Tag Archives: Fish

Fossil Discovery Sheds Light on the Origins of Earth’s First Fish

Posted on by
Reply

Paleontologists from Australia and China have conducted two groundbreaking studies on the fossilized remains of a remarkable Devonian lungfish. Utilizing advanced imaging technology, they have unearthed previously overlooked anatomical details, significantly enhancing our understanding of early vertebrate evolution. Their findings have been published in the Canadian Journal of Zoology and the journal Current Biology.

Paleolophus yunnanensis, a unique lungfish species that thrived in southern China’s waters 410 million years ago. Image credit: Brian Choo, Flinders University.

In a recent study, lead researcher Alice Clement, a paleontologist at Flinders University, investigates The Mystery of Kainokara, a fossil known from a single specimen found in the Late Devonian Gogo Formation of Western Australia.

“New research, including the analysis of previously neglected specimens, is gradually uncovering the rich diversity of lungfishes found in Australia’s significant fossil sites,” said Dr. Clement.

“One particularly enigmatic specimen originates from Australia’s earliest ‘Great Barrier Reef’, a Devonian reef located in the Kimberley region of northern Western Australia.”

“When first described in 2010, this unusual specimen was so perplexing that the authors speculated it might represent an entirely new type of fish never documented in science.”

“Using advanced scanning techniques, we developed comprehensive digital images of both the external and internal structures of the skull, revealing the complexity of this fascinating lungfish’s brain cavity.”

“In fact, we confirmed that earlier interpretations may have been from an upside-down perspective.”

“We were also able to compare the well-preserved inner ear region with other lungfishes,” noted Flinders University paleontologist Hannah Thiele.

“This provides an essential data point in the rich collection of lungfish and early vertebrate species.”

“This research enhances our understanding of the evolutionary progression of these ancient lobe-finned fishes, both in Gondwana and globally.”

In a separate study, Flinders University paleontologist Brian Chu and colleagues reveal a newly discovered species of lungfish from the Devonian period in China, Paleolophus yunanensis.

“The discovery of Paleolophus yunanensis offers unprecedented insight into the transitional phase between the early appearance of lungfish and their extensive diversification millions of years later,” said Dr. Chu.

“At this time, this group was just beginning to develop unique feeding adaptations that would serve them well throughout the remainder of the Devonian period and into the present.”

“Lungfish, including the ancient lineage found in Queensland, Australia, have fascinated researchers due to their close evolutionary relationship with tetrapods, the four-limbed vertebrates that include humans.”

“The distinctive skull of the newly discovered lungfish from 410-million-year-old rock formations in Yunnan offers crucial insights into the rapid evolutionary changes during the Early, Middle, and Late Devonian periods.”

“The new specimens exhibited both similarities and differences compared to the earliest known specimens, such as Diabolepis fossils from southern China and uranolophus found in locations like Wyoming and Australia.

_____

Hannah S. Thiele et al., deciphering The Mystery of Kainokara from the Late Devonian Gogo Formation, Australia. Canadian Journal of Zoology, published online January 28, 2026. doi: 10.1139/cjz-2025-0109

Tuo Qiao et al., 2026. New fish fossil sheds light on the rapid evolution of early lungfish. Current Biology 36 (1): 243-251; doi: 10.1016/j.cub.2025.11.032

Source: www.sci.news

Scientists Uncover Unique Internal Drum Structure in Odd-Looking Fish

Posted on by
Reply

The Armored Rockhead Poacher (Boslagonus Swanee) possesses a mysterious anatomical feature: a bowl-shaped cavity in its skull that has puzzled marine biologists for years. This unique trait is now believed to play a critical role in an innovative form of communication.

The Rockhead Poacher (Boslagonus Swanee) at the Oregon Coast Aquarium. Image credit: Rhinopias / CC BY-SA 4.0.

Originally described by Franz Steindachner in 1876, Boslagonus Swanee belongs to the family Agonidae. This fascinating fish can be found at depths of up to 18 meters in the eastern Pacific Ocean, from Alaska down to Carmel Bay in California.

Marine experts have long speculated about the purpose of the cavernous cranial fossa, which is roughly the size of the fish’s brain. Some theories suggest it aids in camouflage among rocky environments, while others propose it enhances hearing and sensory perception.

Recent advancements in imaging technology have led Louisiana State University student Daniel Geldof to propose a groundbreaking explanation. His findings suggest it might resonate with the rhythm of rock music rather than the serenity of coral reefs.

“My dissertation project aims to uncover the reasons behind this unique feature,” Geldof explained.

Utilizing a high-resolution micro-CT scanner, his team created an intricate 3D model of the rockhead poacher’s anatomy.

These scans indicated that the fish’s initial set of ribs are notably large, flat, and free-moving, positioned near the epigastric region of the skull without direct attachment.

Located at the base of these ribs are powerful muscles and tendons resembling drumsticks.

When these ribs vibrate against the skull’s calcified cavities, they create pulses of sound that can be transmitted through the substrate.

Geldof posits that this percussive mechanism likely evolved to facilitate communication among fish in their acoustically challenging intertidal habitats, where traditional underwater communication might be hindered by crashing waves and background noise.

In this rugged, shallow environment, using substrate vibrations may provide a more efficient means of communication aligned with the fish’s unique lifestyle.

Furthermore, Professor Geldof’s research combined contrast-enhanced soft tissue scans with data on bone structures to map the nerves, muscles, and microstructures within rockhead poachers, suggesting that the cranial fossa may serve sensory functions as well.

Branches of the dorsal lateral line nerve—a crucial component of the fish’s movement-sensing system—extend into the cavity, and the arrangement of microstructures suggests a role in mechanoreception, allowing the fish to sense movement and pressure.

Geldof concludes that this anatomical feature is multifunctional, serving both communicative and sensory purposes within the dynamic intertidal ecosystem.

“The intricate details of this small structure reflect not just a scientific inquiry, but a fundamental human curiosity,” he states.

_____

Daniel L. Geldof 2025. The Truth About Holes: The Morphology of Rockhead Poachers’ Skull Holes, Boslagonus Swanee (Agonidae). LSU Master’s Thesis 6270

Source: www.sci.news

SEO-Optimized Title: “The Late Ordovician Mass Extinction: How It Laid the Foundation for the Evolution of Early Fish”

Posted on by
Reply

A significant enigma in vertebrate evolution—why numerous major fish lineages appeared suddenly in the fossil record tens of millions of years post their presumed origins—has been linked to the Late Ordovician mass extinction (LOME). This insight comes from a recent analysis conducted by paleontologists at the Okinawa Institute of Science and Technology Graduate University. The study reveals that the LOME, occurring approximately 445 to 443 million years ago, instigated a parallel endemic radiation of jawed and jawless vertebrates (gnathostomes) within isolated refugia, ultimately reshaping the early narrative of fishes and their relatives.

Reconstruction of Sacabambaspis jamvieri, an armored jawless fish from the Ordovician period. Image credit: OIST Kaori Seragaki

Most vertebrate lineages initially documented in the mid-Paleozoic emerged significantly after the Cambrian origin and Ordovician invertebrate biodiversity. This temporal gap is often attributed to inadequate sampling and lengthy ghost lineages.

However, paleontologists Kazuhei Hagiwara and Lauren Saran from the Okinawa Institute of Science and Technology Graduate University propose that the LOME may have fundamentally transformed the vertebrate ecosystem.

Utilizing a newly compiled global database of Paleozoic vertebrate occurrences, biogeography, and ecosystems, they identified that this mass extinction coincided with the extinction of stylostome conodonts (extinct marine jawless vertebrates) and the decline of early gnathostomes and pelagic invertebrates.

In the aftermath, the post-extinction ecosystems witnessed the initial definitive emergence of most major vertebrate lineages characteristic of the Paleozoic ‘Age of Fish’.

“While the ultimate cause of LOME remains unclear, clear changes before and after the event are evident through the fossil record,” stated Professor Saran.

“We have assimilated 200 years of Late Ordovician and Early Silurian paleontology and created a novel database of fossil records that will assist in reconstructing the refugia ecosystem,” Dr. Hagiwara elaborated.

“This enables us to quantify genus-level diversity from this era and illustrate how LOME directly contributed to a significant increase in gnathostome biodiversity.”

