Morphological Basis of the Pectoral Fin Flutter of Embryonic Atlantic Salmon ( Salmo salar )

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Peterson, R. H., Power, J., Martin-Robichaud, D. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1991
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Fulcrum; Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1139/f91-261; http://www.nrcresearchpress.com/doi/pdf/10.1139/f91-261

The pectoral fin of embryonic Atlantic salmon (Salmo salar) flutters rhythmically through most of the early development, probably to promote water currents near embryonic respiratory surfaces. A descriptive mechanical model of the anatomical basis of the fin movements involves four components. The basal coraco-scapular complex serves as a fulcrum for fin movements. The actinost forms a thin vane, which is alternately abducted and adducted by two opposing muscle groups originating on the coraco-scapular cartilage and inserting distally on the actinost. The last component, the fin membrane, moves as a result of travelling waves passing distad as a result of flexion of the actinost — a "whiplash" type of motion. The first five spinal nerves may be involved in generation of the rhythmic flutter.