AN INTRODUCTION TO RIVER DOLPHIN SPECIES - Biology, Evolution and Conservation of River Dolphins Within South America and Asia - page 14

different breeding populations and there are several different geographic genetic lineages of
this species living together within larger populations (see Ruiz-García's chapter 8 & Vianna
et al.'s chapter 6). In chapter 8, the bufeo is described for the first time in analytical detail,
and the micro-genetic structure of populations within the Napo and Curaray rivers of the
Peruvian Amazon are discussed with the help of DNA microsatellite analysis. The results
support that this river dolphin has a social reproductive system. In fact, on January 1, 2003,
Ruiz-García´s team captured a female in the Tiphisca Paucar lagoon (Canal del Puhinauva,
Peruvian Amazon). Upon analysis of her constitution in a wooden research boat, the research
team noticed that she exhibited some health problems and the team decided to liberate her in
another section of the river that might be more conducive to her health. Immediately after she
was brought on board, a group of five or six botos persecuted the boat with aggressive
behavior and emitted intense vocalizations. They swam circles around the boat until the
researchers released the female. The scene was incredible to experience and can be typical of
a species that displays cooperative and social behavior. In chapter 9, Ruiz-García´s provides a
new explanation of river colonization by Inia that has the central Amazon River as the
probable origin of its expansion.
The pink river dolphin is probably the most secure of all the river dolphin species. Still,
there are multiple threats to this species such as incidental catch, construction of dams (da
Silva, 2002), direct hunting for genital organs (Best & da Silva, 1989), pesticides and mercury
(Rosas & Lehti, 1996). Scientists are attempting to obtain new information to help
conservation biologists by the analysis of carcasses that were the result of threats such as
incidental capture. For example, Castellanos-Mora et al.'s chapter 5 addresses how the age of
accidentally killed dolphins can be determined by craniometric and morphometric analyses, a
relationship that has not been well-studied in cetacean species. Other threats to this species
include freshwater pathogens. Martinez-Agüero et al.'s chapter 7 discusses the class II DQB
major histocompatibility complex (MHC) gene of pink river dolphins and how it exhibits a
high degree of polymorphism which may suggest an adaptive response to these pathogens.
This species is classified as vulnerable by the IUCN and listed in appendix II of the
Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES).
As mentioned previously, although this species of river dolphin has a wide distribution
range, and is probably the least threatened of the strict river dolphins, it is never-the-less still
threatened by several anthropogenic activities. Here are two brief field accounts by Ruiz-
García's research team that attest to these threats. In October 2003, they obtained three
decomposed carcasses of Inia geoffrensis at the Javarí River in the Peruvian and Brazilian
Amazon frontier. The animals, three large males, were partially eaten by ―mota‖ and had been
deposited in the Peruvian bank of this river by Brazilian ―colonos‖ fishermen. These dolphins
were purposefully killed and left to rot to attract small catfishes (mota‖- Calophysus
macropterus ), an event all too common in some Colombian and Brazilian Amazon rivers. In
another incident, Ruiz-Garcia interviewed a ―witch‖ who commented that Inia vaginas were
employed for love charms. The witch stated ―a little piece of the vagina is cut off and heated
in water until ebullition (or in fire). During this process, the fat of the piece is obtained and
mixed with aromatic alcoholic substances. A woman who desires to marry a specific man, a
man not cooperating with the plan, touches the prepared concoction on three points of the
man's face without his knowledge. In two or three months, the woman and the man will be
married.‖ Demand for dolphin parts, such as these by some indigenous people, bolster the