LOME transpired in two pulses during a period marked by global temperature fluctuations, alterations in ocean chemistry—including essential trace elements—sudden polar glaciation, and fluctuations in sea levels.

These transformations severely impacted marine ecosystems, creating post-extinction ‘gaps’ with reduced biodiversity that extended until the early Silurian period.

The researchers confirmed a previously suggested gap in vertebrate diversity known as the Thalimar gap.

Throughout this time, terrestrial richness remained low, and the surviving fauna consisted largely of isolated microfossils.

The recovery was gradual, with the Silurian period encompassing a 23-million-year recovery phase during which vertebrate lineages diversified intermittently.

Silurian gnathostome lineages displayed gradual diversification during an early phase when global biodiversity was notably low.

Early jawed vertebrates appear to have evolved in isolation rather than rapidly dispersing into ancient oceans.

The researchers noted that gnathostomes exhibited high levels of endemism from the outset of the Silurian period, with diversification occurring primarily in certain long-term extinction reserves.

One such refuge is southern China, where the earliest conclusive evidence of jaws is present in the fossil record.

These primitive jawed vertebrates remained geographically restricted for millions of years.

Turnover and recovery following LOME paralleled climatic fluctuations similar to those at the end of the Devonian mass extinction, including prolonged epochs of low diversity and delayed dominance of jawed fishes.

“For the first time, we discovered the entire body fossil of a jawed fish directly related to modern sharks in what is now southern China,” Dr. Hagiwara noted.

“They remained concentrated in these stable refugia for millions of years until they evolved the capability to migrate across open oceans to new ecosystems.”

“By integrating location, morphology, ecology, and biodiversity, we can finally understand how early vertebrate ecosystems restructured themselves after significant environmental disruptions,” Professor Saran added.

“This study elucidates why jaws evolved, why jawed vertebrates ultimately became widespread, and how modern marine life originated from these survivors rather than earlier forms like conodonts and trilobites.”

For more information, refer to the study published on January 9th in Scientific Progress.

_____

Kazuhei Hagiwara & Lauren Saran. 2026. The mass extinction that initiated the irradiation of jawed vertebrates and their jawless relatives (gnathostomes). Scientific Progress 12(2); doi: 10.1126/sciadv.aeb2297

Source: www.sci.news

Paleontologists Reveal Multiple Instances of Marine Fish Migrating to Freshwater

Posted on by
Reply

The fish supergroup earball, recognized for its superior hearing abilities, includes two-thirds of freshwater fish species. They were previously believed to have originated in freshwater prior to the breakup of the supercontinent Pangaea. This suggests an almost 80 million-year span from their inception to the earliest known fossils. However, the discovery of Acronichthys MacCognoi—a newly identified freshwater ear fish species from the late Cretaceous period—challenges this assumption.

Reconstruction of the Weberian apparatus in Acronichthys MacCognoi. The central golden bone arises from the rib bones (indicated in grey) that connect the fish’s air bladder (left) to the inner ear (right). Image credit: University of California, Berkeley Ken Chronicle.

Underwater ears require a distinct anatomy compared to those that sense airborne sounds.

Many terrestrial vertebrates have evolved eardrum-like structures that vibrate in response to sound waves.

These eardrums amplify sounds, moving bone arrays, similar to the malleus, incus, and stapes found in human middle ears, which then stimulate the fluid-filled inner ear.

In contrast, sound waves travel through fish, which have a density similar to that of the surrounding water.

Consequently, fish have developed an air-filled bladder that vibrates in response to sound passing through it.

These vibrations are then transferred to the fish’s inner ear in a basic manner in most saltwater species.

However, specialized fish have developed bony structures known as “bones” between the air bladder and inner ear (a system called Weberian apparatus), enhancing the amplification and range of frequencies detectable by their ears. For instance, zebrafish can detect frequencies of up to 15,000 Hz, nearing the human limit of 20,000 Hz.

The reason for these fish’s need to hear high frequencies remains unclear, though it may relate to their existence in varied and complex environments, from swift currents to still lakes.

“reason Acronichthys Maccagnoi Professor Neil Banerjee, a researcher at Western University, noted:

“This represents the oldest known North American member of the group and offers invaluable data for documenting the origins and early evolution of numerous freshwater fish species existing today.”

Acronichthys Maccagnoi thrived in the late Cretaceous period roughly 67 million years ago.

The authors utilized microCT scans of 4 cm long fossils to investigate their Weber structure.

They also studied the genomes and morphology of contemporary fish to refine the evolutionary lineage of freshwater species and simulate frequency responses of the middle ear structures of fossil fish.

Their model indicates that even 67 million years ago, Otophysan fish may have possessed hearing sensitivity on par with today’s zebrafish.

“We were uncertain if this constituted a fully functional Weberian device, but the simulation proved effective,” stated Dr. Juan Liu, a paleontologist at the University of California, Berkeley.

“The Weberian apparatus suggests it’s less sensitive than that of zebrafish.”

“However, the peak sensitivity frequency is not as low as that of zebrafish (500-1,000 Hz). This is not an insignificant finding, and it’s conceivable that this ancient Otophysan fish achieved a higher hearing frequency.”

This discovery indicates that at least two transitions from marine to freshwater species occurred during the evolution of otolaryngology.

Researchers estimate the divergence times for ear plants migrating from ocean to freshwater habitats occurred around 154 million years ago (late Jurassic period), following the fragmentation of Pangaea around 200 million years ago.

“Dinosaurs are fascinating, attracting significant attention, which means we know a lot about them. However, there’s still much to uncover regarding the diversity of prehistoric freshwater fish.”

“Many keys to understanding the origins of the groups that currently dominate rivers and lakes worldwide can be found in Canadian fossil sites.”

A paper detailing these findings was published in the journal Science on October 2nd.

____

Juan Liu et al. 2025. Marine origin and freshwater radiation of ENT. Science 390 (6768): 65-69; doi: 10.1126/science.adr4494

Source: www.sci.news

Fish Rescue Secures New Scientist Editor Award at EarthPhoto 2025

Posted on by
Reply

Yurok Tribal member and biologist working with engineers to set up a fish trap on a tributary of the Klamath River in California

Vivian Wan

The essence of this image lies in restoring the traditional way of life, captured by Vivienne Wang, whose work is part of the series that earned the New Scientist Editor’s Award at the Earth Photo 2025 Competition.

The photograph illustrates the Yurok community collaborating with biologists and engineers to install a rotary screw trap on the Trinity River, a key tributary of the Klamath River in Willow Creek, California. The team employs fish traps to assess the health of the salmon and examine their migration behaviors.

The Klamath Basin is central to Yurok existence, holding significant cultural and spiritual importance through its rich waters that support Chinook salmon (Oncorhynchus tshawytscha). However, 19th-century colonization displaced the Yurok tribe and depleted local resources through mining, logging, and damming efforts.

Climate change and diverted river flows have severely affected salmon populations. A new irrigation policy in 2002 resulted in the deaths of tens of thousands of Chinook salmon in the Klamath River, adding urgency to the decades-long initiative to remove river dams. Notably, the last dam on this river was demolished last year.

For Wang, the mission was to illuminate how Indigenous communities could lead the charge for environmental justice. “We aspire for viewers to gain respect for the resilience, culture, and ongoing struggle of the Yurok people as they work to safeguard the Klamath Basin,” she remarks.

In the image below, Yurok Fisheries technician Hunter Mattz examines monitors that reveal enlarged salmon scales, gathering valuable insights into mortality factors sourced from fishing and natural causes. This information is crucial for determining sustainable catch limits and spawning goals, as well as assessing run sizes, which indicate the number of salmon entering a river or stream within a specific timeframe.

Mattz, a third-year Yurok fishery technician, inspects a monitor showing a magnified salmon scale

Vivian Wan

In this scene, Mattz holds a slender tag on a needle, contributing critical data to the fish monitoring research program.

Mattz displays a small fish tag providing essential data to fish monitoring initiatives

Vivian Wan

Mattz also manages the Net Harvest Project, which entails traversing over 70km from the Pacific Ocean to the estuary’s mouth and into the heart of the Klamath Basin, including stretches beyond Blue Creeks in California. Collecting data on fish species caught by local residents through nets has been pivotal in securing funding for conservation efforts in the Klamath region.

