Physical Characteristics Physical Characteristics A. Size. Adult West Indian and West African manatees average about 10 ft. Large individuals may reach lengths of up to 13 ft. Average adult weights are approximately 800 to 1200 lb. Large individuals have been known to weigh up to 3500 lb.
Females are generally larger than males.
Amazonian manatees are the smallest of the three species. They are shorter and more slender. The longest recorded specimen measured 9.2 ft. One particularly large specimen weighed 1058 lb. B. Body shape.