🏄♂️ Da Hammerhead Sharks Get Cool Trick Fo’ Stay Warm 🔥🦈
Da deep-diving hammerhead sharks get one crazy kine way fo’ stay warm wen dey look fo’ food in da icy ocean. Dey use one trick neva seen in odda fish befo’. Dem hammerhead sharks, dey like da warm watah, but fo’ one ono grindz, dey no mind get cold. Da flat-head kine predators dive ova 2,600 feet from da tropical surface watah down to da ocean’s cold deep fo’ catch fish an’ squid, putting up wit’ 68 degrees Fahrenheit drop in temperature fo’ one good kaukau. 🌊🦑
So how dese coldblooded chondrichthyans stay warm wit’out turnin’ into frozen fish? One study published in da journal Science talk about how one species, da Sphyrna lewini, o’ scalloped hammerhead sharks, keep warm wen dey dive at nite: Dey no need da frills an’ dey close dea gills, sorta like holdin’ dea breath. 😲🌬️
Dis kine strategy fo’ keepin’ one coldblooded fish warm neva been seen befo’, an’ make dem different from da high-performance fish (yup, das da scientific term) like da great white sharks o’ Atlantic bluefin tuna dat use way different ways fo’ handle da extreme cold. ❄️🐟
Mark Royer, one shark biologist at da University of Hawaiʻi at Mānoa, wen get da idea fo’ check out da scalloped hammerhead’s secret heating technique afta he wen notice how deep dey been diving wen he was doing odda research. He wen put one package wit’ sensors near da dorsal fins of six hammerheads by Hawai’i. Da packages wen come off da sharks afta few weeks an’ den send one satellite signal wen time fo’ scoop ’em out da ocean. 🌴🦈
Da tags, Dr. Royer said, was like shark Fitbits, collecting data like depth an’ body temperature. Dey was sensitive enough fo’ catch each small kine flick of da fish’s tail. Dr. Royer an’ his friends wen find out dat da hammerheads lose lil bit body heat wen dey start going down, but den fast kine come back to da same temperature as da surface wen dey swim deepa. Even wen da watah was 39 degrees Fahrenheit, da sharks had body temp around 75 degrees during one hour long dives. ⌚🌡️
Sharks stay ectotherms, dat means dea body temp stay mostly da same as da watah temp around ’em. Dr. Royer an’ his crew wen use one mathematical model fo’ show dat da temperature data dey collected no make sense unless da sharks was somehow keeping dea body heat. Dey also wen check da heat exchange between some dead scalloped hammerheads (dat wen wash up on da beach) an’ one watah bath an’ found out da rates stay da same as da live deep-diving sharks an’ ocean watah. Da main similarity between da two? “No conductive heat loss across da gills,” Dr. Royer wen say. An’ da gills stay da numba one place fo’ heat loss in one fish body. 🌡️🐠
“Gills stay like big kine radiators strapped to da head,” he wen say.
