Biology Reference
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Figure 6. A mythic form of the
Inia geoffrensis
at the Colombian Amazon (copyright D.Alvarez & M.
Ruiz-García).
Inia boliviensis
(Bufeo, Pink River Dolphin)
Inia boliviensis
and
Inia geoffrensis
were only recently classified as separate species
based on molecular and morphological studies (Hamilton et al., 2001; Banguera-Hinestroza et
al, 2002; Ruiz-García et al., 2006, 2008). Comparatively,
Inia boliviensis
(Figures 7a & b) is
similar in color and in many characteristics to
Inia geoffrensis
, but it has more teeth, fewer
phalanges per manus, a wider rostral incision on its sternum, as well as other different
features (see Ruiz-Garcia's chapter 9). Ruiz-Garcia's chapter 9 also presents newly collected
mitochondrial DNA data of
Inia geoffrensis
and
Ina boliviensis
that suggests that the two
Inia
forms separated from each other only approximately 150,000 years ago, much more recent
than had been previously claimed.
Inia boliviensis
inhabit Bolivian rivers within the
Cochabamba, Santa Cruz, Beni, and Pando areas of the Amazon (see Aliaga-Rossel's chapter
3) and is geographically isolated by 400 km of waterfalls and rapids from other
Inia
populations in the Amazon's main stem. Their highest densities occur during rising and high
water (Aliaga-Rossel, 2002) and they have been observed in oxbow lakes, lagoons and rivers
and move between these areas even in times of low water. During high water they swim into
inundated areas and ephemeral rivers (Aliaga-Rossel, 2002; Aliaga-Rossel & Quevedo,
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