Anhingidae consists of one Genus Anhinga, and four species of Darters or Snakebirds. They are closely related to Phalacrocoracidae (Cormorants) and are distant relatives of Pelicans, Frigatebirds and Tropicbirds. Some authors place the Genus Anhinga in the Phalacrocoracidae family and group them all together, with Pelicans, Frigatebirds and Tropicbirds in Pelecaniformes order. Anhinga are distributed throughout tropical, sub-tropical and and warm temperate regions. Darters feed on fish and mainly inhabit fresh water lakes, rivers, marshes and swamps. But they are also found in marine or brackish waters such as estuaries, bays, lagoons and mangrove swamps.

Anhingas or Darters are sleek and long-necked waterbirds, and they look like a sleeker copy of cormorants. The typical body length is 85–95 cm. The bill is long, sharply pointed, and bright yellow. The wings are relatively short and rounded, and the long tail is wedge-shaped when spread. The legs are placed well-back on the body. The sexes differ in both plumage and aspects of behavior. Male anhingas have an overall black body coloration, with white markings on the wings and neck. Females also have a black body, but a light-brown neck and head. Anhingas are skilled at flying and swimming, but are clumsy on land. Like cormorants, anhingas sit low in the water because of their dense bones and feathers that get wet when immersed.

The four species of Anhingidae are: American Anhinga (Anhinga anhinga), Oriental Darter (Anhinga melanogaster), Australian Darter (Anhinga novaehollandiae) and African Darter (Anhinga rufa). Only one species of Darters is found in India.

Oriental Darter  (Anhinga melanogaster) - widespread resident