The Kurtiformes consist of two extant families of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

, the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

Kurtidae ''Kurtus'' is a genus of percomorph fishes, called the nurseryfishes, forehead brooders, or incubator fish, native to fresh, brackish and coastal marine waters ranging from India, through southeast Asia to New Guinea and northern Australia. ''Ku ...

(consisting solely of two species in the genus ''

Kurtus ''Kurtus'' is a genus of percomorph fishes, called the nurseryfishes, forehead brooders, or incubator fish, native to fresh, brackish and coastal marine waters ranging from India, through southeast Asia to New Guinea and northern Australia. ''Ku ...

'') and the much more diverse and widespread

Apogonidae Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably ''Glossamia'') are found in fresh water. A h ...

(the

cardinalfishes Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably ''Glossamia'') are found in fresh water. A h ...

). The order is part of the

Percomorpha Percomorpha () is a large clade of ray-finned fish that includes the tuna, seahorses, gobies, cichlids, flatfish, wrasse, perches, anglerfish, and pufferfish. Evolution Percomorpha are the most diverse group of teleost fish today. Teleosts, an ...

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

and is regarded by many authorities as a sister taxon to the

Gobiiformes The Gobiiformes are an order of fish that includes the gobies and their relatives. The order, which was previously considered a suborder of Perciformes, is made up of about 2,211 species that are divided between seven families. Phylogenetic rel ...

Relationships and defining characteristics

A close relationship between the Kurtidae and Apogonidae was postulated based on the similarity of constituent parts of their dorsal

gill arch Branchial arches, or gill arches, are a series of bony "loops" present in fish, which support the gills. As gills are the primitive condition of vertebrates, all vertebrate embryos develop pharyngeal arches, though the eventual fate of these arc ...

es and that in both groups the eggs have filaments on the

micropyle Micropyle may refer to: * Micropyle (botany) In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (o ...

, 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 at least one of the two nursery fishes 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 (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 A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

, but others instead recover them as successive sisters to the Gobiiformes.

Families

Two extant families are classified under the order Kurtiformes: *

(

Bleeker Bleeker is a Dutch occupational surname. Bleeker is an old spelling of ''(linnen)bleker'' ("linen bleacher").Apogonidae Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably ''Glossamia'') are found in fresh water. A h ...

Günther, 1859 - cardinalfish

References

Ray-finned fish orders {{Kurtiformes-stub