Hunter Mattz’ portrait, who is also collecting data on fish species caught by local residents

Vivian Wan

All winners of the Earth Photography Competition were chosen by a panel including New Scientist photo editor Tim Bodhuis and David Stock, director of editorial videos. Before touring the UK, make sure to visit the Earth Photo 2025 exhibition at London’s Royal Geographical Society until August 20th.

topic:

Source: www.newscientist.com

New Research Reveals the Ancient Origins of Fish Biofluorescence

Posted on by
Reply

Biofluorescence, the process of absorbing high-energy light and re-emitting it as low-energy wavelengths, has been observed in various vertebrate and invertebrate lineages, particularly among fish. Research conducted by the American Museum of Natural History indicates that fish biofluorescence can be traced back at least 112 million years and has evolved over 100 times, predominantly in fish inhabiting coral reefs.

Phylogenesis of teleosts showing ancestral state reconstruction (absence/present) of biological fluorescence. Image credit: Carr et al., doi: 10.1038/s41467-025-59843-7.

“Researchers have long known that biological fluorescence is prevalent in marine creatures, including sea turtles and corals, particularly among fish,” stated PhD Emily Kerr, a student at the American Museum of Natural History.

“To truly grasp the reasons and methods behind this unique adaptation, we need to explore the evolutionary background and the variety of biofluorescence currently utilized for camouflage, predation, or reproduction.”

In a first study published in the journal Natural Communication, Carr and colleagues investigated all known biological fluorescent extents, focusing on a species of bony fish, which comprises the largest living vertebrate group today.

This research identified 459 biological fluorescent species, including 48 previously unrecognized as biologically fluorescent.

The researchers discovered that biological fluorescence has evolved over 100 times in marine teleost fish, dating back to approximately 112 million years ago, with the initial occurrence found in eels.

Furthermore, fish species residing in or near coral reefs developed biological fluorescence approximately ten times faster than their non-reef counterparts, leading to a surge in fluorescent species following the mass extinction event around 66 million years ago that wiped out non-avian dinosaurs.

“This pattern coincides with the emergence of modern coral reefs and the rapid infiltration of fish into these environments, particularly after a significant loss of coral diversity due to the Cretaceous extinction,” Kerr explained.

“These relationships imply that the rise of contemporary coral reefs may have spurred the diversification of fluorescence in reef-associated teleost fish.”

Among the 459 documented biological fluorescent extents indicated in this study, the majority are linked to coral reefs.

In a second survey published in the journal PLOS 1, Kerr and co-authors employed a specialized photographic system with ultraviolet and blue excitation lights, alongside emission filters, to analyze the wavelengths emitted by fish from the ichthyology collection at the American Museum of Natural History.

These specimens, collected over the past 15 years during museum expeditions to locations like the Solomon Islands, Greenland, and Thailand, had shown fluorescence previously; however, the full spectrum of biological fluorescence emissions remained unexplored.

This study unveiled a broader diversity in the colors emitted by teleost fish, with some displaying at least six distinct fluorescence emission peaks across various wavelengths, surpassing prior reports.

“The unexpected variation observed among a wide array of these fluorescent fish suggests that they may utilize highly diverse and intricate signaling systems based on species-specific fluorescent emission patterns.”

“As these studies illustrate, biological fluorescence is extensive and remarkably phenotypically diverse among marine fish.”

“Our goal is to enhance our understanding of how fluorescence operates within these varied marine ecosystems and its role in evolutionary diversification.”

“The multitude of fluorescence emission wavelengths identified in this study could significantly impact the discovery of new fluorescent molecules that are routinely employed in biomedical applications, including the diagnosis and treatment of fluorescence-related ailments.”

____

Carr et al. 2025. The extensive evolution of repeated biological fluorescence in marine fish. Nat Commun 16, 4826; doi:10.1038/s41467-025-59843-7

Carr et al. 2025. Marine fish display exceptional variability in biological fluorescence emission spectra. PLOS 1 20 (6): E0316789; doi: 10.1371/journal.pone.0316789

Source: www.sci.news

New Research Reveals Clown Anemone Fish Shrink to Survive Heat Stress

Posted on by
Reply

You can identify it from its leading role in the film Finding NEMO: the Clown Anemone Fish (Amphiprion percula). This research addresses methods to minimize social conflict, as discussed in the paper published in the journal Advances in Science.

Versteeg et al. We studied the growth of individual clown anemone fish during marine heat waves. Image credit: Beatrice.

“The Clown Anemone Fish and its stunning sea anemone host, Radianthus magnificus,” expressed Melissa Verstegue, a doctoral researcher at Newcastle University, alongside her colleague Melissa Vertegue.

“Anemonefish inhabit coral reefs in the Indo-Pacific, where heat stress events are becoming increasingly frequent and severe, yet reef dwellers often approach their thermal limits.”

“These heat stress events can adversely impact both the anemones and the clownfish that reside within them.”

“The clown anemone fish exist in a social structure comprising dominant breeding pairs and several subordinate, non-breeding individuals.”

“The growth and size of clown anemone fish correlate with their environmental and social conditions, with dominant individuals growing to match the size of their anemone and the resources available. Subordinate fish maintain a specific size ratio to avoid conflict and potential eviction.”

In this research, Versteeg and co-authors measured the lengths of 134 clownfish over five months and tracked water temperatures every 4-6 days during increasingly common ocean heat waves exacerbated by climate change.

This collaboration was conducted with the Mahonia Na Dari Conservation and Research Centre in Kimbe Bay, Papua New Guinea.

The findings reveal that clownfish can adjust their body length, potentially shrinking in response to heat stress.

This reduction increases an individual’s chances of surviving heat stress events by up to 78%.

The study also indicates that coordination among clownfish is crucial, as they are more likely to survive heat waves when paired with their breeding partners.

This marks the first documented instance of coral reef fish reducing body length in response to environmental and social factors.

“This doesn’t merely lead to weight loss under stress; these fish genuinely become shorter,” notes Versteeg.

“We are still uncertain about the exact mechanisms behind this, but it’s known that a few other species can also exhibit similar shrinkage.”

“For example, marine iguanas can reabsorb some of their bone material and decrease in size during environmental stress.”

“We were astonished to observe these fish shrink; we rigorously measured each individual across five months.”

“Ultimately, we discovered size reduction was quite common within this population.”

“During our study, 100 out of the 134 fish observed shrank.”

“It was surprising to witness how rapidly clownfish can adapt to changing environments, showcasing their ability to alter size both as individuals and breeding pairs in response to heat stress, which serves as an effective survival strategy.”

The authors also highlight that individual size reduction may help explain the declining sizes of fish in our oceans.

“Our results affirm that individual clownfish can shrink in response to heat stress, potentially affected by social dynamics and exhibiting improved survival potential.”

“If this phenomenon of individual size reduction is widespread across various fish species, many could show decreased sizes, suggesting a viable hypothesis for further research in this area.”

____

Melissa A. Verstigue et al. 2025. Individual clown anemone fish shrink to survive heat stress and social conflict. Advances in Science 11 (21); doi:10.1126/sciadv.adt7079

Source: www.sci.news

The Initial Teeth: Sensory Organs of Ancient Fish Skin

Posted on by
Reply

CT scan of the front of a skate depicting a hard, tooth-like dentition (orange) on its skin

Yara Haridi

Recent analysis of animal fossils suggests that teeth initially developed as sensory organs rather than for chewing. The earliest tooth-like structure seems to have originated as a sensitive nodule in the skin of primitive fish, allowing them to detect variations in the surrounding water.

The findings support the long-held belief that teeth originally evolved outside the mouth, as noted by Yara Haridi from the University of Chicago.

While some evidence exists to back this theory, significant questions remain. “What purpose do all these teeth on the exterior serve?” queries Khalidi. One possibility is that they functioned as defensive armor; however, Khalidi proposes an additional theory: “It’s beneficial to protect oneself with tough materials, but imagine if those materials could also enhance sensory perception of the environment?”

True teeth are exclusively found in vertebrates, such as fish and mammals. Although some invertebrates possess dental structures, their underlying tissues are fundamentally different. This indicates that teeth originated with the evolution of the earliest vertebrates: fishes.

Khalidi and her research team scrutinized fossils claimed to be the oldest examples of fish teeth, utilizing advanced synchrotron scanning techniques.

