Black jaguars are mainly found in Central and South America particularly in the dense rainforest of Amazon Basin where the dark coloration gives them better camouflage in the dimly lit conditions.
A black jaguar is the same species as a normal-colored jaguar with melanistic coloration causing the fur of the animal to be very dark or black. Melanism occurs because of a dominant gene mutation of the jaguar. The melanistic trait is a result of heredity. Black jaguars can produce both black and fair-colored cubs, but fair-colored jaguars produce only fair-colored cubs when bred together. The jaguar mutation gene is not completely dominant. A black jaguar with two copies of the gene are darker than a jaguar with just one copy whose coat color may appear to be dark charcoal rather than black. Melanism is thought to be a favorable evolutionary mutation for jaguars.
Black jaguars are usually larger in size than black leopards. They weigh up to 250 pounds (113 kg). They often kill smaller animals by slapping on their head which may break the animalís skull. Unlike most of other big cats, black jaguars spend a lot of time in the water. They are excellent swimmers and often hunt in water too. Similar as black leopards, black jaguars are also good climbers.
Like the black leopard, the background color of the black jaguar coat is not truly black. It is more like very dark brown. It still has spotted marking on it. The spotted marking can be seen only from certain angle under bright sunlight. The rosettes, as the spotted patterns are called, are made up of small darker dots forming a circular shape. The additional spots inside the open rosettes exist only for jaguars but not for leopards.