The movement of the hard drive's read/write heads over different areas of the disk when accessing fragmented files is slower, compared to accessing the entire contents of a non-fragmented file sequentially without moving the read/write heads to seek other fragments.
The dorsal fins are small and at the base of the tail. The largest mantas can reach 1,350 kg (2,980 lb). In both species the width is approximately 2.2 times the length of the body; M. birostris reaches at least 7 m (23 ft) in width while M. alfredi reaches about 5.5 m (18 ft).
As of 2009, the baby ray in the study had grown to more than 286 pounds (130 kilograms) and had a wingspan of almost 7 feet (2.1 meters). Manta rays (Manta alfredi) live in tropical and subtropical waters around the world.