Sharks have spiral-shaped intestines that work in an identical approach to an uncommon valve designed by Nikola Tesla. Learning their anatomy may assist enhance industrial fluid-pump expertise.
Most animals have tubular intestines that use muscle contractions to push meals alongside like squeezing a tube of toothpaste. However sharks slowly channel their meals by spirals without having muscle mass to push the meals. Their intestines are additionally formed in a method that solely permits meals to move a technique – like a performance-enhanced Tesla valve, says Samantha Leigh at California State College Dominguez Hills.
“Sharks have all these completely different little tweaks to the Tesla valve design that may very well be making them extra environment friendly,” she says.
Leigh and her colleagues surgically eliminated the whole digestive tubes from 32 lifeless sharks that had both been donated to their venture or conserved within the Pure Historical past Museum of Los Angeles County, representing 22 shark households. Every has one in every of 4 completely different sorts of spiral gut: columnar, which seems to be like a spiral staircase; scroll, which seems to be like a rolled-up sheet of paper; and two sorts with both upward-facing or downward-facing funnels.
The researchers stuffed all of the intestines with fluid and freeze-dried them to maintain their pure form earlier than scanning them utilizing computed tomography. From these scans, they created digital 3D fashions, providing the primary glimpse of how these “pure” Tesla valves are structured and performance, says Leigh.
Then, utilizing an unfrozen pattern of every of the 4 sorts of gut, the researchers discovered that liquids took about 35 minutes to run by the spirals within the regular route of move. Nonetheless, once they turned the spiral intestines the wrong way up – reverse the traditional move – liquids took as much as twice as lengthy to cross by the 2 funnel sorts as they did beforehand.
The crew additionally examined spiral gut perform in 5 not too long ago euthanised Pacific spiny dogfish sharks (Squalus suckleyi) by operating colored liquids of assorted thicknesses by the spirals. As a result of the sharks had simply died, their spiral muscle mass nonetheless reacted to the presence of the liquid. The researchers decided that these contractions “combine and churn” fluids versus pushing them alongside, says Leigh. “Simply the construction of the gut itself will do this work of shifting issues alongside unidirectionally.”
Shark-inspired expertise may very well be particularly helpful for industries requiring move shifting in a single route with minimal power use, like filtering microplastics from waste water, she says.
Whereas scientists nonetheless don’t know why sharks have these particular intestines, they believe they could extract the utmost quantity of vitamins from meals, serving to them survive for weeks with out a meal, says Leigh.
Journal reference: Proceedings of the Royal Society B, DOI: 10.1098/rspb.2021.1359
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