Functional anatomy and movement co-ordination of the respiratory pump of the carp (Cyprinus carpio L.).

The evaluation of the movement co-ordination of fish respiratory systems has attracted many investigators (Baglioni, 1907, 1910; van Dobben, 1935; Kirchhoff, 1958; Willem, 1931, 1940, 1947; Woskoboinikoff, 1932). For a long time the theories of the functioning of the system were only based upon anatomical data. It is hardly surprising that this has led to conflicting theories in many cases where the function of a muscle was deduced from its origin and insertion only, without knowledge of the timing of its activity, although a general and superficial picture of course may be gained in this way. An exact analysis of muscle activity can be made nowadays with electrophysiological techniques (Ballintijn, 1965,1969a, b\ Ballintijn & Hughes, 1965; Hughes & Ballintijn, 1965; Hughes & Shelton, 1962) with which the exact timing of muscular contraction can be recorded. However, to understand the movement co-ordination as a whole a complete knowledge of the functional anatomy of the respiratory system remains indispensable. The visceral skeleton, which performs the respiratory movements under influence of the contraction of a varying number of head muscles, is a very complicated structure. It consists of bone arches and of bones which in many places articulate and influence each other by lever action and by ligaments. Through this the effect of the contraction of a muscle spreads much farther than at first sight would be expected. In the present paper an anatomical description of the muscular and skeletal system of the carp head, as far as it has a respiratory function, will be given. Further, an outline of the action of the muscles based upon the anatomical data will be presented. Finally, the coupling possibilities of the visceral skeleton by which movements spread far over the system will be analysed in detail. This analysis will serve as the basis for a subsequent paper on the muscle co-ordination of carp respiration (Ballintijn, 1969 a).