Gill raker

The gills of the fish Reuse is an organ system of toothed appendages of the branchial arches, which serves to separate food and water breathing each other. These extensions are as Branchiospinen (among rakers ) denotes, each arranged on the gill arches to series spines hot Branchioctenien ( combs ).

In vertebrates and their ancestors, whose vorsilurische forms are known only very inadequately, there is a pharynx ( gills and intestine ), that is, the foregut was following the oral cavity columnar breakthroughs (including through the body skin) to the outside, which makes it possible plankton filter out as food and swallow the same ( see also lancelets, tunicates ). Once the ancestors of vertebrates were a few millimeters in size and was no longer able them skin respiration, the gills and intestine offered as an additional respiratory organ. However, this requires an appropriately functioning vascular system - the heart was in a situation just "before" this pharynx ).

All water -breathing animals with jaws have dentate on the inner side of the gill arches extensions to separate food and water breathing each other. In fish that gobble large, but dead prey, the fish trap may regressed down to traces (that also applies to predatory fish such as barracuda, which kill their prey before devouring ), otherwise it is always necessary, for example to live prey because to prevent escape through the gill slits.

The densest Reuse naturally have plankton filter ( among others basking shark, whale shark, Megamouth, Manta, paddlefish, herring, anchovies, whitefish, Cyclothone microdon, Indian mackerel). A big mouth has in such fishing then point out that, if necessary, to " jam filters" can go (English ram feeding ) (eg, Indian mackerel). The Reuse consists of stiff - fibrous, cartilaginous or bony, often moving processes of the gill arches of different size, shape and arrangement ( branched ) - one row at the front and at the rear of the column. Through their entanglement the Reuse rays also stabilize the gills and intestine. You are always positioned so that the columns do not clog ( cross-flow filtration ): the food particles slide off and be the esophagus towards " washed ", where they are grabbed by the throat teeth, often crushed (especially in carp -like ). The column 4 to 5 arc is closed to often ( connective tissue ). Only very rarely are spines on the hyoid arch, but the front are extended on the first gill arch often.

In the lower genuine bony fish ( Teleostei ) with Mikrophagie ( feeding on micro-organisms ) the gills Reuse is functionally usually supplemented by the paired Epibranchialorgan ( at the upper rear end of the pharynx ): it produces mucus, stick to the small creatures to be more easily swallowed. Most rich Branchiospinen in this organ into it, so that the food particles in some cases can be crushed, probably in order to " assess taste ". See also: Heterotis niloticus, True herring, anchovies, Argentinidae, Alepocephalus rostratus, Coregonus, Gonorynchus and Citharinidae. Higher Teleostei with plankton and detritus - eating have analog slime -producing organs in the skin gills and intestine, eg the Mugilidae.