Charybdis helleri lives throughout the tropical Indo-Pacific area from the east coast of Africa to Hawaii. It also has become established in the eastern Mediterranean Sea by traversing the Suez Canal. The species apparently invaded the western Atlantic Ocean in the late 1980s. It was first discovered on the north coast of Cuba in 1987 and has since been found off the coasts of Colombia and Venezuela. Adults prefer soft substrates but are also found on rocky bottom and among living coral.
Males can be twelve centimeters wide across the back.
Females can carry between 22,000 and 292,000 eggs. The larvae have never been described. However, similar species of Charybdis have 5-6 planktonic zoeal stages and one postlarval stage. Stomach fullness and the relative presence of animal prey in the contents were significantly higher in crabs collected at sunset than in those caught at dawn. These pages are far from being complete.