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Kaewmong P, Jongjit P, Boonkasemsanti A, Kittiwattanawong K, Kongtueng P, Matchimakul P, Tangphokhanon W, Pirintr P, Khonmee J, Buddhasiri S, Piboon P, Umsumarng S, Mektrirat R, Nganvongpanit K, Pongkan W. Histological study of seventeen organs from dugong ( Dugong dugon). PeerJ 2023; 11:e15859. [PMID: 37663296 PMCID: PMC10473042 DOI: 10.7717/peerj.15859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 07/17/2023] [Indexed: 09/05/2023] Open
Abstract
Background Dugongs are marine mammals with a crescent-shaped tail fluke and a concave trailing margin that belong to the family Dugongidae., They are distributed widely in the warm coastal waters of the Indo-Pacific region. Importantly, the population of dugongs has decreased over the past decades as they have been classified as rare marine mammals. Previous studies have investigated the habitat and genetic diversity of dugongs. However, a comprehensive histological investigation of their tissue has not yet been conducted. This study provides unique insight into the organs of dugongs and compares them with other mammal species. Methods Tissue sections were stained with Harris's hematoxylin and eosin Y. The histological structure of 17 organ tissues obtained from eight systems was included in this study. Tissue sections were obtained from the urinary system (kidney), muscular system (striated skeletal muscle and smooth muscle), cardiovascular system (cardiac muscle (ventricle), coronary artery, and coronary vein), respiratory system (trachea and lung), gastrointestinal system (esophagus, stomach, small intestine, liver, and pancreas), reproductive system (testis), lymphatic system (spleen and thymus), and endocrine system (pancreas). Results While most structures were similar to those of other mammal species, there were some differences in the tissue sections of dugongs when compared with other mammalian species and manatees. These include the kidneys of dugongs, which were non-lobular and had a smooth, elongated exterior resulting in a long medullary crest, whereas the dugong pyloric epithelium did not have overlying stratified squamous cells and was noticably different from the Florida manatee. Discussion Histological information obtained from various organs of the dugong can serve as an essential foundation of basal data for future microanatomical studies. This information can also be used as high-value data in the diagnosis and pathogenesis of sick dugongs or those with an unknown cause of death.
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Affiliation(s)
| | | | | | | | - Piyamat Kongtueng
- Central Laboratory, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
- Research Center for Veterinary Biosciences and Veterinary Public Health, Chiang Mai University, Chiang Mai, Thailand
| | - Pitchaya Matchimakul
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wasan Tangphokhanon
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Prapawadee Pirintr
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Jaruwan Khonmee
- Research Center for Veterinary Biosciences and Veterinary Public Health, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Songphon Buddhasiri
- Research Center for Veterinary Biosciences and Veterinary Public Health, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Promporn Piboon
- Research Center for Veterinary Biosciences and Veterinary Public Health, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Sonthaya Umsumarng
- Research Center for Veterinary Biosciences and Veterinary Public Health, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Raktham Mektrirat
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Korakot Nganvongpanit
- Research Center for Veterinary Biosciences and Veterinary Public Health, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wanpitak Pongkan
- Research Center for Veterinary Biosciences and Veterinary Public Health, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
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The Respiratory System of the Arctocephalus australis in Comparison to the Dog as a Land-Carnivore: Are There Adaptations to Marine Life? Animals (Basel) 2023; 13:ani13020199. [PMID: 36670739 PMCID: PMC9855070 DOI: 10.3390/ani13020199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 01/07/2023] Open
Abstract
Marine mammals are divided into three groups, with similar adaptations resulting from their aquatic lifestyle: sirenians, pinnipeds, and cetaceans. The present work focused on the South American fur seal, or Arctocephalus australis, a carnivore included in the pinnipeds group. We assessed whether the anatomical features of the Arctocephalus australis' respiratory system are comparable to those of other land-carnivores or whether these individuals show anatomical adaptations related to their ability to dive or their breath-holding capacities. We studied 11 cadavers of Arctocephalus australis, which included adult (n = 2) and juvenile (n = 9) individuals, by anatomically dissecting their isolated entire respiratory system. Although it is generally similar to that in land-carnivores, we demonstrated that the Arctocephalus australis's respiratory apparatus shows several specific characteristics. Therefore, our results are of great importance for clinical diagnostic and wildlife conservation purposes.
