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Rosas, Fernando César Weber
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1991 |
Peixe-boi da Amazônia, Trichechus inunguis. In: H. L. Capozzo & M. Junin (eds.), Estado de conservación de los mamíferos marinos del Atlantico Sudoccidental.
Informes y Estudios del Programa de Mares Regionales del PNUMA (United Nations Environment Programme) No. 138 (250 pp.): 178-181.
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Rosas, Fernando César Weber; Lehti, Kesä Kannikah; Marmontel, Miriam
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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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Rosas, Fernando César Weber
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2001 |
Order Sirenia (manatees, dugongs, sea cows). Biology. In: M. E. Fowler & Z. S. Cubas (eds.), Biology, medicine, and surgery of South American wild animals.
Ames, Iowa State Univ. Press (x + 536): 352-356.
–Forms part of Chap. 31 together with Pimentel, T.L., 2001.
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Marshall, Christopher D.; Maeda, Hiroshi; Iwata, Matsumitsu; Furuta, Masami; Asano, Shiro; Rosas, Fernando César Weber; Reep, Roger Lyons
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2003 |
Orofacial morphology and feeding behaviour of the dugong, Amazonian, West African, and Antillean manatees (Mammalia: Sirenia): functional morphology of the muscular-vibrissal complex.
Jour. Zool. 259(3): 245-260. 2 tabs. 7 figs. Mar. 2003.
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Amaral, Rodrigo de Souza; Rosas, Fernando César Weber; Viau, Priscilla; Nichi, Marcilio; Silva, Vera Maria Ferreira da; Oliveira, Cláudio Alvarenga
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2011 |
Monitoring salivary testosterone concentrations from captive Amazonian manatees (Trichechus inunguis): Is there seasonal pattern?
Reproduction, Fertility and Development 23(1): 181-181. DOI:10.1071/RDv23n1Ab156. Dec. 2010.
–ABSTRACT: Seasonality of reproduction in many nondomestic animal species appears to represent an accommodation to environmental variables, as food availability, in which influence reproductive success. Males can show a decrease of testicular size, sperm concentration, and serum concentration of testosterone because of food restriction. The Amazonian manatee (Trichechus inunguis, Mammalia: Sirenia) is a threatened aquatic mammal, endemic of the Amazon basin (South America), and is the only sirenian that occurs exclusively in fresh water. Although information is lacking about the reproductive endocrinology of free-ranging T. inunguis, they are considered seasonal breeders, with copulation and births occurring between December and July, coinciding with the increase in Amazon basin water levels and the period of most availability of food for the species (Best 1982 Biotropica 14, 76–78). Salivary steroid measurement is a noninvasive way to monitor steroid concentration, which is well correlated with the level of steroids in the serum. The aim of this study was to verify if testosterone concentrations of male T. inunguis kept in captivity, without variation of food availability, show a seasonal pattern. We used 4 adult male Amazonian manatees kept in captivity in the Laboratory of Aquatic Mammals of the National Institute of Amazonian Research–LMA/INPA, Brazil. They were fed all year with paragrass and vegetables, at not less than 8% of body weight per day. For sample collection, the pool was drained and saliva was collected from mouth mucosa using a metal spoon. Samples were collected weekly for 12 weeks in 2 periods (March–June and September–November). Salivary testosterone was measured by RIA for total testosterone using an adapted protocol previously validated for the species (Amaral et al. 2009 J. Zoo Wildl. Med. 40, 458–465) The data were analysed in a 3 × 2 factorial design, where the factors were month (each 4 weeks = 1 month) and period, using GLM test for repeated-measures. The means of salivary androgen levels were 28.80 ± 18.56 pg mL–1 and 30.77 ± 16.76 pg mL–1 for first and second periods, respectively. There were no significant main effects of month (P = 0.454), period (P = 0.607), or interaction between factors (P = 0.635). These results suggest that captive male Amazonian manatees apparently do not show reproductive seasonality. However, it is recommended to verify the existence of variation in testicular size and sperm concentration. This finding is important information for the future reproductive management of captive Amazonian manatee.
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Drummond de Mello, Daniela Magalhães; Silva, Vera Maria Ferreira da; Rosas, Fernando César Weber
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2011 |
Serum biochemical analytes in captive Amazonian manatees (Trichechus inunguis).
Veterinary Clinical Pathology 40(1): 74-77. 1 tab. DOI:10.1111/j.1939-165X.2011.00297.x March 2011.
–ABSTRACT: Background: Establishment of reference values for serum biochemical analytes is important for monitoring health and physiological status of captive animals.
Objective: The purpose of this study was to measure and report ranges for serum biochemical analytes in Amazonian manatees (Trichechus inunguis).
