Fish
In some fish, a rete mirabile fills the swim bladder with oxygen, increasing the fish's buoyancy. A countercurrent exchange system is utilized between the venous and arterial capillaries. By lowering the pH levels in the venous capillaries, oxygen unbinds from blood hemoglobin. This causes an increase in venous blood oxygen concentration, allowing the oxygen to diffuse through the capillary membrane and into the arterial capillaries, where oxygen is still sequestered to hemoglobin. The cycle of diffusion continues until the concentration of oxygen in the arterial capillaries is supersaturated (larger than the concentration of oxygen in the swim bladder). At this point, the free oxygen in the arterial capillaries diffuses into the swim bladder via the gas gland.
The Rete Mirabile allows for an increase in muscle temperature in regions where this network of vein and arteries is found. The fish is able to thermoregulate certain areas of their body. Additionally, this increase in temperature leads to an increase in basal metabolic temperature. The fish is now able to split ATP at a higher rate and ultimately can swim faster.
Read more about this topic: Rete Mirabile
Famous quotes containing the word fish:
“Remember the waterfront shack with the sign FRESH FISH SOLD HERE. Of course it’s fresh, we’re on the ocean. Of course it’s for sale, we’re not giving it away. Of course it’s here, otherwise the sign would be someplace else. The final sign: FISH.”
—Peggy Noonan (b. 1950)
“Memory is a net; one finds it full of fish when he takes it from the brook; but a dozen miles of water have run through it without sticking.”
—Oliver Wendell Holmes, Sr. (1809–1894)
“I close my eyes and suck you in like a fire.
I grow. I grow. I’m fattening out.
I’m a kid in a rowboat and you’re the sea,
the salt, you’re every fish of importance.”
—Anne Sexton (1928–1974)