MOLECULAR ECOLOGY AND SYSTEMATICS OF SOTALIA DOLPHINS - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 277

C ONCLUSIONS AND P ROSPECTS

This chapter reviewed the latest results on the molecular systematics and ecology of
Sotalia dolphins. Some of the issues still require investigation, but several important results
have been obtained in those fields during the last few years.
Unquestionably, the most remarkable finding to date was the elucidation that riverine and
marine ecotypes of Sotalia are different species. Molecular markers were fundamental to
settle the issue of specific differentiation between S. fluviatilis and S. guianensis . The impact
of that discovery can be appreciated by considering that all articles published since the work
of Cunha and co-workers (2005) accepted the revalidation of S. guianensis (22 articles - Web
of Knowledge search on October, 2008). A major consequence of the split of Sotalia species
is the need for reassessment of their conservation status, in recognition of the different
conservation requirements of both species. The discovery of an exclusively freshwater habit
for S. fluviatilis indicates that it should have its conservation priority raised. Secondly, the
impact of non-natural mortality need to be re-evaluated for each MU of S. guianensis across
its entire range, and conservation plans must be devised for those MU that show signs of
endangerment.

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