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Marmontel, Miriam; Odell, Daniel Keith; Reynolds, John E., III
(detail)
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1992 |
Reproductive biology of South American manatees. In: W. C. Hamlett (ed.), Reproductive biology of South American vertebrates.
New York, Springer-Verlag (1-328): 295-312. 1 tab. 9 figs.
–Reviews available data on sir. reproductive anatomy, physiology, and behavior and their implications for conservation, emphasizing T. manatus and T. inunguis.
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Hernandez, Patricia; Reynolds, John E., III; Marsh, Helene D.; Marmontel, Miriam
(detail)
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1995 |
Age and seasonality in spermatogenesis of Florida manatees. In: T. J. O'Shea, B. B. Ackerman, & H. F. Percival (eds.), Population biology of the Florida manatee (q.v.).
Information & Technology Rept. (U.S. Dept. Interior, Natl. Biological Service) (vi + 289) 1: 84-97. 3 tabs. 10 figs. 1 app. Aug. 1995.
–Abstr. in O'Shea et al. (1992: 17).
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Marmontel, Miriam
(detail)
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1995 |
Age and reproduction in female Florida manatees. In: T. J. O'Shea, B. B. Ackerman, & H. F. Percival (eds.), Population biology of the Florida manatee (q.v.).
Information & Technology Rept. (U.S. Dept. Interior, Natl. Biological Service) (vi + 289) 1: 98-119. 13 tabs. 9 figs. Aug. 1995.
–Abstr. in O'Shea et al. (1992: 16).
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Marmontel, Miriam; O'Shea, Thomas J.; Kochman, Howard I.; Humphrey, Stephen R.
(detail)
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1996 |
Age determination in manatees using growth-layer-group counts in bone.
Mar. Mamm. Sci. 12(1): 54-88. 3 tabs. 17 figs. Jan. 2, 1996.
–Describes growth-layer groups in an enlarged sample of T. m. latirostris and T. m. manatus, showing that maximum layer counts are obtained from the middle third of the dome region (= pars temporalis or tegmen tympani) of the periotic bone, and that data from known-age, known minimum-age, and tetracycline-marked animals are consistent with annual deposition of the layers. Bone resorption does not affect accuracy of layer counts until ages greater than about 15 years and body lengths greater than 300 cm are attained. Use of layer counts from the periotic bone is considered suitable for studies of population dynamics and other age-related aspects of manatee biology.
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Marmontel, Miriam; Humphrey, Stephen R.; O'Shea, Thomas J.
(detail)
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1997 |
Population viability analysis of the Florida manatee (Trichechus manatus latirostris).
Conserv. Biol. 11(2): 467-481. 3 tabs. 5 figs. Apr. 1997.
–Spanish summ. Computer modeling, based on data fron 1,212 salvaged carcasses, projects an unacceptably low probability of population persistence over 1,000 years. A 10% increase in adult mortality, or a 10% decrease in reproduction, would cause extinction within that period, whereas a 10% decrease in adult mortality would allow slow population growth. Increasing numbers of people and boats portend an increase in manatee mortality; therefore, without effective regulation of boating, the Florida manatee is likely to decline slowly to extinction.
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Garcia-Rodriguez, Angela I.; Bowen, B. W.; Domning, Daryl Paul; Mignucci Giannoni, Antonio A.; Marmontel, Miriam; Montoya Ospina, Ruby A.; Morales-Vela, Benjamín; Rudin, M.; Bonde, Robert K.; McGuire, Peter M.
(detail)
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1998 |
Phylogeography of the West Indian manatee (Trichechus manatus): how many populations and how many taxa?
Molecular Ecology 7(9): 1137-1149. 6 tabs. 2 figs. + cover photo. Sept. 1998.
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Rosas, Fernando César Weber; Lehti, Kesä Kannikah; Marmontel, Miriam
(detail)
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1999 |
Hematological indices and mineral content of serum in captive and wild Amazonian manatees, Trichechus inunguis.
Arq. Bras. Ciên. Vet. Zool. UNIPAR 2(1): 37-42. 3 tabs. Jan./July 1999.
–Portuguese & Spanish summs. Captive male manatees were found to be very deficient in zinc, magnesium, iron, potassium, and calcium, and marginally deficient in copper. Captive females were marginally deficient in copper, magnesium, iron, potassium, and calcium. The greater degree of deficiency in the males may indicate a natural difference between the sexes.