They examined fragments of fossils from the genus Anatrepis, which spanned from the late Cambrian (539 to 487 million years ago) to the early Ordovician period (487 to 443 million years ago). These organisms featured a hard exoskeleton with perforations.

These perforations were interpreted as dentin tubules, which are one of the hard tissues composing teeth. In human teeth, dentin serves multiple functions, including sensation and the detection of temperature and pain.

This led to the hypothesis that these tubules may be the precursors of teeth. Anatrepis represents early fish.

However, Haridi and her colleagues found no such evidence. “We observed the internal structure [of the tubules],” she states. Their examination revealed that the tubules most closely resemble structures known as sensilla, which are found in the exoskeletons of insects and spiders.

This means that Anatrepis are arthropods rather than fish, implying that their tubules do not directly lead to the evolution of teeth.

“Dentin likely emerged as a novel feature in vertebrates, but the hardened external sensory capabilities existed much earlier in invertebrates,” remarks Gareth Fraser from the University of Florida, who was not involved in the research.

Beyond Anatrepis, the earliest known true teeth belong to Ellipticus, which dates exclusively to the Ordovician period. These possess actual dentin found in the skin’s teeth.

Khalidi suggests that like the invertebrate Anatrepis, early vertebrates such as Ellipticus evolved independently to develop skin structures, where sensory nodules had undergone significant evolution. “These two entirely different organisms had to navigate the ancient ocean’s muddy terrain,” she explains. Significantly, the study also indicates that some modern fish skin still retains nerve endings, indicating sensory functionality.

As certain fish transitioned into active predators, they required a method for securing prey, leading to the evolution of hard teeth that moved to their mouths for biting.

“Based on the available data, tooth-like structures may have initially evolved in the skin of ancient vertebrates before migrating into the mouth, evolving into teeth,” Fraser concludes.

topics:

Source: www.newscientist.com

Newly Discovered Shallow Water Fish Species in Portugal

Posted on by
Reply

Paleontologists have announced the discovery of a new genus and species of Balacromian Ikuchosaur, based on a fossilized skull found in the Agua de Maderos Formation in Portugal.

Gadusaurus Aqualigneus. Image credit: Pratas e Sousa et al., doi: 10.4202/app.01199.2024.

The newly identified species thrived in the early Jurassic oceans around 193 million years ago.

It has been scientifically designated as Gadusaurus Aqualigneus; this marine reptile is a small Ikchosaur, measuring approximately 2 m (6.6 feet) in length.

“Iktiosaurus was a group of Mesozoic reptiles renowned for their adaptation back to marine life,” explained Dr. Joan Platas et Sousa, a researcher from Nova de Lisboa University.

“These creatures existed from the early Triassic to the late Cretaceous, but early Jurassic fish fauna is most commonly found in the European fossil record.”

“While some western regions are rich in marine deposits, southern areas like the Iberian Peninsula (encompassing Portugal and Spain) have very few and fragmented records.”

The nearly complete skull of Gadusaurus Aqualigneus was found in a planarized state, measuring about 35.2 cm (13.9 inches) in length, in the Agua de Madeiros Formation in 2021.

“The specimens we analyzed were collected in mainland Portugal, specifically in the San Pedro de Moel area,” the paleontologist stated.

“The fossil block was located in the sands of Agua de Maderos Beach, at a stream marking the boundary between Marinha Grande and Alcobaza municipalities.”

“This region lies within the Lusitania Basin, which is situated on the passive margin of Western Iberia in the Atlantic, providing exceptional marine records from the Lower Jurassic,” they added.

“The Lusitania Basin is a long, narrow structure bordered to the east by the Iberia Massif and to the west by the Valiskan Berrenga Horst.”

“The basin’s development coincided with the opening of the Atlantic Ocean, displaying various sedimentary facies from the upper Triassic to the upper Cretaceous.”

Phylogenetic analysis places Gadusaurus Aqualigneus within the Ichthyosaur Clade Baracromia, part of the Neoichthyosaur and Parvipelvia Clades.

“This specimen represents the most complete and well-preserved remains of Uoshima described so far on the Iberian Peninsula,” the researchers noted.

“Moreover, it is the first new species of this marine reptile group documented in Iberia.”

“This specimen predates the Toarcian Marine Anoxia Event, which is believed to have affected the lifestyle of later Ichthiosaurus species.”

“It’s reasonable to assume that ecological events during this period may have similarly influenced the lifestyle of this type, though further studies are essential.”

The discovery of Gadusaurus Aqualigneus will be detailed in a new paper published online in the journal Acta Palaeontologica Polonica.

____

J. Platas E. Sousa et al. 2025. A new Ichaosaurus from the lower Jurassic of Portugal (Iberian Peninsula). Acta Palaeontologica Polonica 70(1):179-192; doi:10.4202/app.01199.2024

Source: www.sci.news

Opportunistic Miocene freshwater fish fed on cyclic basement diet

Posted on by
Reply

Paleontologists from the Australian Museum Institute, the University of New South Wales, the University of Canberra and CSIRO describe a new species of Osmel-type fish from fossilized bodies found in New South Wales, Australia. The fish’s preserved stomach content indicates an opportunistic bottom-pore-like diet, as evidenced by the ruins of many phantom midge larvae, two insect wings, and bivalve remnants.

Habits and fin locations Fell Aspis Block Sea. Scale bar – 8 mm. Image credit: McCurry et al. , doi: 10.1080/02724634.2024.2445684.

The newly described fish species, which lived in the Myosense period about 15 million years ago, belonged to the Osmerforfos (freshwater smell and its allies).

Named after Professor Jocchen Bloc of Australian National University Fell Aspis Block Sea It is the first fossil freshwater smell found in Australia.

“I am extremely proud that this world’s first discovery was named after me,” Professor Brocks said.

“This discovery opens a new pathway to understanding the evolutionary history of Australia’s freshwater fish species and ancient ecosystems.”

Professor Brox discovered several fossils Fell Aspis Block Sea At the McGrath Flat Fossil Site near Gurgon, New South Wales.

“Before the discovery of this fossil, scientists lacked concrete evidence to identify how this group of fish evolved over time and when they arrived in Australia,” said Dr. Matthew McCurry, of the Australian Museum Institute and the University of New South Wales.

“Fell Aspis Block Sea This is the first fossil freshwater Australian confectionery found in Australia. ”

“The discovery of fossil freshwater fish 15 million years ago provides an unprecedented opportunity to understand Australia’s ancient ecosystems and the evolution of fish species.”

“The fossil is part of a diverse range of fish species in Australia, including species such as Australian greyling and Australian confectionery.”

“But without the fossils, it would have been difficult to tell exactly when the group had arrived in Australia and whether they had changed at all over time.”

Stored stomach contents Fell Aspis Block Sea It offers paleontologists a glimpse into the behavior of these ancient species.

“We know that now Fell Aspis Block Sea Although they provided an invertebrate range, the most common prey was small phantom midge larvae,” Dr. McCurry said.

“One of the fossils shows parasites attached to fish tails. It is young freshwater that burns glotidium.”

“These boys Mussarsatach are riding up and down streams on the gills and tails of fish.”

“This little fish is one of the most beautiful fossils I’ve found at McGrath Flat, and it was a real surprise to me to find the first vertebrate among the abundant fossils of plants and insects,” Professor Brocks said.

One of the most exciting aspects of the piece was that they were able to convey the colour of Fell Aspis Block Sea.

Dr. Michael Frise, a paleontologist at the University of Canberra, said:

“We were able to use a powerful microscope to see structures that produce small colours known as melanosomes.”

“Fossilized melanosomes have previously allowed paleontologists to reconstruct feather colors, but melanosomes have never been used to reconstruct color patterns in long-extinct fish species.”

paper The survey results were published this week Journal of Vertebrate Palaeontology.

____

Matthew R. McCurry et al. Paleontology of a new Osmar type fish species from Australia. Journal of Vertebrate PalaeontologyPublished online on March 17th, 2025. doi:10.1080/02724634.2024.245684

Source: www.sci.news

Why Wild-Caught Fish is More Sustainable Than Farmed Fish

Posted on by
Reply

Aquaculture sustainability claims are greatly exaggerated

VIKEN KANTARCI/AFP via Getty Images

It has been argued that fish farming is a sustainable food source that helps feed the growing world population while protecting wild fish populations, but this is not true.

