Question

From a physiological perspective how are salmon similar to/different from marathon runners (muscles specifically)

Answer 1

Salmon, a member of superclass Osteichthyes, is primarily a marine fish but migrate to fresh water ( Anadromous) for spawning. They have to undergo several physiological changes to cope up with different osmotic conditions of the two water bodies as well as for swimming through such long distances.changes associated with osmotic adjustments are related with water uptake and removal of extra ions through gills. the changes associated with long distance swimming are result of integrated action of endocrinal and muscular activities as there is the case with marathon runners. Role of muscles is at high in every sort of movements like running, swimming, jumping, etc. Fish swim by contracting longitudinal white muscles (burst of activity like speed, jumping) and obliquely oriented red muscles (for sustainted activity). A marathon runners too need such orientations for forward propulsion of body as well as maintained support to the body, which is done by rhythmic actions of lower extremities. In both the cases, elevation of hormonal release from brain-pituitary-gonadal axis. increased level of testosterone imposes anabolic effects, thus increasing deposition of protein everywhere in the body, especially in muscles. Oxygen debt in muscles are overcome through increased breathing rate.Increased secretion of Glucocorticoids,Cortisol, from adrenal gland during long and persistent muscle activities help to maintain increased level of glucose in blood to make it readily available as energy source for muscle.