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Vianna, Juliana A.; Bonde, Robert K.; Caballero, Susana; Giraldo, Juan Pablo; Pinto de Lima, Régis; Clark, Annmarie; Marmontel, Miriam; Morales-Vela, Benjamín; Souza, Maria José de; Parr, Leslee; Rodríguez-Lopez, Marta A.; Mignucci-Giannoni, Antonio A.; Powell, James Arthur, Jr.; Santos, Fabrício R.
(detail)
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2006 |
Phylogeography, phylogeny and hybridization in trichechid sirenians: implications for manatee conservation.
Molec. Ecol. 15(2): 433-447. 4 tabs. 4 figs.
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Borges, João Carlos Gomes; Alves, Leucio Câmara; Lima, Danielle dos Santos; Luna, Fábia de Oliveira; Aguilar, Carla Verônica Carrasco; Vergara-Parente, Jociery Einhardt; Faustino, Maria Aparecida da Glória; Lima, Ana Maria Alves; Marmontel, Miriam
(detail)
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2007a |
Ocurrencia de Cryptosporidium spp. en manatí amazônico (Trichechus inunguis, Natterer, 1883).
Biotemas 20(3): 63-66. Sept. 2007.
–Engl. summ.
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Calvimontes, Jorge; Marmontel, Miriam
(detail)
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2010 |
Estudios etnobiológicos sobre el manatí amazónico (Trichechus inunguis Natterer) y su conservación en la Reserva de Desarrollo Sostenible Amanã, Brasil. In: Á. Moreno Fuentes, M. T. Pulido Silva, R. Mariaca Méndez, R. Valadez Azúa, P. Mejía Correa, & T. V. Gutiérrez (eds.), Sistemas biocognitivos tradicionales: paradigmas en la conservación biológica y el fortalecimiento cultural.
Asociación Etnobiológica Méxicana, A.C. (with Global Diversity Foundation, El Colegio de la Frontera Sur, Universidad Autónoma del Estado de Hidalgo, & Sociedad Latinoamericana de Etnobiologia): 396-401.
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Vergara-Parente, Jociery Einhardt; Parente, Cristiano Leite; Marmontel, Miriam; Ramos Silva, Jean Carlos; Bezerra Sá, Fabrício
(detail)
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2010b |
Standard of measurement among local inhabitants in the middle Solimões, occidental Amazonia, and its use in morphometrics of Amazonian manatee (Trichechus inunguis Natterer, 1883).
Uakari 6(2): 37-43. Dec. 2010.
–Portuguese summ. Measurements of the hand span (tip of thumb to tip of little finger) of 22 Amazonian manatee hunters yielded a mean value of 21.71 cm for the "palmo", the usual unit of measurement they employ for curved-line body lengths of captured manatees. This value differs from some conversion values used in the literature. In the English text of this paper, "palmo" is consistently mistranslated as "inch" rather than "span".
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Borges, João Carlos Gomes; Alves, Leucio Câmara; Faustino, Maria Aparecida da Gloria; Marmontel, Miriam
(detail)
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2011 |
Occurrence of Cryptosporidium spp. in Antillean manatees (Trichechus manatus) and Amazonian manatees (Trichechus inunguis) from Brazil.
Journal of Zoo and Wildlife Medicine 42(4): 593-596. 1 table. DOI:10.1638/2010-0216.1. Dec. 2011.
–ABSTRACT: Infections by Cryptosporidium spp. in aquatic mammals is a major concern due to the possibility of the waterborne transmission of oocysts. The aim of the present study was to report the occurrence of Cryptosporidium spp. in Antillean manatees (Trichechus manatus) and Amazonian manatees (Trichechus inunguis) from Brazil. Fecal samples were collected and processed using Kinyoun's method. Positive samples were also submitted to the direct immunofluorescence test. The results revealed the presence of Cryptosporidium spp. oocysts in 12.5%% (17/136) of the material obtained from the Antillean manatees and in 4.3%% (05/115) of the samples from the Amazonian manatees. Cryptosporidium spp. infection was more prevalent in captive animals than in free-ranging specimens.
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Guterres-Pazin, Michelle Gil; Rosas, Fernando César Weber; Marmontel, Miriam
(detail)
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2012 |
Ingestion of invertebrates, seeds, and plastic by the Amazonian manatee (Trichechus inunguis) (Mammalia, Sirenia).
Aquatic Mammals 38(3): 322-324. DOI: 10.1578/AM.38.3.2012.322.
