Wednesday 15 July 2009 Amazon River Dolphin - Pretty in Pink

The Amazon river dolphin (Inia geoffrensis) was first officially described by Henri Marie Ducrotay de Blainville in the early 19th Century and was given the scientific name Inia geoffrensis. However, it is commonly referred to as simply the boto. This species exhibits clear sexual dimorphism with adult males reaching lengths of nearly 2.5 meters (8.2 feet) and weighing up to 185 kilograms (407lb). Females are rarely found to be longer than 2.15 meters (7 feet) and typically weigh around 40 kilograms (88lb) less than their male counterparts.

Another common name for the boto is the pink dolphin. However, pink coloration is generally only present to any significant degree in males of the species, and is the result of scar tissue formation. Competition between males for the possession of females is intense, leading to battles in which both competitors are commonly wounded. Such fierce competition between males may explain why females with young calves tend to avoid the deep freshwater territories of males, preferring the shallower flood plains. In fact, contact between females and males is largely confined to the mating season in late October.

Botos are the largest of the five species of river dolphin and are native to Brazil, Bolivia, Colombia, Ecuador, Peru and Venezuela. In much of its territory the Amazon river dolphin is sympatric with the Tucuxi, however, the two are easily distinguishable. The Tucuxi is similar in appearance to the perhaps more familiar bottle-nosed dolphin. The boto, on the other hand, has an elongated jaw filled with up to 30 specialised teeth for catching and crushing fish. Jaw elongation is thought to have evolved in response to the unique set of seik.php?idsite=28" style="border:0" alt="" />