Methods: Blood samples were collected from 24 healthy captive Amazonian manatees that comprised a mixture of adults, subadults, and calves and males and females; serum analytes were measured and analyzed using a dry reagent bench-top chemical analyzer. Comparisons were made between sexes and with previously published values of closely related species.
Results: Medians and ranges (minimum–maximum) of values for the analytes were: lactate dehydrogenase (LDH), 151 (111–278) U/L (n=20); creatine kinase, 144 (76–315) U/L (n=11); alanine aminotransferase, 10 (2–28) U/L (n=18); aspartate aminotransferase, 14 (5–28) U/L (n=21); ?-glutamyltransferase, 47 (36–73) U/L (n=21); amylase, 1428 (1010–1874) U/L (n=21); alkaline phosphatase, 73 (36–141) U/L (n=19); total protein, 6.8 (6.2–8.0) g/dL (n=24); albumin, 3.3 (2.6–4.1) g/dL (n=21); cholesterol, 188 (101–399) mg/dL (n=21); triglycerides, 126 (60–236) mg/dL (n=21); glucose, 47 (22–69) mg/dL (n=21); urea, 43 (21–69) mg/dL (n=21); uric acid, 1.1 (0.5–1.8) mg/dL (n=22); creatinine, 2.2 (1.5–3.3) mg/dL (n=22); total bilirubin, 0.2 (0.2–2.0) mg/dL (n=21); calcium, 12.7 (10.2–18.6) mg/dL (n=24); iron, 282 (207–457) ?g/dL (n=13); and magnesium, 6.9 (4.3–8.9) mg/dL (n=20). With the exception of LDH, no differences were observed between sexes.
Conclusions: The ranges obtained in this study provide important preliminary estimates for concentrations and activities of serum analytes in Amazonian manatees until a larger reference interval study can be conducted.
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Guterres-Pazin, Michelle Gil; Rosas, Fernando César Weber; Marmontel, Miriam
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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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Kikuchi, Mumi; Silva, Vera Maria Ferreira da; Rosas, Fernando César Weber; Souza, Diogo; Miyazaki, Nobuyuki
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2012 |
The implications of turning behaviour performed by Amazonian manatees after release into the wild.
Journal of Ethology 30(1): 187-190. 1 tab. 2 figs. DOI:10.1007/s10164-011-0290-0. Jan. 2012.
–ABSTRACT: Sirenians have dichromatic colour vision and tactile hairs but have not developed underwater echolocation. Amazonian manatees (Trichechus inunguis) live in turbid water and it has been unclear how they understand their surroundings. In this study, we recorded the 3D movements of two captive-raised Amazonian manatees. The results revealed that the manatees always swam in a circular pattern. Both animals used slower, narrower turning motions as they approached the flooded forests, which are abundant in aquatic vegetation. Therefore, we suggest that these two manatees swam in a circular pattern to detect all directions of their surroundings especially using sensitive facial bristles.
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Amaral, Rodrigo de Souza; Rosas, Fernando Cesar Weber; Silva, Vera Maria Ferreira da; Nichi, Marcilio; Oliveira, Cláudio Alvarenga
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2013 |
Endocrine monitoring of the ovarian cycle in captive female Amazonian manatees (Trichechus inunguis).
Animal Reproduction Science 142(1-2): 84-88. 1 tab. 1 fig. Nov. 2013.
–ABSTRACT: The Amazonian manatee (Trichechus inunguis; Mammalia: Sirenia), a threatened aquatic mammal endemic to the Amazon basin, is the only sirenian that lives exclusively in fresh water. Information about the reproductive endocrinology of the Amazonian manatee is scarce; therefore, the aim of this study was to monitor salivary progesterone and estradiol patterns during the ovarian cycle in T. inunguis. Salivary samples were collected daily during a 12-week period of two consecutive years from two captive adult females. The salivary estradiol and progesterone were measured by enzyme immunoassay. The results were analyzed in an iterative process of excluding values that were higher than the mean plus 2 standard deviations until the basal values were determined. The interval between two peaks of salivary estradiol followed by a rise of progesterone was considered as one complete cycle for the calculation of the cycle length. We observed only three complete cycles in all samples analyzed. The cycle length ranged from 42 to 48 days (mean of 44.67 days). We also observed two distinct salivary estradiol peaks during all cycles analyzed, with the first peak occurring before the rise in salivary progesterone and the second occurred followed by a return to basal progesterone levels. This is the first in-depth study of the ovarian cycle in Amazonian manatees. Our results demonstrate that salivary samples can be a useful tool in the endocrine monitoring of this species and suggest that T. inunguis shows a peculiar hormonal pattern during the ovarian cycle, a finding that may have physiological and ecological significance in the reproductive strategy of these animals.