“Aquaculture is not a substitute for catching wild fish from the ocean,” he says. matthew hayek at New York University. “In fact, it relies on catching wild fish from the ocean.”

Hayek and colleagues showed that the amount of wild fish killed to feed farmed fish is 27 to 307 percent higher than previous estimates.

According to Hayek, farmed carnivorous fish eat wild fish caught in the ocean at several times the weight that would be obtained in aquaculture. For example, producing 1 kilogram of salmon may require 4 to 5 kilograms of wild fish.

However, while the demand for farmed fish is increasing, the amount of wild fish caught is not increasing. “In multiple fisheries, we are moving towards a scarcity of fish in the ocean,” Hayek says.

As a result, as the aquaculture industry expands, an increasing proportion of the world's wild fish catch is used as feed for farmed fish.

This means people in places like Southeast Asia and West Africa can no longer afford to buy fish. The fish is highly valuable as a source of farmed fishmeal and fish oil, team members say. Patricia Majolf At the conservation organization Oceana.

Increasing the proportion of plant-based products in the diet of carnivorous fish, or raising omnivorous or herbivorous fish such as tilapia, carp, or catfish, creates another set of problems. Feeding fish with human-edible plant-based food requires more land and water to produce fish food, leading to problems such as deforestation.

“These sectors are growing so rapidly that we are now supplying them with many times more crops from land than before,” says Hayek.

“As long as you're eating animals, you're not immune to some kind of shock somewhere,” he says. “Raising animals requires more resources to nurture and grow their bodies than can be obtained by eating them. It's a basic fact of biology.”

But farmed shellfish, such as mussels, which are eaten by filtering seawater, are far more sustainable, he says.

There are several reasons why Hayek's team's estimate of the amount of wild fish needed to produce a given amount of farmed fish is much higher than past estimates. For one thing, Hayek said the team used a wider range of sources than previous studies, meaning there is less chance of statistical bias.

The researchers also counted all the fish used to produce fishmeal and fish oil, as well as those caught as feed for farmed fish.

Finally, the researchers also estimated the number of fish that were killed but not brought to market. Unwanted species are often discarded from fishing vessels, but usually do not survive. Sometimes they leave the seine slightly open to let unwanted fish escape, but they often get injured and die.

Even ignoring these additional deaths, the conclusion remains that the amount of wild fish killed to feed farmed fish is higher than previously estimated, Hayek said. But counting them adds 20 to 50 percent to the total, he says.

“They show that the use of fishmeal and fish oil in aquaculture is more complex than many industry analysts estimate.” Stefano Longo at the University of Gothenburg, Sweden. “Fishmeal and fish oil inputs in aquaculture systems are probably underestimated, and possibly significantly underestimated.”

topic:

Source: www.newscientist.com

Fish use mirrors to assess their size and determine their likelihood of winning a confrontation

Posted on by
Reply

Bluestreak Cleaner checking himself out in the mirror

Osaka Metropolitan University

Before deciding whether to fight another fish, wrasse look at their own reflection in the mirror to gauge their size.

Blue Streak Cleaner Lass (Loveroid) are astonishingly bright. This finger-sized coral reef fish is the first to pass the mirror test, a common assessment of whether an animal can recognize its own body and not another animal in a mirror. Researchers discovered that these wrasses use their own reflection to build an image of their own body size and compare it to others.

beginning, Taiga Kobayashi Researchers at Osaka Metropolitan University in Japan conducted an experiment to see if fish were willing to attack. They held up images of different wrasses, each 10 percent larger or smaller than the real fish, against the glass wall of an aquarium. Regardless of the size of the model fish in the photo, the territorial wrasses put up a fight.

The researchers then repeated the test with additional mirrors, and the fish saw their own reflection in the mirror, but when the researchers held up pictures of larger or smaller wrasses on the glass plate, the fish chose to fight only the smaller rivals.

“This was unexpected, as this fish has always been known to be aggressive towards rivals, regardless of its size,” Kobayashi says.

Because the tanks are partitioned, the wrasses can't see both themselves and pictures of rival fish at the same time, so the scientists think the fish must be comparing the pictures to a mental approximation of their own size.

How did wrasses develop this ability, given that they evolved in an environment without mirrors? In both the lab and in the wild, it's advantageous for fish to know the size of their opponent before fighting, Kobayashi says. In other words, the fish were smart enough to use the mirror as a decision-making tool.

topic:

Source: www.newscientist.com

Toothed birds in the Cretaceous era primarily consumed gymnosperm fruits, not fish.

Posted on by
Reply

Paleontologists found fossilized seeds of gymnosperms, relatives of today’s conifers and ginkgo trees, in the stomachs of two of the specimens. Longipteryx caoyangensis One of the oldest known birds, and also one of the strangest. This discovery shows that these birds ate fruit, despite the long-held assumption that they were fish eaters, and the more recent hypothesis that they ate insects with their incredibly strong teeth.

Skull Longipteryx caoyangensis Image courtesy of Xiaoli Wang.

Longipteryx caoyangensis It lived in what is now northeastern China during the Cretaceous period, about 120 million years ago.

First described in 2000, this ancient bird had a long skull and teeth only at the tip of its beak.

“Tooth enamel is the hardest substance in the body. Longipteryx” Human tooth enamel is 50 microns thick,” says Alex Clark, a doctoral student at the Field Museum and the University of Chicago.

“That’s the same thickness as the enamel of a large carnivorous dinosaur. Allosaurus It weighed 4,000 pounds. Longipteryx It was about the size of a blue jay.”

Scientists have previously found that the elongated skull of a kingfisher Longipteryx caoyangensis This means they hunted fish, but this hypothesis has been called into question by a number of studies.

“There are other fossil birds. Janornis “We know they ate fish because specimens have been found with preserved stomach contents, and fish tend to preserve well,” said Dr. Jingmai O’Connor, associate curator of fossil reptiles at the Field Museum.

“In addition, these fish-eating birds had many teeth throughout their beaks. Longipteryx “It only has teeth at the tip of its beak. That doesn’t make sense.”

but, Longipteryx caoyangensis In some cases, animals have been found with fossilized food still in their stomachs, allowing scientists to determine what they had been eating.

In the new study, paleontologists examined two new specimens of this species.

They found that the small round structures in the bird’s stomach Gymnosperms seed.

Since Longipteryx caoyangensis Since they lived in a temperate climate, it is unlikely that they ate fruit all year round.

The authors speculate that when fruit was unavailable, they may have had a mixed diet that included insects.

Longipteryx caoyangensis Part of a larger group of prehistoric birds called enantiornithines, the discovery marks the first time that scientists have found the stomach contents of an enantiornithine in China’s Jehol Biota, despite the discovery of thousands of fossils.

“It’s always puzzling not to know what they were eating, but this study points to a larger problem in palaeontology, which is that the physical characteristics of fossils don’t always tell the whole story about what animals were eating or how they lived,” Dr O’Connor said.

Since Longipteryx caoyangensis It apparently did not hunt fish, which raises the question of what it used its long, pointed beak and unusually strong teeth for.

“The thick enamel seems to be overpowering and weaponized,” Clark said.

“One of the most common skeletal parts that birds use in aggressive displays is the proboscis, or beak.”

“Using the beak as a weapon makes sense because it keeps the weapon away from the rest of the body and helps prevent injury.”

“Modern birds don’t have teeth, but there are some really cool little hummingbirds that have keratinous projections near the tip of their snouts. Longipteryx And they are using it as a weapon to fight each other,” Dr O’Connor added.

“Hummingbird beaks have evolved at least seven times, allowing them to compete for limited resources.”

of Survey results Published in the journal today Current Biology.

_____

Jinmai O’Connor others Direct evidence for frugivory in Mesozoic birds Longipteryx This is inconsistent with morphological indicators of diet. Current Biology Published online September 10, 2024; doi: 10.1016/j.cub.2024.08.012

Source: www.sci.news

New Fish Species Found in Mauritanian Waters by Marine Biologists

Posted on by
Reply

A new species of three-bearded rockfish has been described from a specimen taken from a depth of 595 metres in the Tanoudre Valley, off the coast of Mauritania.

Guidelopsarus mauritanicus Hiding under a branching whitish bryozoan Serena reference. Lucida Image courtesy of Tomas Lundelf, University of Gothenburg.

order Cod These include some of the most important species for commercial fisheries today.