Da conserved body heat an
‘ da lack of odda physical changes dat could stop heat loss convinced Dr. Royer dat da fish was “holding dea breath,” somehow stopping da watah flowing ova dea gills — an’ dea ability fo’ take in oxygen. Da scientists think da hammerheads do dis by closing da gill slits physically, based on one 2015 observation of one scalloped hammerhead doing so more than 3,000 feet unda da surface. Dr. Royer like attach video cameras to diving hammerheads next fo’ confirm dis theory. 🎥🔍
Catherine Macdonald, one marine biologist at da University of Miami who neva have anything fo’ do wit’ da study, agreed wit’ da team’s reasoning, saying dat she couldn’t “see a way” da sharks could be breathing normally while keeping da body temperatures seen in da data. 🌊🔬
Dr. Royer planning next fo’ study da hammerheads’ metabolism fo’ understand betta da recovery time afta da extreme physical feat dey perform each night. He tink dat da hammerheads’ like fo’ short periods of high activity might explain why dey die so easy wen trapped on fishing lines fo’ many hours; it’s like asking one elite sprinter fo’ run one marathon. 🏃♂️🎣
“Dis study invites plenty mo’ studies,” Dr. Macdonald wen say. “I stay always surprised by sharks’ ability fo’ surprise me.” So, da next time you tinking ’bout da sharks, rememba dat dey get plenny surprises up dea sleeves, or should I say, up dea fins. 🦈🤯🤙
NOW IN ENGLISH
🏄♂️ Hammerhead Sharks Have a Cool Trick to Stay Warm 🔥🦈
Deep-diving hammerhead sharks have an amazing way to stay warm when they search for food in the icy ocean. They use a trick never seen in other fish before. These hammerhead sharks, they prefer the warm water, but for a delicious meal, they don’t mind getting cold. These flat-headed predators dive over 2,600 feet from the tropical surface water down to the ocean’s cold depths to catch fish and squid, enduring a 68-degree Fahrenheit drop in temperature for a good meal. 🌊🦑
So how do these cold-blooded chondrichthyans stay warm without turning into frozen fish? A study published in the journal Science discusses how one species, the Sphyrna lewini, or scalloped hammerhead sharks, stay warm when they dive at night: They don’t need the frills and they close their gills, sort of like holding their breath. 😲🌬️
This kind of strategy for keeping a cold-blooded fish warm has never been seen before, and it sets them apart from the high-performance fish (yes, that’s the scientific term) like great white sharks or Atlantic bluefin tuna that use very different methods to handle the extreme cold. ❄️🐟
Mark Royer, a shark biologist at the University of Hawaiʻi at Mānoa, got the idea to investigate the scalloped hammerhead’s secret heating technique after he noticed how deep they were diving when he was doing other research. He put a package with sensors near the dorsal fins of six hammerheads in Hawaii. The packages came off the sharks after a few weeks and then sent a satellite signal when it was time to scoop them out of the ocean. 🌴🦈
The tags, Dr. Royer said, were like shark Fitbits, collecting data like depth and body temperature. They were sensitive enough to detect each slight flick of the fish’s tail. Dr. Royer and his colleagues found out that the hammerheads lose a little bit of body heat when they start going down, but then quickly return to the same temperature as the surface when they swim deeper. Even when the water was 39 degrees Fahrenheit, the sharks had body temperatures around 75 degrees during one-hour-long dives. ⌚🌡️
Sharks are ectotherms, which means their body temperature stays mostly the same as the water temperature around them. Dr. Royer and his team used a mathematical model to show that the temperature data they collected didn’t make sense unless the sharks were somehow conserving their body heat. They also checked the heat exchange between some dead scalloped hammerheads (that had washed up on the beach) and a water bath and found out the rates were the same as the live deep-diving sharks and ocean water. The main similarity between the two? “No conductive heat loss across the gills,” Dr. Royer said. And the gills are the number one place for heat loss in a fish’s body. 🌡️🐠
“Gills are like big radiators strapped to the head,” he said.
The conserved body heat and the lack of other physical changes that could prevent heat loss convinced Dr. Royer that the fish were “holding their breath,” somehow stopping the water flowing over their gills — and their ability to take in oxygen. The scientists think the hammerheads do this by physically closing the gill slits, based on a 2015 observation of a scalloped hammerhead doing so more than 3,000 feet under the surface. Dr. Royer wants to attach video cameras to diving hammerheads next to confirm this theory. 🎥🔍
Catherine Macdonald, a marine biologist at the University of Miami who was not involved with the study, agreed with the team’s reasoning, saying that she couldn’t “see a way” the sharks could be breathing normally while maintaining the body temperatures seen in the data. 🌊🔬
Dr. Royer is next planning to study the hammerheads’ metabolism to better understand the recovery period that follows the extreme athletic feat they perform each night. He suspects that the hammerheads’ preference for relatively short periods of high activity may explain why they die so easily when trapped on fishing lines for many hours; it’s like asking an elite sprinter to run a marathon. 🏃♂️🎣
“This study invites a lot of additional studies,” Dr. Macdonald said. “I am always surprised by sharks’ ability to surprise me.” So, the next time you’re thinking about sharks, remember that they have plenty of surprises up their sleeves, or should I say, up their fins. 🦈🤯🤙
