Skip to main content
×
×
Home

Body weight/length relationship and mass estimation using morphometric measurements in Amazonian manatees Trichechus inunguis (Mammalia: Sirenia)

  • Rodrigo S. Amaral (a1), Vera M.F. da Silva (a2) and Fernando C.W. Rosas (a2)
Abstract

This study defined the body weight/length relationship and an equation for body mass estimation using morphometric measurements on Amazonian manatees Trichechus inunguis (Mammalia: Sirenia). Total length (TL), maximum girth (MG) and body mass (M) were obtained from 91 captive Amazonian manatees (46 males and 45 females) of different ages, and TL and M were obtained from eight free-ranging Amazonian manatees (6 males and 2 females). The data were analysed by linear and multiple linear regressions. The maximum length and mass measured were 266.5 cm and 379.5 kg, respectively. The equation for body weight/length relationship was M = 0.00001070 * TL3.122 (r2 = 0.984) (Equation I) and no differences between sexes and between captive and free-ranging animals were found (P > 0.05). We calculated two more equations for mass estimation (Equation II: M = 0.00003284 * TL1.857 * MG1.106, r2 = 0.992; and Equation III: M = 1.506 + 0.00003477 * TL * MG2, r2 = 0.995), and the best equation (high correlation coefficient and low percentage of residues) was Equation III. Equation I provides the body condition of manatees, whereas Equation III is more accurate for estimating body mass. Both equations are important tools for management of captive and free-ranging Amazonian manatees.