There are also small species in this genus, such as the Three-bearded Bulbul. Guide Lopezal Although it has little commercial value, its range is surprisingly wide.

“More than a quarter of all commercially caught marine fish in the world belong to the cod family. Cod family” These include fish species such as Atlantic cod, Alaskan pollock and haddock, which are particularly economically important,” said Dr. Alexander Norn, researcher at Senckenberg am Meer and the University of Bremen.

“However, the Gadidae family also includes much smaller, little known and less studied fish families, such as the Sardinae (Guidelopsalidae), of little commercial value but astonishingly wide in scope.”

The newly described species lives in deep-sea coral reefs off the coast of Mauritania.

“This is the site of the world's largest deep-sea coral reef system, the Mauritanian Wall. The reef stretches for at least 580 kilometres and is 80-100 metres high,” the biologists said.

Scientific Name Guidelopsarus mauritanicus The new species is just 7.3 centimetres long.

this is, Guide Lopezal The species was collected from Tasmania, the most remote geographic location of the samples the team studied.

“Guidelopsarus mauritanicus “It can be distinguished from other fish of the same species based on a combination of different characteristics, including large eyes, a head that takes up a quarter of its body length, long, slender pelvic fins and pink body colour,” Dr Norn said.

“Genetic analysis confirmed that this is a previously undescribed species.”

“Guidelopsarus mauritanicus They were caught with the help of grubs, along with a variety of live deep-sea animals, including framework-forming stony corals and other corals. Desmophyllum pertussum or red deep sea gorgonian Swiftia PhaetonIt also contains colonies of large sponges, bryozoans, starfish, annelids, decapod crustaceans, snails and bivalve mollusks.”

“Also, in the video footage, Guidelopsarus mauritanicus They live exclusively in deep sea coral ecosystems. One of the specimens we saw had whitish spots on its skin. This was the only fish we could see hiding under a branching, whitish bryozoan. Serena reference. Lucida.”

a paper The article describing this discovery Journal of Fish Biology.

_____

Alexander H. Norn others. Guidelopsarus mauritanicus (Gadiformes, Gaidropsaridae) A new species of three-baleen redfish from a deep-sea coral ecosystem. The biogeographical distribution of the genus is genetically verified, and notes on its ecology and behavior are provided. Journal of Fish Biology Published online August 16, 2024; doi: 10.1111/jfb.15859

Source: www.sci.news

Folding fins increase the speed of fish movement, as demonstrated by Robot Tuna

Posted on by
Reply

This tuna-inspired robot borrows some nifty tricks from the real fish

Lin, Z. et al. (2024).

The tuna-shaped robot harnesses the secret to the speed and agility of real fish – the ability to selectively fold and extend their fins – which could improve underwater robot design.

Tuna are one of the fastest swimming fish in the ocean, thanks in part to their ability to retract and fold their fins to reduce drag. Chung-Rok Hayashi Researchers from China's Xiamen University and their colleagues investigated how such fins could improve the agility of robots.

The researchers built a 50-centimeter-long tuna-shaped robot that can be controlled by motors attached to its head, a dorsal fin on its back, and a fluke at the end of its tail. The researchers filmed the robot swimming in a pool and tested the effects of flattening or erecting the dorsal fin on the robot's acceleration, direction changes, and steady forward motion.

They found that folding and unfolding the dorsal fin had significant effects on factors such as speed, efficiency and linear acceleration. When the robot tuna was changing direction, keeping the dorsal fin erect increased its speed by about 33%. However, keeping the fin erect when the robot was moving steadily forward reduced the efficiency of its movement by up to 13%, increasing the robot's energy consumption.

Lin says these findings are consistent with how tuna in nature raise their dorsal fin to make fast, precise movements, such as when catching prey, then fold it back to continue swimming. “By designing similar flexible control systems, underwater vehicles can improve balance, navigation, and agility at high speed,” he says.

“Understanding this high level of swimming performance in tuna is intrinsically interesting because it is something that even the best human swimmers cannot achieve.” Frank Fish At West Chester University in Pennsylvania.

But Fish adds that the tail fin may play a bigger role than the dorsal fin in a tuna's swimming ability. His own research Many of these animals have shown this to be especially true when it comes to turning, Fish says. “We measured the turning ability of Pacific bluefin tuna and found that it far surpasses the capabilities of a robot,” he says. This may mean that tuna-inspired robots could also be improved by studying their tails in more detail.

topic:

Source: www.newscientist.com

Unexpected surprise: Giant fish thought to be sunbathing on Oregon beach turns out to be a curiosity

Posted on by
Reply

The name “sunfish” is of Latin origin and means “milestone,” referring to the flat, circular body of this fish, which is known to drift along the ocean’s surface, a move some scientists lightly refer to as “sunbathing.”

But Nygard said the activity serves an important purpose: capturing jellyfish and other gelatinous creatures for prey.

When hunting, sunfish dive deep into cooler waters. Their bodies cannot regulate their body temperature efficiently, so they use the sun to warm themselves. While the fish lie on the surface, birds clean them by eating parasites from their skin.

Nyegaard said there are a few features that distinguish the giant sunfish from the giant sunfish: The giant sunfish’s skin becomes wrinkly as it grows, while the sunfish’s skin is always perfectly smooth.

Unlike normal fish, which have tails, sunfish have wings that are wavy and have a bony structure. The sunfish’s wings are divided into two parts, each of which can move independently.

“We don’t yet know why the two species need different rear structures,” Nygard says, adding that one theory is that the two-part flap could be for maneuvering or agility purposes.

Nygard said sunfish in general remain a mystery to scientists: There are five sunfish species in total, including the hoodwinker, and it’s unclear whether they can or will coexist in the same place.

It’s also unclear whether the hoodwinkers of Australia and New Zealand are related to those in the Pacific Northwest and have somehow migrated across the equator, Nygard said.

Since its discovery, people have been flocking to Gearhart Beach to see the lone hooded winker on the sand.

“This isn’t the first time this has been washed ashore, but it is the largest one to have been washed ashore,” said Tierney Thys, a marine biologist at the California Academy of Sciences.

“Strandings like this remind us that humans live on just 1 percent of the available habitable space on this vast ocean planet,” she said. “Encountering these amazing creatures is humbling and inspiring, and a powerful reminder that we still have much to learn.”

Source: www.nbcnews.com

Could the massive fish lizard be the largest marine reptile ever found, surpassing the megalodon in size?

Posted on by
Reply

Forget about megalodons being scary, there’s a new prehistoric creature in town with jaws that may rival Meg’s in power, making it the largest marine reptile ever identified on Earth.

The giant jawbone of this beast measures over 2 meters (6.6 feet), allowing for a bite force strong enough to crush bones. In comparison, the jawbone of a megalodon, which was about the same size, measured only 0.5 meters (1.6 feet).

Experts believe that this massive new ichthyosaur species was a staggering 25 meters (82 feet) long, similar in size to a modern blue whale. (Megalodon was about 15-20 meters, or 65 feet in length).

The fossilized remains of this creature were found on the Somerset coast.

The research team named this new species Ichthyotitan severnensis, meaning “Giant Fish Lizard of the Severn.” These bones date back to around 202 million years ago, towards the end of the Triassic period, just before the dinosaur extinction event.

The first jawbone of this mysterious species was discovered in 2016, with this recent find confirming its existence.

Dr. Dean Lomax, a paleontologist at the University of Manchester, expressed excitement about the discovery, hoping that more complete specimens may be found in the future.

Lomax and his team compared the two jawbones and found shared unique features, indicating they were from the same geological period.

Ruby Reynolds, an 11-year-old girl, discovered a new salangular on the beach in 2020, leading to further discoveries by her and her team, including the final piece of the jawbone in 2022.

Now 15, Ruby Reynolds has contributed to naming the new species and is already a published scientist, listed as a contributor to research in the journal PLoS ONE.

Read more:

Source: www.sciencefocus.com

Marine reserves do not aid in the recovery of fish populations

Posted on by
Reply

Grunts and gray grunts in Holchan Marine Reserve off the coast of Belize

Pete Oxford/ILCP

Fish populations in Caribbean marine reserves have not recovered, according to a 12-year study. Researchers say poor enforcement of marine protection regulations, coastal development and rising water temperatures are likely to blame.

