An extreme ocean heat wave did something remarkable to these fish
Those measurements revealed something peculiar: Most of the fish shrank.
This week, the researchers reported their findings in Science Advances, concluding that the fish got shorter — on the scale of a few millimeters, or a small, single-digit percent of their length — in response to the heat wave.
'We were so surprised to see shrinking in these fish that, to be sure, we measured each fish individual repeatedly over a period of five months,' said Melissa Versteeg, a doctoral researcher at Newcastle University, who led the study in collaboration with Mahonia Na Dari, an environmental organization, and Walindi Resort. 'In the end, we discovered [that downsizing] was very common in this population.'
Versteeg and her colleagues don't know how, exactly, the fish are shrinking — one untested idea is that the fish might be reabsorbing some of their bone material or tissue. But getting smaller isn't a problem. In fact, the study found, it may be an adaptation to help clownfish survive hotter ocean temperatures.
Morgan Bennett-Smith
Last year, the planet was about 2.65 degrees warmer than it was in the late 1800s. This level of warming impacts wild animals in a number of strange, mostly bad, ways, from fueling koala-killing wildfires to causing corals to bleach and then starve.
But rising temperatures also appear to be making many species smaller. One especially striking study, published in 2019, found that birds shrank by an average of about 2.6 percent between 1978 and 2016. More recent analyses have linked rising temperatures to a reduction in body size of small mammals in North America and marine fish. Most of these existing studies report that animals, on average, are simply not growing as large.
The new study on clownfish, however, suggests individual fish are shrinking over mere weeks in response to a heat wave, which, in the case of the Papua New Guinea event, pushed temperatures in the bay about 7 degrees (4 degrees Celsius) above average.
Being tiny has its advantages in a hot climate: Warm-blooded animals, like mammals, shed heat more easily when they're small and this helps them cool down. The benefits for cold-blooded creatures, such as clownfish, aren't as clear, though researchers think they may have an easier time meeting their bodies' energy requirements when they're small.
Morgan Bennett-Smith
Regardless of the reason, being small seems to help clownfish when it's hot. The fish that shrank, the study found, had a much higher chance of surviving.
'It was a surprise to see how rapidly clownfish can adapt to a changing environment,' Versteeg said. 'We witnessed how flexibly they regulated their size, as individuals and as breeding pairs, in response to heat stress as a successful technique to help them survive.'
The study adds a layer of complexity to what is otherwise a depressing tale about the world's oceans. Heat waves linked to climate change, like the one that occurred during this study, are utterly devastating coral reefs — and in severe cases, are nearly wiping out entire reef sections. These colorful ecosystems are home to countless marine animals, including those we eat, like snappers, and clownfish.
Amid that loss, animals are proving highly resilient. They're trying hard to hold on. Yet if warming continues, even the best adaptations may not be enough.