–ABSTRACT: The living Sirenia belong to the only group of herbivorous aquatic mammals which occur in river systems and coastal tropical and subtropical waters. From this group, the Amazonian manatee (Trichechus inunguis) is the smallest species, exclusively from fresh-water and endemic to the Amazon Basin. Sirenians are monogastric herbivores with post-gastric digestion and a low metabolic rate. Aquatic and semi-aquatic macrophytes are the main food source for Amazonian manatees, and the species composition and abundance of these plants are strongly influenced by the Amazonian hydrological pulse, which consequently influences the annual supply of food for the manatees. As accidental ingestion of microorganisms and seeds does not affect the health of the manatee even when not digested, the major concern is centered on the growing process of environmental degradation, mainly caused by indirect and direct deposition of waste in the rivers of the Amazon.
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Aragones, Lemnuel V.; Marmontel, Miriam; Kendall, Sarita
(detail)
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2012c |
Working with communities for sirenian conservation. Chap. 24 in: E. M. Hines et al. (eds.), Sirenian conservation: issues and strategies in developing countries (q.v.).
Gainesville, University Press of Florida (xiv + 326): 221-227.
–Includes box essay by Kanjana Adulyanukosol (p. 224, "Thailand").
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Arévvalo-Gonzalez, G. Katerin; Castelblanco-Martínez, Delma Nataly; Sánchez-Palomino, P.; López-Arévalo, H. F.; Marmontel, Miriam
(detail)
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2014 |
Complementary methods to estimate population size of Antillean manatees (Sirenia: Trichechidae) at Ciénaga de Paredes, Santander, Colombia.
Journal of Threatened Taxa 6(6): 5830-5837. 2 tabs. 3 figs. DOI:10.11609/JoTT.o3156.5830-7. June 26, 2014.
–ABSTRACT: Information on manatee population size in Colombia is limited. This study was aimed at determining manatee population size in the Cienaga de Paredes (Colombia) by three different methods: boat-based surveys, side-scan Sonar (SSS) surveys and local interviews. Manatees were counted during breathing events by direct observation during the dry season, with the number of sightings per hour (NSH) and maximum number of simultaneous sightings (MNSS) used as occurrence indices. In 2002, we obtained an average NSH of 27.62 (SD=12.34) and the MNSS was 18; in 2010 the values were 55.71 (SD=29.79) and four respectively. Using linear-transect SSS data we estimated a population size of 12 individuals (%CV=27.3). The local community claimed that no hunting or entanglements had taken place in the area for over 20 years. These methods have pros and cons in terms of investment, effort, efficiency and community involvement, and their efficiency may vary in different seasons. Applying them in a complementary way and at greater spatial and temporal scales could enhance the accuracy of results.
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Guterres-Pazin, Michelle Gil; Marmontel, Miriam; Rosas, Fernando César Weber; Pazin, Victor F. V.; Venticinque, Eduardo M.
(detail)
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2014 |
Feeding ecology of the Amazonian manatee (Trichechus inunguis) in the Mamirauá and Amanã Sustainable Development Reserves, Brazil.
Aquatic Mammals 40(2): 139-149. 3 tabs. 4 figs. doi:10.1578/AM.40.2.2014.139
–ABSTRACT: The Amazonian manatee (Trichechus inunguis) is an exclusively herbivorous freshwater mammal. Between 1994 and 2008, 230 fecal and 16 stomach content samples from wild Amazonian manatees were obtained. The material was collected during both dry and wet seasons in the sustainable development reserves of Mamirauá (MSDR) and Amanã (ASDR) from floodplain and terra firme and igapó (not subject to long-term flooding) habitats, respectively. Species constituting the diet of the Amazonian manatee were identified through a comparative analysis with a reference collection of epidermis from 69 plant species of potential consumption by the species. Forty-nine plant species were identified in the species' diet. In the MSDR, 32 plant species were found -- 18 during the dry season and 28 during the wet season. In the ASDR, 48 species were identified of which 40 occurred in both periods. A total of 30 new species were added to the Amazonian manatee diet known to date. The species that were found most frequently in the material were Hymenachne amplexicaulis, Oryza grandiglumis, Paspalum repens, Azolla caroliniana, and Limnobium spongia. Poaceae was the family with the greatest frequency of occurrence (91.5%). Plant species most consumed present emergent or floating habits. There was a difference in the composition of plant species found in manatee feces between the dry and wet seasons (p = 0.0002) but not between floodplain and igapó. Results show that the Amazonian manatee feeds on a great variety of plant species during the wet and dry season alike, and both in floodplain and igapó environments. Therefore, food availability alone does not represent a determining factor to explain the seasonal migration of the species.