Stretching for more than 1,000 kilometers along the Caribbean coasts of Belize, Guatemala, Honduras, and Mexico, the Mesoamerican Reef is home to a wide range of wildlife, including more than 500 species of fish and 65 species of coral.

Over the past few decades, governments in these countries have created many marine protected areas (MPAs) with the aim of protecting the precious biodiversity of coral reefs and restoring fish populations that have declined due to overfishing. I did. These areas may prohibit fishing during certain times of the year, prohibit certain types of fishing gear, and restrict other activities such as tourism and mining.

To evaluate the effectiveness of these MPAs, stephen canty Researchers from the Smithsonian Environmental Research Center in Maryland analyzed changes in fish biomass in 111 protected lands and 28 non-protected lands from 2006 to 2018. The data was collected during a survey by a scuba diver as part of the investigation. Initiatives for healthy coral reefs.

The researchers found that adult fish biomass increased in only 11 of the marine protected areas during the study period, indicating an increase in adult fish populations. Meanwhile, adult fish populations declined in 28 of the reserves and remained unchanged in the remaining locations. Less protected sites did see declines, but the declines were often smaller than the most protected sites.

The study found that 11 areas where fish populations have recovered have well-enforced MPA regulations and less fluctuation in sea surface temperatures. Sites with poor recovery showed opposite trends, including poor implementation of conservation measures, increased human activity in coastal areas, and increased temperature anomalies.

“Enforcement plays a huge role in whether some of these areas are successful or not,” Canty says. He suggests that local residents, who make a living from adult fish, should be given a greater role in managing MPAs. It's also important to ensure MPAs are located in areas that are better protected from climate change and easier to manage, he says.

“There's still a lot we don't know about marine protected areas,” team members say Justin Nowakowski, also located at the Smithsonian Environmental Research Center. “Therefore, it is important to be able to look to the past to optimize how he positions and manages his MPAs in the future.”

topic:

Source: www.newscientist.com

The Secret Behind the Star Vegan Chef Who Created Liver-Flavored Dishes: Hiding Fish Under Kale

Posted on by
Reply

Alex Jamison’s veganism gained worldwide recognition after starring in the 2004 film Supersize Me, an influential Academy Award-nominated documentary exploring our fast food culture.

Originally working as a vegan, health-conscious private chef in New York, Jamison’s journey began after a discussion with her then-partner Morgan Spurlock (who directed and starred in the film). The film’s success propelled her to travel to 20 countries, secure a three-book deal, including Vegan Cooking for Dummies, grow a vegan recipe newsletter to over 25,000 subscribers, and land a $7,000 per hour speaking contract across the United States.

In 2012, she started experiencing cravings for non-vegan foods like burgers and salmon, which marked a significant shift from her strict vegan lifestyle. This change, influenced by her health and well-being, also sparked backlash within the vegan community she had once been a prominent figure in.

Alex Jamieson co-starred with ex-husband Morgan Spurlock in the 2004 film Supersize Me. Photo: Everett Collection Inc/Alamy

Her journey toward a plant-based diet began in 2000 due to health issues, leading her to quit her job and become a professional chef specializing in vegan cuisine. This transition defined her identity and kickstarted her career in the health and wellness industry.

By 2013, she made the difficult decision to publicly declare her departure from veganism, which triggered a backlash from the vegan community. Despite losing subscribers, speaking engagements, and facing negative reviews, she embraced her new journey and became a beacon for others struggling with the concept of strict veganism.

Now at 49, she continues to evolve, carving out a new path as a creative leadership coach, author, and activist, while openly admitting to incorporating meat into her diet. Her experience has made her more courageous and willing to embrace change in her life.

Source: www.theguardian.com

Emergency Response Triggered by Unusual Fish Behavior in Florida

Posted on by
Reply

Ripley’s Aquarium plans to introduce up to six small-toed sawfish to the facility. A spokesperson said the majority of the company’s animal care team will assist in the effort, including transporting the sawfish to the Marine Science Research Center to care for it.

Mote Marine Laboratory and Aquarium also said in a release that a quarantine facility for the rescued sawfish is ready and they are eager to help.

“Solving this mystery will require strong collaboration,” said Kathryn Flowers, Mort postdoctoral researcher and lead scientist on the effort.

The problem affects many species of fish off the coast of Florida, said Dean Grubbs, associate director of research at Florida State University’s Coastal Marine Research Institute.

“It goes all the way from very small prey species like pinfish to things like grouper and some stingrays,” he said.

Brehm said there are several theories about what’s going on, but with this type of event it’s difficult to come to an answer right away.

“I’ve heard to some extent that it’s like trying to find a needle in a haystack,” he says. “But it’s very difficult to know which one it is because there are so many different possibilities.”

Florida Fish and Wildlife Conservation Commission said on wednesday They found evidence to rule out several potential causes. The report said the fish did not appear to be suffering from any infectious or bacterial infections, and other factors such as oxygen, salinity and temperature were not suspected to be contributing factors.

The commission’s hotline for sawfish sightings has been in place for years, but the number of calls has increased in the last month.

Shea McKeon, director of marine programs at the American Bird Conservancy, said the group is also closely monitoring the fish situation, but has not yet seen a link to the bird deaths. . To help scientists figure out the root cause, the public can record instances of strange fish behavior they see on the water and upload videos and photos to community science sites like iNaturalist.org he said.

Grubbs said the problem appears to have gotten worse since February.

“We’ve spent the last 15 years studying sawfish, so it’s very sad to see these sawfish die,” he said. “And it’s hard. It’s hard for my students, my graduate students, to see that. It’s definitely painful. We want to get to the bottom of it and find a way to recover from this.” Masu.”

Marissa Parra

Marissa Parra is a national correspondent for NBC News based in Miami, Florida.


Maria Piñero

Maria Piñero is a producer at NBC News.

Jason Abbruzzese contributed.

Source: www.nbcnews.com

Small Fish in the Cyprinidae Family Can Produce Sounds Over 140 dB, Say Ichthyologists

Posted on by
Reply

Danionella cerebrumThis translucent fish species, only 12 mm long, produces high-amplitude sounds exceeding 140 dB (1 µPa relative at a distance of 1 body length). This is comparable to a jet engine taking off at a distance of 100 meters.

Danionella cerebrum It has a pair of extrinsic indirect muscles that house the drumming cartilage. When the sonic muscles contract, they pull the fifth rib forward, pulling on the cartilage and increasing tension. When the cartilage is suddenly released, it rapidly impinges on the swim bladder, producing a short, loud pulse. Bursts of pulses are produced by bilateral alternating or unilateral muscle contractions. In summary, this mechanism allows for loud, stereotypical sounds elicited in structured sequences, making it unique for vertebrate acoustic communication and ultrafast skeletal locomotion that exceeds the limitations of muscle contraction velocity. It will be a solution. Image credit: Ralf Britz, Senckenberg Natural History Collections.

“Oyster oyster shrimp can make crackling noises of up to 250 dB with their claws,” he said. Dr. Ralph Blitzichthyologist at the Senckenberg Natural History Collection.

“The flightless kakapo’s mating call can reach 130 dB, and elephants can make up to 125 dB of noise with their trunks.

“Fish, on the other hand, are generally considered to be fairly quiet members of the animal kingdom.”

“But certain fish species can be surprisingly noisy. For example, male redfin midshipmanfish attract females with an audible vibrato of about 100 Hz and 130 dB.”

In a new study, Dr. Blitz and his colleagues looked into Danionella cerebruma small teleost fish with the smallest brain of any known vertebrate.

“This small fish can emit over 140dB of sound at a distance of 10-12mm, which is comparable to the noise of a plane taking off at a distance of 100m, which is highly unusual for such a fish. 'It's a small size,' Dr. Blitz said.

“We sought to understand how the fish manage this and what mechanisms are involved in this outcome.”

Using a combination of high-speed video, microcomputed tomography, gene expression analysis, and differential methods, the researchers discovered that: Danionella cerebrum Males have unique sound-producing equipment, including drumming cartilage, specialized ribs, and fatigue-resistant muscles.

“This device accelerates the drumming cartilage with a force of more than 2,000g and slams it against the swim bladder, producing rapid and loud pulses,” Dr. Blitz said.

“These pulses chain together to produce calls for bilateral alternating or unilateral muscle contractions.”