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11 hours ago
- CNN
Fossils unearthed in Grand Canyon reveal new details of evolutionary explosion of life
Paleontologists have discovered remarkable fossils in the Grand Canyon that reveal fresh details about the emergence of complex life half a billion years ago. The newfound remains of fauna from the region suggest that it offered ideal conditions for life to flourish and diversify, in a 'Goldilocks zone' between harsh extremes elsewhere. This evolutionary opportunity produced a multitude of early animals, including oddballs with peculiar adaptations for survival, according to new research. During the Cambrian explosion, which played out in the coastal waters of Earth's oceans about 540 million years ago, most animal body types that exist today emerged in a relatively short time span, scientists believe. Back then, the Grand Canyon was closer to the equator, and the region was covered by a warm, shallow sea teeming with burgeoning life — aquatic creatures resembling modern-day shrimp, pill bugs and slugs — all developing new ways to exploit the abundant resources. Researchers turned to the Grand Canyon's layers of sedimentary rock to unlock secrets of this pivotal moment in the history of life, digging into the flaky, claylike shale of the Bright Angel Formation where most of the canyon's Cambrian-era fossils have been found. The study team expected to recover mostly the fossilized remains of hard-shelled invertebrates typical of the region. Instead, the team unearthed something unusual: rocks containing well-preserved internal fragments of tiny soft-bodied mollusks, crustaceans, and priapulids, also known as penis worms. 'With these kinds of fossils, we can better study their morphology, their appearance, and their lifestyle in much greater resolution, which is not possible with the shelly parts,' said Giovanni Mussini, the first author of the study published Wednesday in the journal Science Advances. 'It's a new kind of window on Cambrian life in the Grand Canyon.' Using high-powered microscopes, the team was able to investigate innovations such as miniature chains of teeth from rock-scraping mollusks and the hairy limbs and molars of filter-feeding crustaceans, providing a rare look into the biologically complex ways Cambrian animals adapted to capture and eat prey. For most of the planet's 4 billion-year history, simplicity reigned. Single-celled microbes remained stationary on the ocean floor, thriving on chemical compounds such as carbon dioxide and sulfur molecules to break down food. What changed? Scientists still debate what drove the Cambrian explosion, but the most popular theory is that oxygen in the Earth's atmosphere slowly began to increase about 550 million years ago, said Erik Sperling, an associate professor of Earth and planetary sciences at Stanford University. Oxygen provided a much more efficient way to metabolize food, giving animals more energy to mobilize and hunt for prey, suggested Sperling, who was not involved in the new study. 'The (emergence of) predators kicked off these escalatory arms races, and then we basically got the explosion of different ways of doing business,' Sperling said. During the Cambrian, the shallow sea covering the Grand Canyon was especially oxygen-rich thanks to its perfect, 'Goldilocks' depth, said Mussini, a doctoral student in Earth sciences at the University of Cambridge in the United Kingdom. Ranging from 40 to 50 meters (about 130 to 165 feet) in depth, the ecosystem was undisturbed by the shoreline's constant waves shifting around sediments, and sunlight was still able to reach photosynthesizing plants on the seafloor that could provide oxygen. The abundance of food and favorable environmental conditions meant that animals could take more evolutionary risks to stay ahead of their competition, Mussini said. 'In a more resource-starved environment, animals can't afford to make that sort of physiological investment,' Mussini said in a news release from the University of Cambridge. 'It's got certain parallels with economics: invest and take risks in times of abundance; save and be conservative in times of scarcity.' Many soft-bodied fossil finds before this one have come from regions with harsh environments such as Canada's Burgess Shale formation and China's Maotianshan Shales, noted Susannah Porter, a professor of Earth science at the University of California in Santa Barbara who was not involved in the study. 'It's not unlike if paleontologists far in the future only had great fossil records from Antarctica, where harsh cold environments forced people to adapt. … But then found great human fossils in New York City, where people flourished,' Porter explained. 'We have an opportunity to see different sorts of evolutionary pressures that aren't like, it's really cold, it's really hot, there's not a lot of water.' While some of the feeding mechanisms uncovered in the Grand Canyon fossils are still around today, others are much more alien. Among the most freakish: penis worms that turned their mouths inside out, revealing a throat lined with hairy teeth. The worms, also known as cactus worms, are mostly extinct today, but were widespread during the Cambrian. The fossilized worm found in the Grand Canyon represents a previously unknown species. Due to its relatively large size — about 3.9 inches (10 centimeters) — and distinct teeth, it was named Kraytdraco spectatus, after the fictional krayt dragon from the Star Wars universe, Mussini said. This particular penis worm appears to have had a gradient of hundreds of branching teeth used to sweep food into their extendable mouths. 