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Martín-Orti R, Tostado-Marcos C, Loureiro JP, Molpeceres-Diego I, Tendillo-Domínguez E, Santos-Álvarez I, Pérez-Lloret P, González-Soriano J. The Digestive System of the Arctocephalus australis in Comparison to the Dog as a Land-Carnivore Model. Animals (Basel) 2022; 12:ani12131634. [PMID: 35804533 PMCID: PMC9264872 DOI: 10.3390/ani12131634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Marine mammals are warm-blooded vertebrates that behave in the same way as land mammals do but they spend most or all of their lives in the ocean. There is much previous research on whales, dolphins, or even different types of seals, including their behavior, health, anatomy or perception. Between all these fields, it is commonly accepted that anatomy is considered critical to understanding many physiological adaptations. For example, their ability to dive by holding their breath underwater for long periods of time. During this process they can postpone digestion for several hours. However, and contrary to what might be expected, our results show that being a carnivore seems to be the critical characteristic defining their digestive apparatus, the adaptations to the aquatic environment being less significant. Abstract Marine mammals play a critical ecological role as both predator and prey. They are divided into three groups that share similar adaptations to their aquatic life, but that have very different origins and life patterns: sirenians, pinnipeds, cetaceans. The species object of our interest is the South American fur seal or Arctocephalus australis, a carnivore classified within the group of pinnipeds. The objective of the present study was to evaluate whether the anatomical characteristics of the Arctocephalus australis’ digestive system are similar to that of other land-carnivores or if, on the contrary, this species shows anatomical adaptations related to their life in the ocean. The study was carried out on 11 cadavers of the species Arctocephalus australis, made up of two adults and nine juveniles, by means of the anatomical dissection of their entire isolated digestive system. We demonstrate that, with several exceptions, the anatomical characteristics of the digestive system of the Arctocephalus australis are similar to those in other carnivores. Therefore, our data constitute an important contribution for clinical diagnostic and conservation purposes, for both veterinarians and biologists.
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Affiliation(s)
- Rosario Martín-Orti
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
| | - Carlos Tostado-Marcos
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Juan-Pablo Loureiro
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Ignacio Molpeceres-Diego
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Enrique Tendillo-Domínguez
- Fundación Mundo Marino. Av. X 157, San Clemente del Tuyú B7105, Provincia de Buenos Aires, Argentina; (C.T.-M.); (J.-P.L.); (I.M.-D.); (E.T.-D.)
| | - Inmaculada Santos-Álvarez
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
| | - Pilar Pérez-Lloret
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
| | - Juncal González-Soriano
- Departamento de Anatomía y Embriología, Sección Departamental de Anatomía y Embriología (Veterinaria), Facultad de Veterinaria, Universidad Complutense, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain; (R.M.-O.); (I.S.-Á.); (P.P.-L.)
