Subject: Abstract on Manatees (fwd)

Mike Williamson (
Sun, 6 Sep 1998 09:14:18 -0400 (EDT)

Reply-To: Marine Mammals Research and Conservation Discussion
Subject: Abstract on Manatees (fwd)

A. I. Garcia-Rodriguez, B. W. Bowen, D. Domning, A. A. Mignucci-Giannoni,
  M. Marmontel, R. A. Montoya-Ospina, B. Morales-Vela, M. Rudin,
  R. K. Bonde, and P. M. McGuire.  1998.  Phylogeography of the West
  Indian manatee (Trichechus manatus):  How many populations and how
  many taxa?   Molecular Ecology 7(9): 1137-1150.


To resolve the population genetic structure and phylogeography of the West
Indian manatee (Trichechus manatus), mitochondrial (mt) DNA control region
sequences were compared among eight locations across the western Atlantic
region.  Fifteen haplotypes were identified among 86 individuals from
Florida, Puerto Rico, the Dominican Republic, Mexico, Colombia, Venezuela,
Guyana and Brazil.  Despite the manatee's ability to move thousands of
kilometres along continental margins, strong population separations
between most locations were demonstrated with significant haplotype
frequency shifts. These findings are consistent with tagging studies which
indicate that stretches of open water and unsuitable coastal habitats
constitute substantial barriers to gene flow and colonization.  Low levels
of genetic diversity within Florida and Brazilian samples might be
explained by recent colonization into high latitudes or bottleneck
effects.  Three distinctive mtDNA lineages were observed in an
intraspecific phylogeny of T. manatus, corresponding approximately to 1)
Florida (U.S.A) and the West Indies; 2) the Gulf of Mexico to the
Caribbean rivers of South America; and 3) the northeast Atlantic coast of
South America. These lineages, which are not concordant with previous
subspecies designations, are separated by sequence divergence estimates of
d=0.04-0.07, approximately the same level of divergence observed between
T. manatus and the Amazonian manatee (T. inunguis, n= 16).  Three
individuals from Guyana, identified as T. manatus, had mtDNA haplotypes
which are affiliated with the endemic Amazon form T. inunguis.  The three
primary T. manatus lineages and the T. inunguis lineage may represent
relatively deep phylogeographic partitions which have been bridged
recently due to changes in habitat availability (after the Wisconsin
glacial period, 10 thousand years BP), natural colonization, and
human-mediated transplantation.

Please address Reprint Requests to:

Angela Garcia

USGS-Biological Resources Division
Sirenia Project
412 NE 16th Av, Room 250
Gainesville, FL 32601

Phone: (352)372-25-71
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