 x 107 bacteria of a hooded seal field isolate. Samples of blood, liver, spleen, muscle, heart, head kidney, female gonads and feces were collected on days 1, 7, 14 and 28 post infection to assess the bacterial load, and to determine the expression of immune genes and the specific antibody response. Challenged fish showed an extended period of bacteremia through day 14 and viable bacteria were observed in all organs sampled, except muscle, until day 28. Neither gross lesions nor mortality were recorded. Anti-Brucella antibodies were detected from day 14 onwards and the expression of hepcidin, cathelicidin, interleukin (IL)-1β, IL-10, and interferon (IFN)-γ genes were significantly increased in spleen at day 1 and 28. Primary mononuclear cells isolated from head kidneys of Atlantic cod were exposed to B. pinnipedialis reference (NCTC 12890) and hooded seal (17a-1) strain. Both bacterial strains invaded mononuclear cells and survived intracellularly without any major reduction in bacterial counts for at least 48 hours. Our study shows that the B. pinnipedialis strain isolated from hooded seal survives in Atlantic cod, and suggests that Atlantic cod could play a role in the transmission of B. pinnipedialis to hooded seals in the wild.

Seals and sea lions are what they eat, plus what? Determination of trophic discrimination factors for seven pinniped species

Mixing models are a common method for quantifying the contribution of prey sources to the diet of an individual using stable isotope analysis; however, these models rely upon a known trophic discrimination factor (hereafter, TDF) that results from fractionation between prey and animal tissues. Quantifying TDFs in captive animals is ideal, because diet is controlled and the proportional contributions and isotopic values of all prey items are known. To calculate TDFs for the Hawaiian monk seal, northern elephant seal, bearded seal, ringed seal, spotted seal, harbor seal, and California sea lion, we obtained whiskers, serum, plasma, red blood cells, and prey items from nine captive individuals. We obtained δ(13) C and δ(15) N values using continuous-flow isotope-ratio mass spectrometry. The average δ(13) C and δ(15) N values from bulk and lipid-corrected prey from the diet were subtracted from the δ(13) C and δ(15) N values of each blood and whisker sample to calculate tissue-specific TDFs for each individual (∆(13) C or ∆(15) N). The ∆(13) C values ranged from +1.7 to +3.2‰ (bulk prey) and from +0.8 to +1.9‰ (lipid-corrected prey) for the various blood components, and from +3.9 to +4.6‰ (bulk prey) or +2.6 to +3.9‰ (lipid-corrected prey) for whiskers. The ∆(15) N values ranged from +2.2 to +4.3‰ for blood components and from +2.6 to +4.0‰ for whiskers. The TDFs tended to group by tissue, with whiskers having greater ∆(13) C values than blood components. In contrast, the ∆(15) N values were greater in serum and plasma than in red blood cells and whiskers. By providing the first TDF values for five seal species (family Phocidae) and one otariid species (family Otariidae), our study facilitates more accurate mixing models for these species. These values are particularly important for critically endangered Hawaiian monk seals and the three Arctic seal species (bearded, ringed, and spotted) that are faced with a rapidly changing environment.

A new dwarf seal from the late Neogene of South America and the evolution of pinnipeds in the southern hemisphere

AbstractAlong the south‐western coast of South America, three genera of fossil phocids (true seals) have been formally described from the late Neogene:AcrophocaandPiscophocafrom Chile and Peru, and, more recently,Hadrokirusfrom Peru, which all represent medium‐ to large‐sized phocids. Here, we report the discovery ofAustralophoca changorumgen. et sp. nov., a diminutive phocid from the late Miocene of the Bahía Inglesa Formation (northern Chile) and Pisco Formation (southern Peru), comparable in size with the smallest species of modern phocids. This taxon is based on diagnostic postcranial material, including a humerus that has an elongated deltopectoral crest but lacks an entepicondylar foramen; a femur with a subtrochanteric fossa, among other characters; in combination with a relatively small body size. All these features together distinguishA. changorumfrom all other reported pinnipeds. This new taxon not only increases the taxonomic and morphological diversity of phocids of the late Neogene of the eastern South Pacific Ocean, but it also provides new insights about the evolutionary history of fossil pinniped assemblages in South America and, broadly, in the southern hemisphere.

Analysis of seasonality in trophic relationships of true seals (Phocideae) in the White Sea

The analysis of interspecific trophic relations of true seals in the White Sea on the basis of long-term study, done on feeding, is shown. Main finding is that the ringed and bearded seals have no competitive interrelations. Contrastingly, the harp seal had an impact on background seals, intensity of the competition was, however, insignificant due of harp seal seasonal stay in the White Sea. The ice-free seals, i.e. grey and harbor seals, did not show a trophic competition with ice-liking seals thanks to seasonality of stay in the White Sea and insignificant number. The trophic competition of these seals to other pinnipeds is possible at restoration of areas.