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).
In general, every member of the genus Manta has a large and flattened body whose center is called âdiscoâ. The reef manta ray disc has a width of 3 to 3.5 meters, while the giant manta ray lives up to its name measuring up to 9 meters wide. The head of both species is wide, eyes on each side and the long nose in front.