The darters or snake-birds are birds in the family Anhingidae. There are four living species. The darters are frequently referred to as snake-birds because of their long thin neck, which gives a snake-like appearance when they swim with their bodies submerged.
The darters are large birds with sexually dimorphic plumage. The males have black and dark brown plumage, an erectile crest on the nape and a larger bill than the female. The females have a much paler plumage especially on the neck and underparts. Both have grey stippling on long scapulars and upper wing coverts. The sharply pointed bill has serrated edges. The darters have completely webbed feet, and their legs are short and set far back on the body. Their plumage is somewhat permeable, like that of cormorants, and they spread their wings to dry after diving. Vocalizations include a clicking or rattling when flying or perching. During breeding adults sometimes have caw or hissing calls.