213
(Azevedo et al. 2005) while in the Baía de Sepetiba, S. guianensis occurred in areas
with depths varying between 3 and 30 m (Simão and Poletto 2002).
Our results allied to other opportunistic sightings of the species, during the summer months, support the affirmation that the estuarine dolphin occurs frequently in
this poorly studied stretch of the coast.
These factors associated with the short extension of the continental platform in
this stretch of the Bahia State, offer a mosaic of environments, where beyond
coastal/ estuarine, widely reported as area of occurrence of the species, exists also
the oceanic/ pelagic where we evidence that the specie also frequents.
The presents observations in relation to the distribution and depth differ from
world-wide literature on the occurrence of the Steno bredanensis, rough-toothed
dolphin, that usually record the species occurring in deep waters, out of the edge of
the continental platform (Leatherwood and Reeves 1983; Miyasaki and Perrin
1994). On the other hand, S. bredanensis is registered occurring in coastal flat
waters in Brazil (Lodi and Capistrano 1990; Ott and Danilewicz 1996; Flores and
Ximenez 1997; Lodi and Hetzel 1998, 1999; Wedekin et al. 2004).
Considering that the continental platform of the state of Bahia, Brazil, is relatively narrow, we could say that S. bredanensis in the north coast of Bahia possibly
have preferences for shallow and coastal waters. In the Bank of Abrolhos and
throughout the coastal archipelago of the Biological Reserve of Arvoredo in the
state of Santa Catarina, S. bredanensis also occurs in shallow waters, what probably
it can be a standard for the coast of Brazil (Lodi and Hetzel 1998).
Group size varied could be characterized as small, from 1 to 6 individuals, when
compared to records of more than 50 animals registered in tropical eastern Pacific
(Leatherwood et al. 1988), five groups in Japanese waters involving of 23–53 animals, or even smaller groups of 10–20 that seem to be more usual (Miyasaki and
Perrin 1994). Our study corroborates a previous revision about the species in
Brazilian waters, that suggests group size of S.bredanensis between 1 and 10 animals
(Lodi and Hetzel 1998).
In Brazil, the Stenella clymene, have been early registered for Santa Catarina and
northeast region (Simões-Lopes et al. 1994; Zerbini et al. 2004).
The depth data of in this work contradict with the literature (eg. Moreno et al.
2005; Davis et al. 1998; Bastida et al. 2007), that suggests this species of dolphin as
having preference for deep waters, generally of 1000–4500 m, beyond the continental shelf. According to Davis et al. (1998), sightings of S. clymene whitin of the
continental shelf are not common.
Groups of S. clymene generally are numerous, however in the Brazilian coast it
may be more variant, from about 8 to 300 individuals (Moreno et al. 2005). This
species was also considered as the most frequent stranded dolphin species between
2000 and 2002 in Northeastern Brazil (Alvite et al. 2004), what can coincide with
the period of sightings made for the research in the coast of Bahia.
There is no sighting record for the spotted dolphin, Stenella frontalis, in the coast
of Bahia, first considered as an hiatus of distribution to the spotted dolphin (Moreno
et al. 2005), therefore this work reports on the first register of sighting for the species
in this area.
8 Opportunistic Sightings of Dolphins (MAMMALIA, CETACEA, DELPHINIDAE)…
(Azevedo et al. 2005) while in the Baía de Sepetiba, S. guianensis occurred in areas
with depths varying between 3 and 30 m (Simão and Poletto 2002).
Our results allied to other opportunistic sightings of the species, during the summer months, support the affirmation that the estuarine dolphin occurs frequently in
this poorly studied stretch of the coast.
These factors associated with the short extension of the continental platform in
this stretch of the Bahia State, offer a mosaic of environments, where beyond
coastal/ estuarine, widely reported as area of occurrence of the species, exists also
the oceanic/ pelagic where we evidence that the specie also frequents.
The presents observations in relation to the distribution and depth differ from
world-wide literature on the occurrence of the Steno bredanensis, rough-toothed
dolphin, that usually record the species occurring in deep waters, out of the edge of
the continental platform (Leatherwood and Reeves 1983; Miyasaki and Perrin
1994). On the other hand, S. bredanensis is registered occurring in coastal flat
waters in Brazil (Lodi and Capistrano 1990; Ott and Danilewicz 1996; Flores and
Ximenez 1997; Lodi and Hetzel 1998, 1999; Wedekin et al. 2004).
Considering that the continental platform of the state of Bahia, Brazil, is relatively narrow, we could say that S. bredanensis in the north coast of Bahia possibly
have preferences for shallow and coastal waters. In the Bank of Abrolhos and
throughout the coastal archipelago of the Biological Reserve of Arvoredo in the
state of Santa Catarina, S. bredanensis also occurs in shallow waters, what probably
it can be a standard for the coast of Brazil (Lodi and Hetzel 1998).
Group size varied could be characterized as small, from 1 to 6 individuals, when
compared to records of more than 50 animals registered in tropical eastern Pacific
(Leatherwood et al. 1988), five groups in Japanese waters involving of 23–53 animals, or even smaller groups of 10–20 that seem to be more usual (Miyasaki and
Perrin 1994). Our study corroborates a previous revision about the species in
Brazilian waters, that suggests group size of S.bredanensis between 1 and 10 animals
(Lodi and Hetzel 1998).
In Brazil, the Stenella clymene, have been early registered for Santa Catarina and
northeast region (Simões-Lopes et al. 1994; Zerbini et al. 2004).
The depth data of in this work contradict with the literature (eg. Moreno et al.
2005; Davis et al. 1998; Bastida et al. 2007), that suggests this species of dolphin as
having preference for deep waters, generally of 1000–4500 m, beyond the continental shelf. According to Davis et al. (1998), sightings of S. clymene whitin of the
continental shelf are not common.
Groups of S. clymene generally are numerous, however in the Brazilian coast it
may be more variant, from about 8 to 300 individuals (Moreno et al. 2005). This
species was also considered as the most frequent stranded dolphin species between
2000 and 2002 in Northeastern Brazil (Alvite et al. 2004), what can coincide with
the period of sightings made for the research in the coast of Bahia.
There is no sighting record for the spotted dolphin, Stenella frontalis, in the coast
of Bahia, first considered as an hiatus of distribution to the spotted dolphin (Moreno
et al. 2005), therefore this work reports on the first register of sighting for the species
in this area.
8 Opportunistic Sightings of Dolphins (MAMMALIA, CETACEA, DELPHINIDAE)…