- Correspondence:
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Nourbakhsh H, Adams A, Raverty S, Vogl AW, Haulena M, Skoretz SA. Microscopic Anatomy of the Upper Aerodigestive Tract in Harbour Seals (Phoca vitulina): Functional Adaptations to Swallowing. Anat Rec (Hoboken) 2022; 306:947-959. [PMID: 35719006 DOI: 10.1002/ar.25025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/05/2022] [Accepted: 05/31/2022] [Indexed: 11/07/2022]
Abstract
Abandoned harbour seal pups (Phoca vitulina) are frequently recovered by rehabilitation centres and often require intensive nursing, gavage feeding and swallowing rehabilitation prior to anticipated release. Seal upper aerodigestive tract (UAT) histology descriptions relevant to deglutition are limited, impacting advances in rehabilitation practice. Therefore, we examined the histological characteristics of the harbour seal UAT to understand species-specific functional anatomy and characterize adaptations. To this end, we conducted gross dissections, compiled measurements and reviewed histologic features of the UAT structures of 14 pre-weaned harbour seal pups that died due to natural causes or were humanely euthanized. Representative samples for histologic evaluation included the tongue, salivary glands, epiglottis, and varying levels of the trachea and esophagus. Histologically, there was a prominent muscularis in the tongue with fewer lingual papillae types compared to humans. Abundant submucosal glands were observed in lateral and pharyngeal parts of the tongue and rostral parts of the esophagus. When compared to other mammalian species, there was a disproportionate increase in the amount of striated muscle throughout the length of the esophageal muscularis externa. This may indicate a lesser degree of autonomic control over the esophageal phase of swallowing in harbour seals. Our study represents the first detailed UAT histological descriptions for neonatal harbour seals. Collectively, these findings support specific anatomic and biomechanic adaptations relevant to suckling, prehension and deglutition. This work will inform rehabilitation practices and guide future studies on swallowing physiology in harbour seals with potential applications to other pinniped and otariid species in rehabilitation settings. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Hirad Nourbakhsh
- School of Audiology & Speech Sciences, University of British Columbia, Vancouver, BC
| | - Arlo Adams
- Life Sciences Institute & Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC
| | - Stephen Raverty
- Animal Health Center, 1767 Angus Campbell Road, Abbotsford, BC
| | - A Wayne Vogl
- Life Sciences Institute & Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC
| | - Martin Haulena
- Vancouver Aquarium Marine Mammal Rescue Centre, Vancouver, BC
| | - Stacey A Skoretz
- School of Audiology & Speech Sciences, University of British Columbia, Vancouver, BC.,Department of Critical Care Medicine, University of Alberta, Edmonton, AB
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CARDIAC EXAMINATIONS OF ANESTHETIZED STELLER SEA LIONS ( EUMETOPIAS JUBATUS), NORTHERN FUR SEALS ( CALLORHINUS URSINUS), AND A WALRUS ( ODOBENUS ROSMARUS). J Zoo Wildl Med 2021; 52:507-519. [PMID: 34130393 DOI: 10.1638/2020-0054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2020] [Indexed: 11/21/2022] Open
Abstract
Pinniped hearts have been well described via dissection, but in vivo measurements of cardiac structure, function, and electrophysiology are lacking. Electrocardiograms (ECGs) were recorded under anesthesia from eight Steller sea lions (Eumetopias jubatus), five northern fur seals (Callorhinus ursinus), and one walrus (Odobenus rosmarus) to investigate cardiac electrophysiology in pinnipeds. In addition, echocardiograms were performed on all eight anesthetized Steller sea lions to evaluate in vivo cardiac structure and function. Measured and calculated ECG parameters included P-wave, PQ, QRS, and QT interval durations, P-, R-, and T-wave amplitudes, P- and T-wave polarities, and the mean electrical axis (MEA). Measured and calculated echocardiographic parameters included left ventricular internal diameter, interventricular septum thickness, and left ventricular posterior wall thickness in systole and diastole (using M-mode), left atrium and aortic root dimensions (using 2D), and maximum aortic and pulmonary flow velocities (using pulsed-wave spectral Doppler). ECG measurements were similar to those reported for other pinniped species, but there was considerable variation in the MEAs of Steller sea lions and northern fur seals. Echocardiographic measurements were similar to those reported for southern sea lions (Otaria flavenscens), including five out of eight Steller sea lions having a left atrial to aortic root ratio <1, which may indicate that they have an enlarged aortic root compared to awake terrestrial mammals. Isoflurane anesthesia likely affected some of the measurements as evidenced by the reduced fractional shortening found in Steller sea lions compared to awake terrestrial mammals. The values reported are useful reference points for assessing cardiac health in pinnipeds under human care.