'It's a bit hard to understand how exactly it was feeding,' Mussini said. 'But it was probably eating debris on the seafloor, scraping it away with some of the most robust teeth that it had, and then using these other, more delicate teeth to filter and retain it within this long, tube-like mouth.' Rows of tiny molars, sternal parts and comblike limbs that once belonged to crustaceans were also among the findings, which all date back 507 million to 502 million years. Similar to today's brine shrimp, the crustaceans used these fine-haired limbs to capture floating food from the water and bring it to the mouth, where molars would then grind down the particles, Mussini explained. Nestled among the molars, researchers even found a few unlucky plankton. Other creatures resembling their modern counterparts included sluglike mollusks. The fossils revealed chains of teeth that likely helped them scrape algae or bacteria from along the seafloor. 'For each of these animals, there's different components, but most of what we found directly relates to the way these animals were processing their food, which is one of the most exciting parts, because it tells us a lot about their lifestyle, and as a consequence, their ecological implications,' Mussini said. Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
CNN
11 hours ago
- CNN
Evolution ran wild 500 million years ago in the friendly waters of the Grand Canyon, study suggests
Ancient creatures Animal storiesFacebookTweetLink Paleontologists have discovered remarkable fossils in the Grand Canyon that reveal fresh details about the emergence of complex life half a billion years ago. The newfound remains of fauna from the region suggest that it offered ideal conditions for life to flourish and diversify, in a 'Goldilocks zone' between harsh extremes elsewhere. This evolutionary opportunity produced a multitude of early animals, including oddballs with peculiar adaptations for survival, according to new research. During the Cambrian explosion, which played out in the coastal waters of Earth's oceans about 540 million years ago, most animal body types that exist today emerged in a relatively short time span, scientists believe. Back then, the Grand Canyon was closer to the equator, and the region was covered by a warm, shallow sea teeming with burgeoning life — aquatic creatures resembling modern-day shrimp, pill bugs and slugs — all developing new ways to exploit the abundant resources. Researchers turned to the Grand Canyon's layers of sedimentary rock to unlock secrets of this pivotal moment in the history of life, digging into the flaky, claylike shale of the Bright Angel Formation where most of the canyon's Cambrian-era fossils have been found. The study team expected to recover mostly the fossilized remains of hard-shelled invertebrates typical of the region. Instead, the team unearthed something unusual: rocks containing well-preserved internal fragments of tiny soft-bodied mollusks, crustaceans, and priapulids, also known as penis worms. 'With these kinds of fossils, we can better study their morphology, their appearance, and their lifestyle in much greater resolution, which is not possible with the shelly parts,' said Giovanni Mussini, the first author of the study published Wednesday in the journal Science Advances. 'It's a new kind of window on Cambrian life in the Grand Canyon.' Using high-powered microscopes, the team was able to investigate innovations such as miniature chains of teeth from rock-scraping mollusks and the hairy limbs and molars of filter-feeding crustaceans, providing a rare look into the biologically complex ways Cambrian animals adapted to capture and eat prey. For most of the planet's 4 billion-year history, simplicity reigned. Single-celled microbes remained stationary on the ocean floor, thriving on chemical compounds such as carbon dioxide and sulfur molecules to break down food. What changed? Scientists still debate what drove the Cambrian explosion, but the most popular theory is that oxygen in the Earth's atmosphere slowly began to increase about 550 million years ago, said Erik Sperling, an associate professor of Earth and planetary sciences at Stanford University. Oxygen provided a much more efficient way to metabolize food, giving animals more energy to mobilize and hunt for prey, suggested Sperling, who was not involved in the new study. 