The coloring of the Atlantic spotted dolphin varies enormously as it grows, and is usually classified into age-dependent phases known as two-tone, speckled, mottled, and fused. Calves are a fairly uniform gray-white, with one or no spots. When they are weaned, speckling occurs, typically between 3 and 4 years and lasting for an average of 5 years. A juvenile is considered mottled when it develops merging gray and white spots on the dorsal surface and black spots on the ventral surface. This usually happens between age 8 or 9. A fused pattern is reached when dark and white spots are on both the ventral and dorsal sides. As the animal matures, the spots become denser and spread until the body appears black with white spots at full maturation.