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Hanadhita D, Rahma A, Prawira AY, Mayasari NLPI, Satyaningtijas AS, Hondo E, Agungpriyono S. The spleen morphophysiology of fruit bats. Anat Histol Embryol 2019; 48:315-324. [PMID: 30968443 PMCID: PMC7159459 DOI: 10.1111/ahe.12442] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/12/2019] [Accepted: 03/16/2019] [Indexed: 11/29/2022]
Abstract
Spleen is one of the important lymphoid organs with wide variations of morphological and physiological functions according to species. Morphology and function of the spleen in bats, which are hosts to several viral strains without exhibiting clinical symptoms, remain to be fully elucidated. This study aims to examine the spleen morphology of fruit bats associated with their physiological functions. Spleen histological observations were performed in three fruit bats species: Cynopterus titthaecheilus (n = 9), Rousettus leschenaultii (n = 3) and Pteropus vampyrus (n = 3). The spleens of these fruit bats were surrounded by a thin capsule. Red pulp consisted of splenic cord and wide vascular space filled with blood. Ellipsoids in all three studied species were found numerously and adjacent to one another forming macrophages aggregates. White pulp consisted of periarteriolar lymphoid sheaths (PALS), lymphoid follicles and marginal zone. The lymphoid follicle contained a germinal centre and a tingible body macrophage that might reflect an active immune system. The marginal zone was prominent and well developed. This study reports some differences in spleen structure of fruit bats compared to other bat species previously reported and discusses possible physiological implications of the spleen based on its morphology.
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Affiliation(s)
- Desrayni Hanadhita
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Anisa Rahma
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Andhika Yudha Prawira
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Ni Luh Putu Ika Mayasari
- Department of Animal Disease and Veterinary Public Health, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Aryani Sismin Satyaningtijas
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Eiichi Hondo
- Laboratory of Animal Morphology, Graduate School of Bioagricultural SciencesNagoya UniversityNagoyaJapan
| | - Srihadi Agungpriyono
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
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Colegrove KM, Burek-Huntington KA, Roe W, Siebert U. Pinnipediae. PATHOLOGY OF WILDLIFE AND ZOO ANIMALS 2018. [PMCID: PMC7150363 DOI: 10.1016/b978-0-12-805306-5.00023-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This chapter reviews common diseases of pinnipeds, including species in the Otariidae (fur seals and sea lions), Phocidae (true seals), and Odobenidae (walrus) families. Much of the knowledge on pathologic conditions of pinnipeds comes from necropsies of stranded animals and those housed in captivity. As such, disease knowledge is biased toward species frequently housed in zoos and aquaria, those that strand more commonly, or those in which free-ranging populations are more easily accessible. Though historically systematic evaluations of wild populations have rarely been accomplished, in the past 10 years, with advances in marine mammal medicine and anesthesia, biologists and veterinarians more frequently completed live animal health field investigations to evaluate health and disease in free-ranging pinniped populations.
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Smodlaka H, Henry RW. Gross Anatomy of the Ringed Seal (Pusa hispida) Gastro-Intestinal Tract. Anat Histol Embryol 2013; 43:230-8. [DOI: 10.1111/ahe.12066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 04/21/2013] [Indexed: 11/30/2022]
Affiliation(s)
- H. Smodlaka
- The Western University of Health Sciences; College of Veterinary Medicine; 309 E. Second Street Pomona CA 91766-1854 USA
| | - R. W. Henry
- Department of Biomedical Sciences; College of Veterinary Medicine; University of Tennessee; 2407 River Drive Knoxville TN 37996 USA
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Freezing and thawing of pinniped carcasses results in artefacts that resemble traumatic lesions. Vet J 2012; 194:326-31. [DOI: 10.1016/j.tvjl.2012.03.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 03/22/2012] [Accepted: 03/29/2012] [Indexed: 11/24/2022]
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Ahrens L, Siebert U, Ebinghaus R. Total body burden and tissue distribution of polyfluorinated compounds in harbor seals (Phoca vitulina) from the German Bight. MARINE POLLUTION BULLETIN 2009; 58:520-525. [PMID: 19121527 DOI: 10.1016/j.marpolbul.2008.11.030] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/12/2008] [Accepted: 11/21/2008] [Indexed: 05/27/2023]
Abstract
Total body burden and tissue distribution of polyfluorinated compounds (PFCs) were investigated in harbor seals (Phoca vitulina) from the German Bight in 2007. A total number of 18 individual PFCs from the following groups could be quantified in the different tissues: perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs) and their precursors perfluorinated sulfinates (PFSiAs), perfluorinated sulfonamides, and sulfonamido ethanols. Perfluorooctanesulfonate (PFOS) was the predominant compound in all measured seal tissues (up to 1665 ng g(-1) wet weight in liver tissue). The dominant PFCAs were perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), but their concentrations were much lower compared to PFOS. The mean whole body burden in harbor seals of all detected PFCs was estimated to be 2665+/-1207 microg absolute. The major amount of the total PFCs burden in the bodies was in blood (38%) and liver (36%), followed by muscle (13%), lung (8%), kidney (2%), blubber (2%), heart (1%), brain (1%), thymus (<0.01%) and thyroid (<0.01%). These data suggest large differences in body burden and accumulation pattern of PFCs in marine mammals.
