Fish.
To transport oxygen like every other animals.
red blood cells transport oxygen :)
Transporting oxygen in red blood cells is advantageous for larger animals because red blood cells contain hemoglobin, a protein that binds to oxygen molecules, allowing for efficient oxygen transport throughout the body. Hemoglobin enables larger animals to meet their higher oxygen demands by increasing the oxygen-carrying capacity of the blood, which is essential for sustaining their greater energy needs and larger size.
blood transport oxygen around the body
The absorb the nutrient from your body and transport blood and oxygen.
red blood cells
Red blood cells (erythrocytes) transport oxygen in the blood. Hemoglobin, a protein found within red blood cells, binds to oxygen and carries it from the lungs to the body's tissues.
Gnats do not have blood in them. They have a liquid called hemolymph, which serves a similar purpose to blood in other animals. Hemolymph helps transport nutrients and oxygen throughout the gnat's body.
oxygen
Red blood cells contain hemoglobin and transport oxygen
blood transports oxygen and nutrients
Blood transport oxygen.