Lobodon carcinophaga

Adam, Peter

doi:10.1644/1545-1410(2005)772[0001:lc]2.0.co;2

Cited by 20 publications

(13 citation statements)

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“…This phenomenon leads to significant amounts of body heat loss through the surfaces of the palate and tongue (Heyning and Mead, ; Ford et al, ). The teeth of toothed mysticetes are multicuspate and superficially resemble those of two pinnipeds that are known to filter feed – Lobodon carcinophagus (crabeater seal; Adam and Berta, ; Adam, ) and Hydrurga leptonyx (leopard seal; Hocking et al, ). Given the connection between multicuspate teeth and filter feeding in extant pinnipeds, bulk filter feeding has been hypothesized for some toothed mysticetes, including the earliest diverging mammalodontids (Fordyce, ; Mitchell, ; Barnes et al, ; Fordyce and Barnes, ; Ichishima, ).…”

Section: Discussionmentioning

confidence: 99%

Vascularization of the Gray Whale Palate (Cetacea, Mysticeti, Eschrichtius robustus): Soft Tissue Evidence for an Alveolar Source of Blood to Baleen

Ekdale

Deméré

Berta

2015

The Anatomical Record

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The origin of baleen in mysticetes heralded a major transition during cetacean evolution. Extant mysticetes are edentulous in adulthood, but rudimentary teeth develop in utero within open maxillary and mandibular alveolar grooves. The teeth are resorbed prenatally and the alveolar grooves close as baleen germ develops. Arteries supplying blood to highly vascularized epithelial tissue from which baleen develops pass through lateral nutrient foramina in the area of the embryonic alveolar grooves and rudimentary teeth. Those vessels are hypothesized to be branches of the superior alveolar artery, but branches of the greater palatine arteries may play a role in the baleen vascularization. Through a combination of latex injection, CT, and traditional dissection of the palate of a neonatal gray whale (Eschrichtius robustus), we confirm that the baleen receives blood from vessels within the superior alveolar canal via the lateral foramina. The greater palatine artery is restricted to its own passage with no connections to the baleen. This study has implications for the presence of baleen in extinct taxa by identifying the vessels and bony canals that supply blood to the epithelium from which baleen develops. The results indicate that the lateral foramina in edentulous mysticete fossils are bony correlates for the presence of baleen, and the results can be used to help identify bony canals and foramina that have been used to reconstruct baleen in extinct mysticetes that retained teeth in adulthood. Further comparisons are made with mammals that also possess oral keratin structures, including ruminants, ornithorhynchid monotremes, and sirenians. Anat Rec, 298:691-702, 2015. V C 2015 Wiley Periodicals, Inc.Key words: baleen; gray whale; Eschrichtius robustus; vascularization; palateIn this article, we investigate the blood supply to the baleen and surrounding epithelium covering the hard palate in a neonatal gray whale (Eschrichtius robustus). Baleen is a neomorphic keratinous structure that is unique to mysticete cetaceans (baleen whales) and functions as a natural sieve to trap prey during filter feeding (Pivorunas, 1979;Werth, 2001Werth, , 2004Werth, , 2013. Baleen develops as a series of transverse laminae (main and minor plates) that form a pair of bilateral racks along the ventrolateral borders of the maxillae. The racks of baleen laminae (or baleen racks) are oriented parasagittally, and they are deeply embedded within the highly Additional Supporting Information may be found in the online version of this article.

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Section: Discussionmentioning

confidence: 99%

Vascularization of the Gray Whale Palate (Cetacea, Mysticeti, Eschrichtius robustus): Soft Tissue Evidence for an Alveolar Source of Blood to Baleen

Ekdale

Deméré

Berta

2015

The Anatomical Record

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“…Moreover, the 14 C activity will vary regionally and as the result of the lifestyle of a particular animal. Although the specific area where the collected specimens of crabeater seal feed is unknown, crabeater seals are year-round residents of the Antarctic pack ice, feeding mainly on Antarctic krill (Laws 1985;Lowry et al 1988;Adam 2005), and never travel in open water for more than a few days (Nordøy et al 1995). This suggests that the mummified specimens were feeding mostly on krill and in an area near the place where they were found.…”

Section: Discussionmentioning

confidence: 99%

“…Of the 6 species of Antarctic pinnipeds, 4 of them, known as pack-ice seals (APIS 1995), inhabit the pack-ice region: crabeater seals (Lobodon carcinophaga), leopard seals (Hydrurga leptonyx), Weddell seals (Leptonychotes weddelli), and Ross seals (Ommatophoca rossii). Crabeater seals are by far the most abundant, comprising 80-95% of all the seals observed on the pack ice (Laws 1984;Adam 2005). These seals are krill-feeding specialists (Lowry et al 1988;Nordøy et al 1995;Adam 2005).…”

