Mamirauá Reserve is an important home and refuge for this beautiful species of dolphin
In last week’s post I wrote on the famous pink dolphins and how different they are from other dolphin species. In Mamirauá these differences are evident by the presence of another dolphin, the “gray dolphin” better known by the popular name tucuxi.
Most people who come to the Amazon have heard of it and hope to see the pink dolphin on their visits, but they are surprised to see another dolphin, so similar to the marine ones, jumping in the rivers of the region. Tucuxi appeared more recently in the Amazon, possibly 2.5 million years ago, coming from the Atlantic Ocean and maintained the appearance very close to that of its marine relatives. Currently, two species of tucuxis are recognized: Sotalia guianensis, which occurs in marine and estuarine areas (areas where rivers meet with the ocean) and Sotalia fluviatilis, which inhabits freshwater environments, including around Uakari Lodge.
Sotalia fluviatilis is a species of small dolphins, one of the smallest in the Delphinidae family, with an average length of 1.5 meters and a weight of around 50 kg. The size and anatomy, including the classic torpedo shape, of these porpoises makes them fast swimmers and skilled jumpers. Watching the acrobatics of these animals is incredible and the memories are usually recorded in the mind, since registering in a photo is a difficult task, I myself (who spend good hours in the field) do not have pictures of the tucuxis (in fact I have many attempts at photos) LOL).
Unlike the pink dolphins, the tucuxis do not have sexual dimorphism (when males and females have physical characteristics – not related to Organs sexual organs – different) evident. But the differences between the tucuxi and the pink dolphin go beyond the physical ones: these are solitary while the tucuxis live in groups, of up to normally six individuals, but clusters of 40 animals have already been reported.
Like all dolphins, the tucuxis have an echolocation organ called melon (located on the front of the skull), this emits high frequency sounds that reach objects in the environment and the echo resulting from this interaction goes back to the dolphins, allowing the brain forms images.
The greatest threats to these mammals are the garbage deposits that can contaminate the water in which they live and also the prey from which they feed, loss of habitat and human interference in this (especially construction of hydroelectric plants along the rivers) and mainly by-catch. in fishing nets. Fortunately, there are still protected areas like the Mamirauá Sustainable Development Reserve, which in addition to being important refuges and nursery areas for these and other aquatic animals, still involves traditional populations, scientists and tourists in the conservation of these, after all, the preservation of the Amazon is urgent and needs as many hands as we can get.
. Texto: Cynthia Lebrão
. Imagens: Gui Gomes