Pharyngeal jaw

Among the Pharyngealia refers to those parts of the gill arch skeleton ( see also pharyngeal arch ) of the fish, especially the Actinopterygii, which were concentrated increasingly on the course of evolution, the transport of food through the pharynx ( branchial gut, " throat ") and often their processing for better digestion ( as " chewing apparatus" ) to serve.

Phylogenetic development

You can clearly distinguish two stages of development. First, the posterior arch ( " fifth gill arch " ) developed a corresponding anterior dentition (from Devon ); from the Jurassic but also dorsally developed on the gill arches II to IV a complicated muscular apparatus ( with the dentate Pharyngobranchialie II -IV;. , the PhBr I serves as a connecting rod for the whole apparatus ), which allows prey much quicker and more efficient to devour. In particular, is a long ( paired ) muscle from the spine of meaning: the Retractor pharyngealium dorsalis (C. Holstvoogd 1965), which arises from the esophageal muscles.

Thus, the gill arches run for loops coordinated movements (such as a pantograph ), it is necessary that the dorsal ( " back hand " ) bone elements ( Epibranchialia ) directed against each other appendages form ( the uncinate processes ). The Acanthopterygii this is the case - in a similar manner ( autapomorph ) but even the mud fish in moray eels, carp, among others - The morays the Pharyngealia can be moved so far forward that they take packed with pine prey or from rip her pieces or can injure an affected enemy.

The mentioned ventral Pharyngealia act first on swallowing and " chewing" against each other or, in carp fishing, even against a gummy plate at the base of the skull. But are also dorsal Pharyngealia present, they interact with the ventral, which is now to strengthen their power fused ( Wrasses ) or merge ( puffer fish ) can. Rarely missing all Pharyngeal teeth ( sturgeons, Gonorynchiformes, Gyrinocheilidae ), but even rarer all Pharyngealia ( Flösselhecht ).