astronomy-to-zoology:

Brazilian Merganser (Mergus octosetaceus)

…a Critically Endangered species of typical merganser (Mergus spp.) that is native to central-south Brazil and adjacent regions in Paraguay and Argentina. Like other mergansers M. octosetaceus is a predator and feeds mainly on fish, using its serrated bill to hold on to its slippery prey. Brazilian mergansers are also known to eat molluscs and insects as well. Brazilian mergansers typically feed in groups and will catch fish by diving. Brazilian mergansers are typically seen near rivers and streams with rapids and excess vegetation. 

Currently Mergus octosetaceus is listed as Critically Endangered. This is mostly due to the fact that they are very sensitive to habitat degradation and loss due to human actions. And as such silting of rivers is becoming a major threat to their survival. 

Classification

Animalia-Chordata-Aves-Anseriformes-Anatidae-Merginae-Mergus-M. octosetaceus

Image: Prof. Sávio Freire Bruno