AMAZON RIVER DOLPHIN: HIGH PHYLOPATRY DUE TO RESTRICTED DISPERSION AT LARGE AND SHORT DISTANCES - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 111

h and π (p < 0.05). Asterisks (*) indicate Bolivian haplotypes reported by Banguera-
Hinestroza et al., (2002) that were originally 7 haplotypes, but they have published (see
Figures 2 and 3 of their paper) and deposited in Genbank the haplotypes BA1 and BA5 as
identical sequences.
C ONCLUSION
Some general aspects can be retrieved from the diversity data of the Brazilian
populations. The higher haplotype diversity found on the Mamirauá location may be a result
of greater habitat diversity found on the reserve, as compared to the non protected Tefé area.
The Mamirauá reserve (MSDR, 64 o 45'W; 03 o 35'S) is a flooded land with many lakes and
intermittent channels, comprising 11.240 km 2 . It includes the Mamirauá Lake system (225
km 2 ) where many samples were collected. The reserve is situated between the juncture of the
Japurá and Solimões (Amazon) rivers, two large whitewater tributaries of the Amazon basin.
The MSDR is a floodplain area with a seasonal flood of 10-15 m in amplitude. Furthermore,
the reserve has been established since 1990, preserving a high diversity (>300 spp ) and
biomass of fishes (Crampton, 1999), which attracts a diverse community of piscivorous
predators, including Inia, a generalist fish predator (da Silva, 1983). The Tefé population
occurs in a dark transparent water environment, which is less common in that Amazon area
where the turbid water environment is widespread. The Tefé is a large, black water lake (125
km 2 ) but shallow, with a maximum depth of 20 m. The lake is connected to the Amazon
River by a narrow channel. Although the two Brazilian locations are close to each other, the
maternal lineages reveal a relatively low gene flow detected by the mtDNA HVSI ( ST =0.66,
Table 4), and no shared Cyt-b haplotypes. The distance between the mouth of the Tefé River
and the beginning of the Mamirauá Reserve (MSDR) is only 45 km and the results reveal a
low (or presently absent) female migration between these areas. A different situation is found
in other sympatric aquatic Amazonian mammals. The Amazonian manatee displays
haplotypes widely spread and a reduced population structure ( ST = 0.10 to 0.22) (Vianna et
al., 2006). Furthermore, the Amazon River dolphin Sotalia fluviatilis also displays a
significantly lower population structure ( ST = 0.29) (Caballero et al., 2007). The higher level
of population structure detected in Inia geoffrensis should be seriously considered in future
strategies for population management and species conservation, particularly those involving
translocation of animals.
The phylogeographic pattern observed in the analysis of control region mtDNA
haplotypes from Brazilian, Colombian and Bolivian populations described by Banguera-
Hinestroza et al., (2002) is still very remarking when adding our data and analyses. Our
results also support the occurrence of two ESUs, through the use of network (MJN) and tree
(NJ) reconstructions, as well as using SAMOVA (Dupanloup et al., 2002) and the Barrier
software (Manni et al., 2004). The separation of the Bolivian ESU can be likely due to a
barrier consisted by 200 km of rapids between Guajara-mirim and Porto Velho in Brazil (da
Silva, 1994), isolated since the end of the Pliocene and the beginning of the Pleistocene
(Pilleri et al., 1984).
The Brazilian haplotypes occupy an intermediate position between haplotypes of
Colombian Orinoco and Bolivian populations (Figure 2). Interestingly, our MJN analyses