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Barros, Helen M. D.do R.; Meirelles, Ana C. O.; Luna, Fábia O.; Marmontel, Miriam; Cordeiro-Estrela, Pedro; Santos, Neide; Astúa, Diego
(detail)
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2016 |
Cranial and chromosomal geographic variation in manatees (Mammalia: Sirenia: Trichechidae) with the description of the Antillean manatee karyotype in Brazil.
J. Zool. Syst. Evol. Res. 55(1): 73-87. doi: 10.1111/jzs.12153. Nov. 23, 2016.
–ABSTRACT: We employed landmark-based 3D geometric morphometrics to assess cranial size and shape diversification in Trichechus manatus and T. inunguis to compare it with patterns among all manatee taxa (T. manatus latirostris, T. m. manatus, T. inunguis and T. senegalensis), and to analyze geographic variation within American manatee populations, using a sample of 189 skulls. Chromosome G- and C-banding techniques were performed in T. m. manatus from Brazil. All taxa were statistically discriminated by skull shape. Trichechus m. manatus and T. m. latirostris have larger skulls than T. inunguis. A morphological discontinuity was noted within T. m. manatus, with the Brazilian population south of the Amazon discriminated from the T. m. manatus Caribbean and T. m. latirostris USA populations. Specimens from Suriname and Guyana had a skull shape more similar to the one from the Caribbean population. The Brazil Antillean manatee population exhibited morphological differences similar in magnitude to those found between the Amazonian and African species. Additionally, structural chromosome differences were detected between that population (chromosome pair 4 is metacentric and 10 is submetacentric) and manatees from Puerto Rico and Florida. Based on such morphological discontinuity and chromosomal divergence, we hypothesize that the Amazon River mouth may be acting as a reproductive barrier for the T. m. manatus population in Brazil, thus indicating that its taxonomic status and conservation strategies need an urgent reassessment.
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Guerra Neto, Guilherme; Galvão Bueno, Marina; Silveira Silva, Rodrigo Otavio; Faria Lobato, Francisco Carlos; Plácido Guimarães, Juliana; Bossart, Gregory D.; Marmontel, Miriam
(detail)
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2016 |
Acute necrotizing colitis with pneumatosis intestinalis in an Amazonian manatee calf.
Diseases of Aquatic Organisms 120: 189-194. 2 figs. doi: 10.3354/dao03019. Aug. 9, 2016.
–ABSTRACT: On 25 January 2014, a 1 mo old female Amazonian manatee Trichechus inunguis calf weighing 12 kg was rescued by air transport in Guajará, Brazil, and transferred to Mamirauá Institute's Community-based Amazonian Manatee Rehabilitation Center. The calf presented piercing/cutting lesions on the back, neck, and head, in addition to dehydration and intermittent involuntary buoyancy. X-ray analysis revealed a large amount of gases in the gastrointestinal tract. Daily procedures included wound cleaning and dressing, clinical and laboratory monitoring, treatment for intestinal tympanism, and artificial feeding. Adaptation to the nursing formula included 2 kinds of whole milk. Up to 20 d post-rescue the calf presented appetite, was active, and gained weight progressively. Past this period the calf started losing weight and presented constant involuntary buoyancy and died after 41 d in rehabilitation. The major findings at necropsy were pneumatosis intestinalis in cecum and colon, pulmonary edema, and hepatomegaly. The microscopic examination revealed pyogranulomatous and necrohemohrragic colitis with multinucleated giant cells, acute multifocal lymphadenitis with lymphoid depletion in cortical and paramedullary regions of mesenteric lymph nodes, and diffuse severe acinar atrophy of the pancreas. Anaerobic cultures of fragments of cecum and colon revealed colonies genotyped as Clostridium perfringens type A. We speculate that compromised immunity, thermoregulatory failure, and intolerance to artificial diet may have been contributing factors to the infection, leading to enterotoxemia and death.
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Arraut, Eduardo Moraes; Arraut, J. L.; Marmontel, Miriam; Mantovani, J. E.; Novo, E. M. L. M.
(detail)
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2017 |
Bottlenecks in the migration routes of Amazonian manatees and the threat of hydroelectric dams.