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Affiliation(s)
- Lutz Ahrens
- GKSS Research Centre Geesthacht, Department for Environmental Chemistry, Institute for Coastal Research, Max-Planck-Str. 1, DE-21502 Geesthacht, Germany.
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Pérez W, Katz H, Lima M. Gross heart anatomy of Arctocephalus australis (Zimmerman, 1783). Anat Sci Int 2008; 83:6-10. [DOI: 10.1111/j.1447-073x.2007.00189.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Smodlaka H, Henry RW, Schumacher J, Reed RB. Macroscopic Anatomy of the Heart of the Ringed Seal (Phoca hispida). Anat Histol Embryol 2007; 37:30-5. [DOI: 10.1111/j.1439-0264.2007.00791.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gray R, Canfield P, Rogers T. Histology of selected tissues of the leopard seal and implications for functional adaptations to an aquatic lifestyle. J Anat 2007; 209:179-99. [PMID: 16879598 PMCID: PMC2100313 DOI: 10.1111/j.1469-7580.2006.00591.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The microscopic anatomy of the cardio-respiratory system, digestive system, kidney, lymphatic system and integument was investigated in the leopard seal, Hydrurga leptonyx, by examining histological sections of tissues collected from leopard seals in Antarctica and New South Wales, Australia. The majority of the tissues had similar histological features to those described in terrestrial mammals and other pinniped species, particularly phocid seals. Differences noted included readily identifiable Purkinje cells within the endocardium, muscular rather than cartilaginous reinforcement of the smaller airways, a single capillary layer within the alveolar septa, limited and variable keratinization of the oesophageal epithelium, few lymphoid follicles within the lamina propria of the gastrointestinal tract, and an absence of a sporta perimedullaris musculosa described in the kidney of cetaceans and some pinniped species. Adaptations of the lung, spleen and integument, similar to those described in other pinnipeds, including reinforcement of the pulmonary terminal airways, prominent pulmonary interlobular septa, ample smooth muscle in the capsule and trabeculae of the spleen, increased thickness of the epidermis, well-developed dermal sebaceous glands, and a thick blubber layer, appear to confer upon the leopard seal advantages related to its aquatic lifestyle.
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Affiliation(s)
- Rachael Gray
- Faculty of Veterinary Science, University of Sydney, NSW 2006, Australia.
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Drabek CM, Burns JM. Heart and aorta morphology of the deep-diving hooded seal (Cystophora cristata). CAN J ZOOL 2002. [DOI: 10.1139/z02-181] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An investigation of the heart morphology of 8 male and 15 female hooded seals (Cystophora cristata) revealed that the heart is proportionately large and the aortic bulb is larger than that reported for most seals. Hooded seals of all ages have large hearts (0.64% of the body mass) and the right ventricle is proportionately longer and more muscular than reported for other seals. The bulb of the ascending aorta shows the large-diameter characteristic of seals capable of making long deep dives, and is constricted to a diameter of less than one-third in the descending aorta. In addition, the ascending aorta has a much greater concentration of elastin fibers than does the descending aorta. In combination with the large right ventricle, these features probably serve to increase lung perfusion during the hooded seal's surface recovery, and to maintain a high blood pressure throughout the cardiac cycle during diving bradycardia. That there was no substantive difference in the heart morphology of pups, yearlings, and adults, suggests that these features are important in the development of diving behavior, and agrees with the rapid behavioral and physiological development of hooded seal neonates.
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