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Carmo, Talita Laurie Lustosa do; Amaral, Rodrigo de Souza; Rosas, Fernando Cesar Weber; D'Affonsêca Neto, José Anselmo; Reisfeld, Laura; Silva, Vera Maria Ferreira da
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2013 |
Changes in the blood parameters of the Amazonian manatee (Trichechus inunguis) after long-distance transportation.
Acta Scientiarum, Biological Sciences 35(4): 591-594. 1 tab. Doi: 10.4025/actascibiolsci.v35i4.20081 Oct.-Dec. 2013.
–Portuguese summ.
ABSTRACT: In this study we report the hematological, biochemical and hormonal parameters in a juvenile male Amazonian manatee measured before transport, immediately after transport, and during adaptation to a new facility. The animal was transported from Manaus, Amazonas State, Brazil, to São Paulo, São Paulo State, Brazil, (2,733 km) within 6 hours. Among all blood parameters analyzed, we observed obvious neutrophilia, lymphopenia, and increases in the neutrophil/lymphocyte ratio and serum glucose and aspartate aminotransferase (AST) levels, but these parameters subsequently returned to normal. These results suggest that transport and changes in the environment are temporary stressful events for Amazonian manatees. We, therefore, recommend monitoring the hematological and biochemical parameters before and after translocation to minimize the effects of handling stressors in this species.
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Franzini, André M.; Castelblanco-Martínez, Delma Nataly; Rosas, Fernando César Weber; Silva, Vera Maria Ferreira da
(detail)
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2013 |
What do local people know about Amazonian manatees? Traditional ecological knowledge of Trichechus inunguis in the Oil Province of Urucu, AM, Brazil.
Natureza & Conservação (Brazilian Journal of Nature Conservation) 11(1): 75-80. 1 tab. 3 figs. Supplementary material at abeco.org.br. July 2013.
–ABSTRACT: During 2005-2007, a series of interviews were carried out with the riverside populations of the Oil Province of Urucu (AM, Brasil). The main goal of this work was to characterize the knowledge of the inhabitants of this area regarding the Amazonian manatee (Trichechus inunguis) (listed as Vulnerable on the IUCN Red List). Interviews were conducted with 74 local inhabitants from 33 communities. Between 2004 and 2007, 20 poached or entangled Amazonian manatees were reported in the area. Poaching with harpoon is the principal cause of mortality, but manatees are also incidentally caught in fishing nets. Interviewers described details of manatee hunting techniques in the area. The trade of manatee meat, although currently forbidden by Brazilian laws, still occurs in the area. Data obtained from the interviews suggest a dietary preference of the manatee for at least 29 species of aquatic and semi-aquatic plants. The interviewed fishermen showed a sound knowledge of Amazonian manatee biology and behavior. This information may be important to assist future conservation plans in the Amazon.
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Amaral, Rodrigo S.; Rosas, Fernando César Weber; Silva, Vera M. F. da; Graham, Laura H.; Viau, Priscila; Nichi, Marcilio; Oliveira, Claudio A.
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2014 |
Seasonal variation in urinary and salivary reproductive hormone levels in Amazonian manatees (Trichechus inunguis).
Reproduction, Fertility & Development 27(7): 1065-1071. doi.org/10.1071/RD13334 Publ. online Apr. 2, 2014.
–ABSTRACT: The Amazonian manatee (Trichechus inunguis) is a threatened aquatic mammal endemic to the Amazon basin. The aim of this study was to evaluate the urinary and salivary reproductive hormone levels of captive Amazonian manatees collected during two seasons of the year. Salivary samples from four males and urinary and salivary samples from three females were collected during two seasons (March–June and September–November) over two consecutive years. Salivary testosterone in males was measured by radioimmunoassay and reproductive hormones in females (salivary progesterone and oestradiol and urinary progestogens, oestrogens and luteinising hormone) were measured by enzyme immunoassay. The data were analysed in a 2×2 factorial design, where the factors were year and season. There was no effect of year or season for salivary testosterone. All female hormones showed a seasonal effect (higher hormone levels during March–June than September–November) or an interaction between year and season (P < 0.05). These results strongly indicate the existence of reproductive seasonality in Amazonian manatees; however, apparently only females exhibit reproductive quiescence during the non-breeding season. Further long-term studies are necessary to elucidate which environmental parameters are related to reproductive seasonality in T. inunguis and how this species responds physiologically to those stimuli.
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Guterres-Pazin, Michelle Gil; Marmontel, Miriam; Rosas, Fernando César Weber; Pazin, Victor F. V.; Venticinque, Eduardo M.
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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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Bibliography and Index of the Sirenia and Desmostylia 