Acta Amazonica 47(1): 7-18. 4 tabs. 7 figs. DOI: 10.1590/1809-4392201600862. Jan./Mar. 2017.
–ABSTRACT: In a particular region within western Amazonia, Amazonian manatees (Trichechus inunguis) live in a floodplain environment that becomes inhospitable for them during the annual low-water season. To flee from it, they undergo a dangerous migration to a refuge while water levels are dropping fast. Our aim was to better understand the role of depth variation in this migratory process. We analyzed the sole tracking data on wild manatees (n=10 males), 30 years of Landsat images, a 14-year hydrograph and a 3-D bathymetric model. Migratory routes contained shallower segments, here called 'migratory bottlenecks', which dried out at the end of most lowering-water seasons, blocking the passage to the refuge. Manatees began migrating just in time to traverse the bottlenecks furthest away, suggesting they fine-tuned their departure so as to maximize time within the foraging home range without compromising safety. They apparently achieved this by estimating depth at the bottlenecks. Moreover, a bottleneck was created in >15 years, illustrating the environment's dynamism and the challenge this imposes upon manatees. Our results are probably generalizable to most of the species' range. We contend manatees possess an updatable cognitive map of their environment and are behaviorally plastic. Current dam-building plans, if implemented, would create more bottlenecks and make flooding less predictable, increasing manatee mortality from unsuccessful migrations. It would also partition the species into small populations, each prone to short-term extinction. The natural outcome would be the second species-level collapse. Economic growth should not come at the expense of the extinction of the iconic manatee.
RESUMO: Em uma região particular da Amazônia ocidental, peixes-boi amazônicos (Trichechus inunguis) vivem em um ambiente que se torna inóspito para eles durante a água-baixa anual. Para fugir dele, realizam uma migração perigosa para o refúgio enquanto o nível da água desce rapidamente. Nosso objetivo foi compreender melhor o papel da variação da profundidade neste processo migratório. Analisamos os únicos dados de rastreamento de peixes-boi selvagens (n=10 machos), 30 anos de imagens Landsat, 14 anos de hidrógrafa e um modelo batimétrico 3-D. As rotas migratórias possuíam trechos mais rasos, denominados gargalos migratórios, que secaram no final da maioria das vazantes, bloqueando o acesso ao refúgio. Os peixes-boi começaram a migração em tempo justo para atravessar os gargalos mais distantes, sugerindo que a sintonizaram para maximizar o período se alimentando sem comprometer a segurança. Para tal, parecem ter estimado a profundidade nos gargalos. Adicionalmente, um gargalo foi criado em <15 anos, ilustrando o dinamismo do ambiente e o desafio que isto impõe aos peixes-boi. Esses resultados provavelmente valem para boa parte da área de distribuição da espécie. Argumentamos que peixes-boi possuem um mapa cognitivo atualizável do ambiente e são comportamentalmente plásticos. Os planos de construção de barragens hidrelétricas, se concretizados, criariam mais gargalos e regimes de inundação menos previsíveis, dificultando a migração e consequentemente aumentando a mortalidade de peixes-boi. Também particionariam a espécie em populações pequenas, vulneráveis à extinção no curto-prazo. O desfecho seria o segundo colapso da espécie. O crescimento econômico não deve vir às custas da extinção do icônico peixe-boi.
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Marsh, Helene D.; Arraut, Eduardo Moraes; Keith Diagne, Lucy; Edwards, Holly H.; Marmontel, Miriam
(detail)
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2017 |
Impact of climate change and loss of habitat on sirenians. Chap. 19 in: Andy Butterworth (ed.), Marine mammal welfare: human induced change in the marine environment and its impacts on marine mammal welfare.
Springer International Publishing: Animal Welfare Series, Vol. 17: 333-357. DOI: https://doi.org/10.1007/978-3-319-46994-2. June 20, 2017.
