Though often intend of as nature ’s gross swim machines , not all sharks are optimally designed to glide straight through the piss . accord to a new sketch appearing in the journalNature Communications , hammerhead sharks are really better at swim on their side than upright , and therefore keep their bodies wring in this unnatural position around 90 pct of the meter .
As unknown as it may sound , almost all shark arenegatively buoyant – meaning they settle rather than blow . To stop themselves from fetch a mouthful of seabed , they apply their pectoral fin to render vertical hydrodynamic force that countermine gravity , much like thewings of an airplane . The dorsal fin , meanwhile , is used to steer and change direction , like the rudder of a boat .
Hammerheadsin finicky haveextremely powerful dorsal fins , which give them an advantage when track down prey by enabling them to twist and turn at outstanding speed . However , it sprain out that this enlarged dorsal fin is also perfect for generating lift , which is why the sharks spend most of their clock time swimming on their side in what the study authors call a “ vagabond ” stead .
The tagged shark expend most of their sentence swimming in a " rolled " billet , with the optimum slant for swim being between 50 and 70 degree . Nicholas L. Payne et al / Nature Communications
The researchers find this by tagging two numskull sharks – one in Australia ’s Great Barrier Reef and one in Belize . Using cameras and accelerometer lumberman , they calculated that the Australian shark drop 90 percent of its time swimming at a roller angle of between 50 and 75 degrees , while the other uphold a body position of 30 to 80 degrees .
To figure out why the shark do this , the squad then carried out a serial of experiments in a wind tunnel using a scale model of a dumbass . Their results showed that swim at a roll slant of between 50 and 70 degree come down drag by around 10 percent , indicate that this is the good swimming position for hammerheads as it requires the least amount of effort .
All in all , the researchers suggest that not only does obliquely swimming make sense for sharks , but it could also bring home the bacon a solution for mechanically skillful engineers seeking new ways to reduce drag and increase lift – though it could make walking up and down the aisle of a plane a lilliputian tricky .
