|of cartilage fish|
Controversies in systematics
the usual Lehrmeinung sees the cartilage fish as a group of sisters of the Knochenkiefermäuler (Osteognathostomata) within the Kiefermäuler. This hypothesis was placed lately repeated by comparative genetic investigations by hypotheses in question, after those the cartilage fish withinthe Osteognathostomata developed and either with the Strahlenflossern or the Fleischflossern in a relationship of group of sisters.
That has however serious consequences regarding the established evaluation of many outside characteristics. Thus would have the direct common move forward the three Taxa for examplea lung swimming blister organ and knöcherne Kiemendeckel had, which were again reduced therefore with the cartilage fish.
From evolutionary view one can interpret many characteristics of the cartilage fish as adjustment to the way of life and the habitat in the deep sea: like that would be thoseReduction of the bone skeleton to the decrease of the specific weight, which takes place development of specialized electrical sensory organs from lack of light. Internal fertilization and the relative small number of descendants are apart from other morphologic and physiological characteristics further indications that these characteristics in the sensea Typogenese developed for additives. Therefore the rezenten sharks, which settle today flat of territorial waters, would secondarily have opened this habitat.
systematics within the cartilage fish
- Plattenkiemer (Elasmobranchii)
- sea-cats (Holocephali), alsoChimären (Chimaera) called
details under systematics of the cartilage fish.
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