D.S. Jordan, 1963
The Kurtiformes consist of two extant families of ray-finned fish, the Indo-Pacific Kurtidae, the nursery fish, with two species and the much more diverse and widespread Apogonidae, the cardinalfishes, the order is part of the Percomorpha clade and is regarded by many authorities as a sister taxon to the Gobiiformes.
Relationshiops and defining characteristics
A close relationship between the Kurtidae and Apogonidae was postulated based on the similarity of constituent parts of their dorsal gill arches and that in both groups the eggs are have filaments on the micropyle, which enable the eggs to form a mass. This mass is brooded in the mouth in the Apogonidae and borne on the supraoccipital hook of the two species in the Kurtidae. They also have horizontal and vertical rows of sensory papillae on their heads and bodies, which are often arranged in a pattern resembling a grid and similar patterns of sensory papillae can be observed in some species in the Gobiiformes. The two families comprising the Kurtiformes are recovered as sister groups in some molecular phylogenies, but as successive sisters to Gobiiformes in some molecular phylogenies.
Two extant families are classified under the order Kurtiformes: