The genus was introduced by Carl Linnaeus in 1758 in the 10th edition of his Systema Naturae.

[4] The genus contains the following eight species:[5] Unlike many kingfishers, all members of Alcedo are specialist fish-eaters.

They all have some blue feathers on their upper-parts and most species have a black bill.

The female generally has more red on the lower mandible than the male.

[7] The smallest species is the cerulean kingfisher which is around 13 cm (5.1 in) in length;[8] much the largest is Blyth's kingfisher with a length of 22 cm (8.7 in).