Section: Introductionmentioning

confidence: 99%

“…Crabeater seals are by far the most abundant, comprising 80-95% of all the seals observed on the pack ice (Laws 1984;Adam 2005). These seals are krill-feeding specialists (Lowry et al 1988;Nordøy et al 1995;Adam 2005). Although L. carcinophaga are widely dispersed on the heavy pack ice, little is known about their distribution and behavior, especially during winter (Lowry et al 1988;Nordøy et al 1995).…”

Section: Introductionmentioning

confidence: 99%

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Antarctic Radiocarbon Reservoir: The Case of the Mummified Crabeater Seals (Lobodon Carcinophaga) in Bodman Cape, Seymour Island, Antarctica

et al. 2011

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ABSTRACT. At least 50% of the world's seal population is distributed in the pack-ice region surrounding Antarctica. Among the Antarctic seals, Lobodon carcinophaga (commonly known as "crabeater seals") are the most abundant. This is a krill-feeding species, subsisting primarily on Euphausia superba. The occurrence of mummified seals has been documented since 1900 in several Antarctic regions, and different hypotheses about age and what happened to them have been proposed. Taking into account the depletion of 14 C concentration in marine waters, we dated a recently deceased and a mummified L. carcinophaga along with a mollusk (Nacella concinna) collected alive from different locations around Antarctica. We discuss their relationship in light of the 14 C reservoir. The age obtained for the recently deceased crabeater seals suggests a reservoir age of around 1300 yr for these waters, which is in agreement with the correction value for reservoir age obtained for the same species in the area. We applied this reservoir correction value to the conventional age of 1180 14 C yr BP obtained for the mummified seal. The results indicate that the death event probably occurred within the last 100 yr. The age obtained for the mollusk specimen confirms that the correction values of the reservoir effect for the Antarctic continent vary according to geographical location and to the type of sample dated.

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“…For example, crabeater seals, Lobodon carcinophaga, and minke whales, Balaenoptera acutorostrata, living closer to the Antarctic continent, feed almost exclusively (>95 % by mass) on krill (Armstrong and Siegfried 1991;Adam 2005). At Bird Island, South Georgia, the mean percentage of krill consumed by mass by Macaroni penguins Eudyptes chrysolophus between 1977 and 1995 was 89.8 %, with years higher than 90 % (Croxall et al 1999).…”

Section: Box 121: Top Predators and Antarctic Krillmentioning

confidence: 99%

Life Beyond the Ice

Xavier

Peck

2015

Exploring the Last Continent

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The Antarctic Circumpolar Current isolates Antarctic waters and their living organisms from warmer waters to the north. Over the last 25-35 million years, this isolation has led to specific environmental conditions, including a sharp drop in water temperatures south of the Polar Frontal Zone and the formation of sea ice during winter. Three key factors control productivity in the Southern Ocean today. Firstly, the Southern Ocean contains about 1.8 times as much oxygen as tropical seawater because more oxygen can dissolve in water at lower temperatures. Secondly, upwelling currents bring nutrients from the seabed to feed microscopic algae at the surface, and, lastly, the seasonal formation of sea ice has a profound impact on marine life. In addition, there is a long period of low or no light in winter, extreme physical disturbance from icebergs and a very high level of coastal productivity. All these factors have been important in the evolution of the characteristic Southern Ocean species and have resulted in a high degree of endemism, particularly in certain groupings of Antarctic organisms such as crustaceans and fish. The Southern Ocean represents 9.6 % of the world's oceans and is a key part of Earth's system. As the climate changes and sea level rises, the behavior of deepocean currents associated with the global thermohaline conveyor belt is altered and marine organisms respond. Our knowledge of the Southern Ocean has increased considerably in the last 20 years, but our understanding of adaptations, biological cycles and responses to change is still poor and more research is needed.

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Lobodon carcinophaga

Cited by 20 publications

References 91 publications

Vascularization of the Gray Whale Palate (Cetacea, Mysticeti, Eschrichtius robustus): Soft Tissue Evidence for an Alveolar Source of Blood to Baleen

Vascularization of the Gray Whale Palate (Cetacea, Mysticeti, Eschrichtius robustus): Soft Tissue Evidence for an Alveolar Source of Blood to Baleen

Antarctic Radiocarbon Reservoir: The Case of the Mummified Crabeater Seals (Lobodon Carcinophaga) in Bodman Cape, Seymour Island, Antarctica

Life Beyond the Ice

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