MOLECULAR ECOLOGY AND SYSTEMATICS OF SOTALIA DOLPHINS - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 268

A (PA)

2-1

AM2

4-1 *

2-6

1-1 *

B (PA/BA)

D (ES/RN)

3-3

C (S/SE)

AM5

E (BA)

3-1 *

AM4

1-2 *

2-5 F (RN)

AM3

H (CE) G (ES)

2-2 *

1-3

J (PA)

I (PA/RN/BA)

K (PA)

AM1

2-4 N (PA)

3-2

1-5

M (PA/CE)

L (PA)

O (PA)

1-6

2-3 *

P (BA)

Figure 5. Parsimony network of haplotypes from the Brazilian coast, with nested clade design. Ovals
represent missing intermediaries. Clades with significant associations (P < 0.05) are marked with an
asterisk. Hierarchical level is denoted as 1-x for first level, 2-x for second, etc, where x identifies each
clade. AM: Amazonas ( S. fluviatilis ). S. guianensis - PA: Pará; CE: Ceará; RN: Rio Grande do Norte;
BA: Bahia; ES: Espírito Santo; S/SE: South-Southeastern (Rio de Janeiro, São Paulo, Paraná and Santa
Catarina). Adapted from Cunha (2007).

Therefore, both the phylogenetic and NCA approaches supported the same conclusion:
riverine and marine populations of Sotalia are deeply divergent. This result, along with
distinct ecological and geographical distributions and the morphometric differentiation
observed between them (Monteiro-Filho et al., 2002), led Cunha et al. (2005) to conclude that
marine and riverine Sotalia belonged to different species. At least three criteria for the
recognition of taxa as distinct species were fulfilled by those data (morphological and
molecular population aggregation analysis, cladistic haplotype aggregation and Templeton's
test of cohesion - Sites & Marshall, 2003).
In 2003, an international workshop on the molecular systematics of Cetaceans recognized
that there was, in the field, a ―traditional tendency to err in the direction of avoiding
designating too many taxa rather than making sure that all potentially recognized taxa have
been designated'' (Reeves et al., 2004). As a consequence, guidelines for the recognition of
full species were established. According to the Workshop's guidelines, an argument for
species status should be accepted only when there were at least two independent primary lines
of evidence for its existence, such as morphology and genetics (Reeves et al., 2004).
Therefore, together, the results presented by Monteiro-Filho et al. (2002) and Cunha et al.
(2005) fulfilled those guidelines. Marine and riverine species of Sotalia could be separated
not only on the basis of two primary types of evidence (morphology and genetics,
respectively), but also of secondary ones (i.e., distribution and ecology). Based on priority