'The (emergence of) predators kicked off these escalatory arms races, and then we basically got the explosion of different ways of doing business,' Sperling said. During the Cambrian, the shallow sea covering the Grand Canyon was especially oxygen-rich thanks to its perfect, 'Goldilocks' depth, said Mussini, a doctoral student in Earth sciences at the University of Cambridge in the United Kingdom. Ranging from 40 to 50 meters (about 130 to 165 feet) in depth, the ecosystem was undisturbed by the shoreline's constant waves shifting around sediments, and sunlight was still able to reach photosynthesizing plants on the seafloor that could provide oxygen. The abundance of food and favorable environmental conditions meant that animals could take more evolutionary risks to stay ahead of their competition, Mussini said. 'In a more resource-starved environment, animals can't afford to make that sort of physiological investment,' Mussini said in a news release from the University of Cambridge. 'It's got certain parallels with economics: invest and take risks in times of abundance; save and be conservative in times of scarcity.' Many soft-bodied fossil finds before this one have come from regions with harsh environments such as Canada's Burgess Shale formation and China's Maotianshan Shales, noted Susannah Porter, a professor of Earth science at the University of California in Santa Barbara who was not involved in the study. 'It's not unlike if paleontologists far in the future only had great fossil records from Antarctica, where harsh cold environments forced people to adapt. … But then found great human fossils in New York City, where people flourished,' Porter explained. 'We have an opportunity to see different sorts of evolutionary pressures that aren't like, it's really cold, it's really hot, there's not a lot of water.' While some of the feeding mechanisms uncovered in the Grand Canyon fossils are still around today, others are much more alien. Among the most freakish: penis worms that turned their mouths inside out, revealing a throat lined with hairy teeth. The worms, also known as cactus worms, are mostly extinct today, but were widespread during the Cambrian. The fossilized worm found in the Grand Canyon represents a previously unknown species. Due to its relatively large size — about 3.9 inches (10 centimeters) — and distinct teeth, it was named Kraytdraco spectatus, after the fictional krayt dragon from the Star Wars universe, Mussini said. This particular penis worm appears to have had a gradient of hundreds of branching teeth used to sweep food into their extendable mouths. 'It's a bit hard to understand how exactly it was feeding,' Mussini said. 'But it was probably eating debris on the seafloor, scraping it away with some of the most robust teeth that it had, and then using these other, more delicate teeth to filter and retain it within this long, tube-like mouth.' Rows of tiny molars, sternal parts and comblike limbs that once belonged to crustaceans were also among the findings, which all date back 507 million to 502 million years. Similar to today's brine shrimp, the crustaceans used these fine-haired limbs to capture floating food from the water and bring it to the mouth, where molars would then grind down the particles, Mussini explained. Nestled among the molars, researchers even found a few unlucky plankton. Other creatures resembling their modern counterparts included sluglike mollusks. The fossils revealed chains of teeth that likely helped them scrape algae or bacteria from along the seafloor. 'For each of these animals, there's different components, but most of what we found directly relates to the way these animals were processing their food, which is one of the most exciting parts, because it tells us a lot about their lifestyle, and as a consequence, their ecological implications,' Mussini said. Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
CNN
11 hours ago
- CNN
Evolution ran wild 500 million years ago in the friendly waters of the Grand Canyon, study suggests
Paleontologists have discovered remarkable fossils in the Grand Canyon that reveal fresh details about the emergence of complex life half a billion years ago. The newfound remains of fauna from the region suggest that it offered ideal conditions for life to flourish and diversify, in a 'Goldilocks zone' between harsh extremes elsewhere. This evolutionary opportunity produced a multitude of early animals, including oddballs with peculiar adaptations for survival, according to new research. During the Cambrian explosion, which played out in the coastal waters of Earth's oceans about 540 million years ago, most animal body types that exist today emerged in a relatively short time span, scientists believe. Back then, the Grand Canyon was closer to the equator, and the region was covered by a warm, shallow sea teeming with burgeoning life — aquatic creatures resembling modern-day shrimp, pill bugs and slugs — all developing new ways to exploit the abundant resources. Researchers turned to the Grand Canyon's layers of sedimentary rock to unlock secrets of this pivotal moment in the history of life, digging into the flaky, claylike shale of the Bright Angel Formation where most of the canyon's Cambrian-era fossils have been found. The study team expected to recover mostly the fossilized remains of hard-shelled invertebrates typical of the region. Instead, the team unearthed something unusual: rocks containing well-preserved internal fragments of tiny soft-bodied mollusks, crustaceans, and priapulids, also known as penis worms. 