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).
Since the Manta Ray seems to be such a mystery to most people, exploring the facts about them can help you to see them for what they really are. These are fascinating creatures that live in the water. They can be up to 25 feet in length and weight as much as 3,000 pounds. Manta birostris (Giant Manta Ray) engage in the process of migrating. They can lose their protective mucus membrane if they are touched by humans. The Manta Ray has the largest brain to body ratio of all sharks and rays on Earth. You will very rarely find any Manta Ray in captivity due to their size. They are currently only found in four aquariums in the world. The average life span for a Manta Ray is 20 years. They are very close relatives of the shark.