Angiotensin II is a potent vaso-active peptide that causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood.
The most reliable record of a Blue Shark at speed is 24.5 miles (39.4 kilometres) per hour for a 6.5-foot- (2-metre-) long individual. The Shortfin Mako (Isurus oxyrinchus) is probably the champion speedster among sharks.
Well, his speed in miles per hours sounds lower than it really is. According to ESPN, Michael Phelps' swimming speed capped off at about 6 miles per hour in 2010. If you're thinking 6 miles per hour sounds less than impressive, imagine trying to swim across a 6 mile-wide body of water in just an hour. Doesn't seem so easy now, right?