'With these kinds of fossils, we can better study their morphology, their appearance, and their lifestyle in much greater resolution, which is not possible with the shelly parts,' said Giovanni Mussini, the first author of the study published Wednesday in the journal Science Advances. 'It's a new kind of window on Cambrian life in the Grand Canyon.' Using high-powered microscopes, the team was able to investigate innovations such as miniature chains of teeth from rock-scraping mollusks and the hairy limbs and molars of filter-feeding crustaceans, providing a rare look into the biologically complex ways Cambrian animals adapted to capture and eat prey. For most of the planet's 4 billion-year history, simplicity reigned. Single-celled microbes remained stationary on the ocean floor, thriving on chemical compounds such as carbon dioxide and sulfur molecules to break down food. What changed? Scientists still debate what drove the Cambrian explosion, but the most popular theory is that oxygen in the Earth's atmosphere slowly began to increase about 550 million years ago, said Erik Sperling, an associate professor of Earth and planetary sciences at Stanford University. Oxygen provided a much more efficient way to metabolize food, giving animals more energy to mobilize and hunt for prey, suggested Sperling, who was not involved in the new study. 'The (emergence of) predators kicked off these escalatory arms races, and then we basically got the explosion of different ways of doing business,' Sperling said. During the Cambrian, the shallow sea covering the Grand Canyon was especially oxygen-rich thanks to its perfect, 'Goldilocks' depth, said Mussini, a doctoral student in Earth sciences at the University of Cambridge in the United Kingdom. Ranging from 40 to 50 meters (about 130 to 165 feet) in depth, the ecosystem was undisturbed by the shoreline's constant waves shifting around sediments, and sunlight was still able to reach photosynthesizing plants on the seafloor that could provide oxygen. The abundance of food and favorable environmental conditions meant that animals could take more evolutionary risks to stay ahead of their competition, Mussini said. 'In a more resource-starved environment, animals can't afford to make that sort of physiological investment,' Mussini said in a news release from the University of Cambridge. 'It's got certain parallels with economics: invest and take risks in times of abundance; save and be conservative in times of scarcity.' Many soft-bodied fossil finds before this one have come from regions with harsh environments such as Canada's Burgess Shale formation and China's Maotianshan Shales, noted Susannah Porter, a professor of Earth science at the University of California in Santa Barbara who was not involved in the study. 'It's not unlike if paleontologists far in the future only had great fossil records from Antarctica, where harsh cold environments forced people to adapt. … But then found great human fossils in New York City, where people flourished,' Porter explained. 'We have an opportunity to see different sorts of evolutionary pressures that aren't like, it's really cold, it's really hot, there's not a lot of water.' While some of the feeding mechanisms uncovered in the Grand Canyon fossils are still around today, others are much more alien. Among the most freakish: penis worms that turned their mouths inside out, revealing a throat lined with hairy teeth. The worms, also known as cactus worms, are mostly extinct today, but were widespread during the Cambrian. The fossilized worm found in the Grand Canyon represents a previously unknown species. Due to its relatively large size — about 3.9 inches (10 centimeters) — and distinct teeth, it was named Kraytdraco spectatus, after the fictional krayt dragon from the Star Wars universe, Mussini said. This particular penis worm appears to have had a gradient of hundreds of branching teeth used to sweep food into their extendable mouths. 'It's a bit hard to understand how exactly it was feeding,' Mussini said. 'But it was probably eating debris on the seafloor, scraping it away with some of the most robust teeth that it had, and then using these other, more delicate teeth to filter and retain it within this long, tube-like mouth.' Rows of tiny molars, sternal parts and comblike limbs that once belonged to crustaceans were also among the findings, which all date back 507 million to 502 million years. Similar to today's brine shrimp, the crustaceans used these fine-haired limbs to capture floating food from the water and bring it to the mouth, where molars would then grind down the particles, Mussini explained. Nestled among the molars, researchers even found a few unlucky plankton. Other creatures resembling their modern counterparts included sluglike mollusks. The fossils revealed chains of teeth that likely helped them scrape algae or bacteria from along the seafloor. 'For each of these animals, there's different components, but most of what we found directly relates to the way these animals were processing their food, which is one of the most exciting parts, because it tells us a lot about their lifestyle, and as a consequence, their ecological implications,' Mussini said. Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