–ABSTRACT: Although the impacts of climate change on the welfare of individual manatees and dugongs are still uncertain, the effects are likely to be through indirect interactions between meteorological and biotic factors and the human responses to climate change. We divided the potential impacts into (1) those that will potentially affect sirenians directly including temperature increases, sea-level rise, increased intensity of extreme weather events and changes in rainfall patterns and (2) indirect impacts that are likely to cause harm through habitat loss and change and the increase in the likelihood of harmful algal blooms and disease outbreaks. The habitat modification accompanying sea-level rise is likely to decrease the welfare of sirenians including increased mortality. Many species of tropical seagrasses live close to their thermal limits and will have to up-regulate their stress-response systems to tolerate the sublethal temperature increases caused by climate change. The capacity of seagrass species to evoke such responses is uncertain, as are the effects of elevated carbon dioxide on such acclimation responses. The increase in the intensity of extreme weather events associated with climate change is likely to decrease the welfare of sirenians through increased mortality from strandings, as well as habitat loss and change. These effects are likely to increase the exposure of sirenians to disease and their vulnerability to predators, including human hunters. Climate-related hazards will also exacerbate other stressors, especially for people living in poverty. Thus the risks to sirenians from climate change are likely to be greatest for small populations of dugongs and manatees occurring in low-income countries. The African manatee will be particularly vulnerable because of the high levels of human poverty throughout most of its range resulting in competition for resources, including protein from manatee meat.
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Lima, Camilla S.; Magalhães, Rafael F.; Marmontel, Miriam; Meirelles, Ana Carolina; Carvalho, Vitor Luz; Lavergne, Anne; Thoisy, Benoit de; Santos, Fabrício R.
(detail)
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2019 |
A hybrid swarm of manatees along the Guianas coastline, a peculiar environment under the influence of the Amazon River plume.
An. Acad. Bras. Ciênc. 91, supl. 3: e20190325. 3 figs. https://doi.org/10.1590/0001-3765201920190325 Aug. 26, 2019.
–ABSTRACT: The West Indian (Trichechus manatus) and Amazonian (T. inunguis) manatees have a sympatric occurrence at the mouth of the Amazon River. A result of this interspecific encounter is the occurrence of hybrids, which are frequently found along the coasts of Amapá state in Brazil, French Guiana and Guyana. Here we present new genetic evidence indicating the occurrence of a hybrid swarm along the Guianas Shield coastline, which is an interspecific hybrid zone that also separates T. manatus populations located east (Brazil) and west (Caribbean, Gulf of Mexico, Florida and Antilles). In addition, we suggest that this hybrid population occupies a peculiar mangrove-rich environment under strong influence of the Amazon River plume, which requires an independent management and should be considered a special conservation area.
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Souza, Érica Martinha Silva de; Freitas, Lucas; Ramos, Elisa Karen da Silva; Veiga, Giovanna Selleghin; Rachid-Ribeiro, Michelle Carneiro; Silva, Felipe André; Marmontel, Miriam; Santos, Fabrício Rodrigues dos; Laudisoit, Anne; Verheyen, Erik; Domning, Daryl Paul; Nery, Mariana Freitas
(detail)
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2021 |
The evolutionary history of manatees told by their mitogenomes.
Scientific Reports 11: 3564. 2 tabs. 5 figs. + online supplementary material. https://doi.org/10.1038/s41598-021-82390-2
–ABSTRACT: The manatee family encompasses three extant congeneric species: Trichechus senegalensis (African manatee), T. inunguis (Amazonian manatee), and T. manatus (West Indian manatee). The fossil record for manatees is scant, and few phylogenetic studies have focused on their evolutionary history. We use full mitogenomes of all extant manatee species to infer the divergence dates and biogeographical histories of these species and the effect of natural selection on their mitogenomes. The complete mitochondrial genomes of T. inunguis (16,851 bp), T. senegalensis (16,882 bp), and T. manatus(16,882 bp), comprise 13 protein-coding genes, 2 ribosomal RNA genes (rRNA - 12S and 16S), and 22 transfer RNA genes (tRNA), and (D-loop/CR). Our analyses show that the first split within Trichechus occurred during the Late Miocene (posterior mean 6.56 Ma and 95% HPD 3.81–10.66 Ma), followed by a iversifcation event in the Plio-Pleistocene (posterior mean 1.34 Ma, 95% HPD 0.1–4.23) in the clade composed by T. inunguis and T. manatus; T. senegalensis is the sister group of this clade with higher support values (pp> 0.90). The branch-site test identifed positive selection on T. inunguis in the 181st position of the ND4 amino acid gene (LRT= 6.06, p = 0.0069, BEB posterior probability = 0.96). The ND4 gene encodes one subunit of the NADH dehydrogenase complex, part of the oxidative phosphorylation machinery. In conclusion, our results provide novel insight into the evolutionary history of the Trichechidae during the Late Miocene, which was influenced by geological events, such as Amazon Basin formation.
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