Copyright
Corresponding author
Correspondence should be addressed to: R.S. Amaral, Departamento de Reprodução Animal—LDH/FMVZ/USP, R. Prof. Dr. Orlando Marques de Paiva, 87 Cidade, Universitária São Paulo05508-270—SP/Brazil email: rsamaral@usp.br
References
Hide All
Adulyanukosol, K., Prasittipornkul, C., Man-Anansap, S. and Boukaew, P. (2007) Stranding records of dugong (Dugong dugon) in Thailand. In Proceedings of the Fourth International Symposium on SEASTAR2000 and Asian Bio-logging Science, Phuket, 15–17 December 2007. Phuket: Kyoto University, pp. 5157.
Albuquerque, D.P. Jr (2003) Descrição histológica do tecido ósseo do domo timpânico, estimativa de idade e crescimento em cativeiro do peixe-boi da Amazônia Trichechus inunguis (Natterer, 1883) Mammalia, Sirenia. MSc thesis. Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil.
Ayres, J.M. and Best, R. (1979) Estratégias para a conservação da fauna amazônica. Acta Amazonica 9, 81101.
Best, R.C. (1984) The aquatic mammals and reptiles of the Amazon. In Sioli, H. (ed.) The Amazon, limnology and landscape ecology of a mighty tropical river and its basin. Dordhecht: Dr W. Junk Publishers, pp. 371412.
Bruyn, P.J.N. de, Bester, M.N., Carlini, A.R. and Oosthuizen, W.C. (2009) How to weigh an elephant seal with one finger: a simple three-dimensional photogrammetric application. Aquatic Biology 5, 3139.
Castellini, M.A. and Calkins, D.G. (1993) Mass estimates using body morphology in Steller sea lions. Marine Mammal Science 9, 4854.
De Mello, F.T., Vidal, N., Gonzalez-Bergonzoni, I. and Iglesias, C. (2009) Length–weight relationships of eight fish species from the lower section of the Uruguay River (Rio Negro, Uruguay). Journal of Applied Ichthyology 25, 128129.
Domning, D.P. (1982) Commercial exploitation of manatees Trichechus in Brazil, c. 1785–1973. Biological Conservation 22, 101126.
Edwards, F.K., Lauridsen, R.B., Armand, L., Vincent, H.M. and Jones, J.I. (2009) The relationship between length, mass and preservation time for three species of freshwater leeches (Hirudinea). Fundamental and Applied Limnology 173, 321327.
Husar, S.L. (1977) Trichechus inunguis. Mammalian Species 72, 14.
IBAMA (2001) Mamíferos aquáticos do Brasil, 2nd edition. Brasília: Instituto Brasileiro do Meio ambiente e dos Recursos Naturais Renováveis, 102 pp.
Ireland, D., Garrott, R.A., Rotella, J. and Banfield, J. (2006) Development and application of a mass-estimation method for Weddell seals. Marine Mammal Science 22, 361378.
IUCN (2010) IUCN Red List of Threatened Species. Gland: The World Conservation Union. www.iucnredlist.org. Accessed 10 February 2010.
McFadden, K.W., Worthy, G.A.J. and Lacher, T.E. Jr (2006) Photogrammetric estimates of size and mass in Hawaiian monk seals (Monachus schauinslandi). Aquatic Mammals 32, 3140.
Odell, D.K., Forrester, D.J. and Asper, E.D. (1978) A preliminary analysis of organs weights and sexual maturity in the West Indian manatee (Trichechus manatus). In Proceedings of the First Workshop on the West Indian Manatee in Florida, Orlando, 27–29 March 1978. Orlando: Florida Department of Natural Resources, pp. 5265.
Pinheiro, M.A.A. and Fiscarelli, A.G. (2009) Length–weight relationship and condition factor of the mangrove crab Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ucididae). Brazilian Archives of Biology and Technology 52, 397406.
Rosas, F.C.W. (1994) Biology, conservation and status of the Amazonian manatee Trichechus inunguis. Mammal Review 24, 4959.
Rosas, F.C.W., Barreto, A.S. and Monteiro-Filho, E.L.D.A. (2003) Age and growth of the estuarine dolphin (Sotalia guianensis) (Cetacea, Delphinidae) on the Paraná coast, southern Brazil. Fishery Bulletin 101, 377383.
Rosas, F.C.W., Marmontel-Rosas, M. and Best, R.C. (1985) Radio tracking evaluation of the Amazonian manatee. In Conclusiones de la Primera Reunión de Trabajo de Expertos en Mamíferos Acuaticos de America del Sur, Buenos Aires, 25–29 June 1984. Buenos Aires: Museo Argentino de Ciencias Naturales, p. 41.
Rosas, F.C.W. and Pimentel, T.L. (2001) Order Sirenia (manatees, dugongs and sea cows). In Fowler, M.E. and Cubas, Z.S. (eds) Biology, medicine, and surgery of South American wild animals. Ames: Iowa State University Press, pp. 352362.
Rosas, F.C.W., Rocha, C.S., Mattos, G.E. and Lazzarini, S.M. (2009) Body weight–length relationships in giant otters (Pteronura brasiliensis) (Carnivora, Mustelidae). Brazilian Archives of Biology and Technology 52, 587591.
Rosas, F.C.W., Silva, V.M.F. da, Sousa-Lima, R.S., d'Affonseca Neto, J.A. and Mattos, G.E. (2001) Adoption and growth of a captive Amazonian manatee (Trichechus inunguis) calf. In Abstract book of the Fourteenth Biennial Conference on the Biology of Marine Mammals, Vancouver, 28 November–03 December 2001. Vancouver: Society of Marine Mammalogy, p. 183.
Santos, E.P. (1978) Dinâmica de populações aplicada à pesca e piscicultura. São Paulo: Editora da Universidade de São Paulo, 129 pp.
Silva, V.M.F. da, Rosas, F.C.W. and Catanhede, A.M. (2008) Peixe-boi da Amazônia, Trichechus inunguis (Natterer, 1883). In Machado, A.B.M., Drummond, G.M. and Paglia, A.P. (eds) Livro Vermelho da Fauna Brasileira Ameaçada de Extinção. Belo Horizonte: Ministério do Meio Ambiente e Fundação Biodiversitas, pp. 816818.
Sivashanthini, K., Charles, G.A. and Thulasitha, W.S. (2009) Length–weight relationship and growth pattern of Sepioteuthis lessoniana Lesson 1830 (Cephalopoda: Teuthida) from the Jaffna Lagoon, Sri Lanka. Journal of Biological Sciences 9, 357361.
Trites, A.W. and Pauly, D. (1998) Estimating mean body masses of marine mammals from maximum body lengths. Canadian Journal of Zoology 76, 886896.
Vosseler, J. (1924) Pflege und haltung der Seekühe (Trichesus) nebst beiträgen zu lhrer biologie. Pallasia 2, 167180.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Marine Biodiversity Records
  • ISSN: -
  • EISSN: 1755-2672
  • URL: /core/journals/marine-biodiversity-records
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed