In most cases, the body of the toothy fish is covered with round scales. The sideline is reduced to a series of sensory pits. The pectoral fins sit high, the pelvic fins are on the chest or stomach. The caudal fin is rounded or straight. The caudal fin skeleton is symmetrical and has an epurale, an elongated, free-standing bone. The first postcleithrum, a cover bone of the shoulder girdle , is scale-like, a supracleithrum is always present. The margin of the protruding upper jaw is only formed by the premaxillary . The ploughshare (vomer) is usually present. The ectopterygoid is always absent, the metapterygoid in most cases. Both are wingbones of the fish. The number of vertebrae is 24 to 54, the number of Branchiostegal rays is between 3 and 7. Many species of the dentin have a distinct sexual dimorphism , with brightly colored males.
Systematics
To the order of the Zahnkarpflinge belong about 1150 kinds. In the following, the internal systematics of the tooth fish from Fishes of the World , a standard work on fish systematics, with additions according to Freyhof et al. and Bragança et al., and two cladograms are shown.
The systematics of the tooth parsons.
The cladogram shows the probable relationships between the different families of the dental pups.
↑ Bragança, PHN, Amorim, PF & Costa, WJEM: Pantanodontidae (Teleostei, Cyprinodontiformes), the sister group to all other cyprinodontoid killifishes as inferred by molecular data. In: Zoosystematics and Evolution. 94 (1), 2018, pp. 137–145, doi: 10.3897 / zse.94.22173 .
↑ David N. Reznick, Andrew I. Furness, Robert W. Meredith, Mark S. Springer: The origin and biogeographic diversification of fishes in the family Poeciliidae. PLOS ONE. 12 (3), 2017, e0172546, doi: 10.1371 / journal.pone.0172546 .
↑ Amorim, PF, & Costa, WJEM: Multigene phylogeny supports diversification of four-eyed fishes and one-sided livebearers (Cyprinodontiformes: Anablepidae) related to major South American geological events. PLoS ONE. 13 (6), 2018, e0199201, doi: 10.1371 / journal.pone.0199201 .