Due to its small size and lifelong light transmission, Danionella cerebrum It is a new model organism for biomedical research.

This species lives in the shallow, murky waters of Myanmar.

“It is likely that competition between males in this visually restricted environment contributed to the development of specialized mechanisms for acoustic communication,” Dr Blitz said.

The results of this study cast doubt on the conventional concept that the speed of skeletal movement in vertebrates is limited by muscle movement.

“Understanding unusual adaptations Danionella cerebrum “This extends our knowledge of animal locomotion and highlights the remarkable diversity of propulsion mechanisms in different species,” the authors said.

“This contributes to a broader understanding of evolutionary biology and biomechanics.”

“Sounds made by others are Danionella The species has not yet been studied in detail. It would be interesting to know how their sound production mechanisms differ and how those differences relate to evolutionary adaptations. ”

“Combined with its lifelong transparency, this genus Danionella This provides a unique opportunity to compare the neural mechanisms underlying sound production between different species. ”

of study Published in Proceedings of the National Academy of Sciences.

_____

Verity ANO Cook other. 2024. A superfast sound production mechanism in one of the smallest vertebrates. PNAS 121 (10): e2314017121; doi: 10.1073/pnas.2314017121

Source: www.sci.news

Unusual Fish with Mouth that Extends to Resemble a Trunk

Posted on by
Reply

A hinged mouth that extends its proboscis to feed at the bottom of the aquarium.

Alison Evans

Found only in rivers and forest ponds in West Africa, this fish has a protruding trunk-like snout that allows it to suck in food or breathe air like a snorkel.

hinge(Fractolemus ansorgii) has what biologists call an expandable proboscis, a tubular structure that can be folded onto the head and extended upward or downward. The lips of the proboscis are lined with tooth-like structures made of keratin, which the fish uses to scrape up algae and other debris.

Alison Evans Researchers at George Washington University in Washington, D.C., used dissection, videography, and CT scans to uncover the jaw's complex structure.

Unlike all other fishes, where the jaw joint is located at the back of the mouth, the hinge mouse's jaw joint is located at the front of the head. The lower jaw is tipped back and pointed toward the throat. The upper jaw is connected to the lower jaw by ligaments and is part of the proboscis. “You can think of the upper jaw more or less hanging onto the skin of the proboscis,” Evans says. This is why the structure can extend far from the head.

Hingemouths offer “a novel mechanical solution to a ubiquitous challenge faced by all fish: how to acquire food in viscous fluid media,” Evans says.

She also observed the fish swimming up to the surface and using its proboscis “like a snorkel” to suck in air. This can be a useful feature in forest pools where oxygen levels can be low.

Scientists aren't sure how hinges evolved because fossil evidence is scant. “The family, fractoremus“The family Quneridae is thought to have originated in the mid-Cretaceous period, but no intermediate forms have yet been found in the fossil record,” says Evans.

“The most important thing for me is that scientists remain curious about the world’s little weirdos,” she says.

topic:

Source: www.newscientist.com

The Surprising Noisemaking Abilities of Tiny Fish

Posted on by
Reply

Danionella celebraum male fish

Ralph Blitz/Senkenberg Dresden

One of the world’s smallest fish, measuring just 12 millimeters long, it can make a sound as loud as a firecracker at more than 140 decibels.

Danionella cerebrum It is a small fish that lives in small rivers along the Bago Yoma Mountains in Myanmar.it is smallest known brain of all vertebrates in the world.

“We study this fish primarily for neuroscience because it’s so small and transparent,” he says. verity cook Charité, Faculty of Medicine, University of Berlin, Germany. But the fish are so loud, she says, that she can hear the pulsating sound just by walking in front of the tank.

To investigate how these tiny fish make this sound, Cook and his colleagues gathered groups of three or four fish into small tanks and shot high-speed video.

When a fish makes a sound, the ribs next to the swim bladder (organs that control the buoyancy of the swim bladder) are pulled by special muscles into a small hollowed cartilage area.

“There’s a lot of tension in this contraction,” Cook said. “When it is released rapidly, [the rib] When you hit the swim bladder, it makes a drum sound. “

Based on gene expression analysis, these specialized muscles are more resistant to fatigue than other muscles in the fish, and are therefore able to produce more hits in a row.

It’s unclear why these fish make so much noise. D. cerebrum They typically live in murky, murky waters and may have evolved this behavior to help find each other when visibility is poor, Dr Cook said.

“But the fact that only males make sounds suggests that it is related to aggressive behavior towards other males and mating behavior with females,” she says.

topic:

Source: www.newscientist.com

Decoding the key to aging well with medaka fish

Posted on by
Reply

A study of killifish by the Max Planck Institute revealed that older fish enter a state of starvation due to changes in their adipose tissue. Activating a specific subunit of AMP kinase restores health and longevity in humans, suggesting a new way to promote healthier aging in humans.

Genetic switch rescues aging fish from starvation trap.

Fasting interventions that alternate between fasting and refeeding are generally thought to improve health. However, these interventions do not work well in older animals.

The question is, why?

By studying short-lived killifish, researchers at the Max Planck Institute for the Biology of Aging in Cologne found that older fish deviate from the fasting and refeeding cycles of their youth, and even when they consume food, they permanently It was shown that the body enters a state of fasting. However, the benefits of post-fasting refeeding in old medaka fish can be restored by genetically activating specific subunits of AMP kinase, an important sensor of cellular energy.

These mutant fish experience improved health and longevity and require both fasting and refeeding to provide health benefits, which have been shown to act through AMP kinase. I am.

Medaka ages rapidly. The bright colors of their youth fade in just a few months.Credit: K. Link / Max Planck Institute for the Biology of Aging

It has already been shown in many model organisms that reducing food intake through calorie restriction or periods of fasting has positive effects on health. However, it is difficult for humans to reduce the amount they eat throughout their lifetime. To find the optimal timing for fasting, researchers introduced fasting interventions at different ages, but found that these interventions in older adults did not provide the same benefits as in younger animals.

A research team in Cologne, Germany, now investigated the effects of age-related fasting on medaka fish. Medaka is a rapidly aging fish that grows from young to old in just a few months. The researchers either starved young and old fish for several days or fed them twice a day. They found that the visceral adipose (adipose) tissue of older fish became less responsive to feeding. “Adipose tissue is known to respond most strongly to changes in food intake and plays an important role in metabolism, which is why we looked at it more closely,” said lead author of the study. explains Roberto Ripa.

It is important to alternate between fasting and meals

The researchers found that, unable to respond to the feeding phase, the adipose tissue of old fish enters a permanent state of starvation, where energy metabolism ceases, protein production decreases, and tissue does not renew. “We thought that older fish would be unable to switch to fasting after feeding. Surprisingly, the opposite was true, and older fish would be unable to switch to fasting after feeding. , they were in a state of permanent starvation,” said study leader Adam Antebi, director of the Max Planck Institute for the Biology of Aging.

Permanently fasted adipose tissue

When the researchers looked more closely at how the fat tissue of old fish differs from that of young fish, they discovered a specific protein called AMP kinase. This kinase is a cellular energy sensor and is composed of various subunits, among which the activity of the γ1 subunit decreases with age. When scientists genetically engineered this subunit to increase its activity, the starvation-like state was overcome, and the old fish became healthier and lived longer.

human aging

Interestingly, an association was also found between the γ1 subunit and human aging. Significantly lower levels of certain subunits were measured in samples from older patients. Additionally, in human samples, we were able to show that people who are less frail at older ages have higher levels of the γ1 subunit.

“Of course, we still don’t know whether the human γ1 subunit is actually involved in healthy aging. The next step is to find a molecule that precisely activates this subunit and use it to “We investigate whether this can have a positive impact on aging,” explains Adam Antebi.

Reference: “Refeeding related AMPK”γ1 Complex activity is a hallmark of health and longevity.” Roberto Ripa, Eugen Barrissa, Joachim D. Steiner, Raymond Lavoie, Andrea Annibal, Nadine Hocher, Christian Razza, Luca Dolfi, Chiara Calabrese, By Anna M. Meyer, Maria Cristina Polidori, and Roman – Ulrich Müller and Adam Antebi, November 13, 2023, natural aging.
DOI: 10.1038/s43587-023-00521-y

Source: scitechdaily.com