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).
shalamov/iStock/Getty Images. The two species of manta rays are the worldâs biggest rays: The giant oceanic manta, at its heftiest, may reach 7 meters (23 feet) from wingtip to wingtip and weigh about 2 tonnes (4,440 pounds), and the reef manta isnât much smaller.