The camel is the only mammal commonly identified as having oval rather than circular red blood corpuscles. These red blood cells, or erythrocytes, are shaped to keep circulating when the animal becomes severely dehydrated.
A camel’s oval erythrocytes can flow through narrowed blood vessels as water levels fall, and their flexible membranes tolerate major changes in blood concentration. This adaptation is especially valuable in deserts, where camels may go long periods without drinking and then consume a very large amount of water quickly. Their cells are less likely to rupture during those rapid osmotic changes.
This fact is part of a broader package of camel adaptations. A dromedary can lose a substantial share of its body mass to dehydration, while its kidneys and intestines conserve water efficiently. The hump is another frequent source of confusion: it stores fat, not water. Fat can provide energy and release some metabolic water, but the camel’s water is carried in its body fluids—not kept in the hump. “Camel” is the standard quiz answer, although biological sources may specify dromedary or camel species.