Dear Marmams,
I would like to announce the following article:
Growth curve of free-ranging Trichechus inunguis
Abstract
The objective of this work was to describe growth
curves for free-ranging Amazonian manatees in Brazil. Data analyzed
included age estimates and biometrics from 60 Amazonian manatees (33
males and 27 females) captured between 1993 and 2006 by local residents
of the mid-Solimões and Pirativa rivers, in Amazonia, and collected by
the Instituto de Desenvolvimento Sustentável Mamirauá and Centro
Nacional de Conservação e Manejo de Mamíferos Aquáticos/ICMBio. The
non-linear mathematical model used to analyze the data was the von
Bertalanffy's equation; two growth curves were calculated, one for
males L(t)male = 299.4[1–e-0.0897507(t+6.55696)], and one for females L(t)male = 256.1[1–e-0.23731(t+ 3.01921)].
Based on these equations, length at birth for the Amazonian manatee is
estimated at 133.2 cm (average = 113.0 cm; SD = 34.4 cm) for males, and
131.0 cm (average = 124.7 cm; SD = 22.0 cm) for females. Among the
males, the annual growth rate was 0.09 cm (95% CI: ± 0.002), with a
maximum length of 299.4 cm (95% CI: ± 2.039), while females presented a
growth rate of 0.24 cm per year (95% CI: ± 0.004), reaching up to 256.1
cm (95% CI: ± 0.4832) of total length. Even though von Bertalanffy's
equation is not commonly used for sirenians, and considering that when
previously applied it did not obtain satisfactory results, in this
study it proved adequate for the establishment of the growth curve for
free-ranging Amazonian manatees.
how to quote this paper
Vergara-Parente, J. E.; Parente, C. L.; Marmontel, M.; Silva, J. C. R. and Sá, F. B. Growth curve of free-ranging Trichechus inunguis . Biota Neotrop. Jul/Sep 2010 vol. 10, no. 3
http://www.biotaneotropica.org.br/v10n3/en/abstract?article+bn01410032010
ISSN 1676-0603.
Best regards,
Cristiano Leite Parente
Engenheiro de Pesca, DSc