Articles tagged with Ichthyology
A study found that pallid sturgeon stocked in the lower basin of Nebraska, Iowa, and Missouri live an average of just 19.8 years, nearly three times shorter than in the upper basin. The researchers also discovered that females in the lower basin weighed an average of seven times less and spawned fewer eggs over their lifetimes.
Researchers found a 45% decrease in fish biomass over a decade, attributed to nitrogen pollution from sewage and golf courses. Sustainable fishing practices, such as gear restrictions, can help mitigate losses and support reef resilience.
Researchers found that high CO2 concentrations in water make fish grow smaller, with a growth deficit of between five and ten percent. Fish living at less ideal temperatures and more CO2 experienced greater reductions in growth.
Researchers found that small fish on hot Arabian Gulf reefs are less diverse and abundant than those on cooler reefs, despite similar coral cover. The thermal extremes may be an energetically challenging environment for these smallest marine vertebrates.
Researchers have discovered that at least 16 species of deep-sea fish have evolved ultra-black skin that absorbs most of the light, allowing them to blend in and avoid detection. The unique shape and arrangement of melanosomes in these fish's skin cells enables this remarkable camouflage.
A new study found that older women who eat more fish may counteract the negative effects of air pollution on their brains. The research discovered a link between higher levels of omega-3 fatty acids and greater brain volumes, particularly in white matter and the hippocampus.
A new study reveals that fish spawning and embryos are more susceptible to temperature changes than other life stages, with up to 60% of species at risk within a century. The findings highlight the critical importance of considering thermal bottlenecks across an organism's lifecycle in climate risk assessments.
Fish are highly sensitive to heat during mating and embryonic stages due to temperature-dependent cardiovascular strain. Climate change may force up to 60% of all fish species to abandon traditional spawning areas.
A new study reveals that traditional predictions of species movement due to climate change may be inaccurate. Broad diets were found to be a crucial factor in the establishment and persistence of tropical fish in cooler areas.
A new study led by UNSW reveals that blenny fish's transition from water to land is driven by dietary flexibility, which allows them to survive and thrive on land. The researchers found that once on land, these remarkable creatures face restrictions on food availability, triggering major evolutionary changes in their morphology.
A new study reveals that great white sharks spend most of their time foraging just above the seabed, contrary to the common stereotype of a shark's dorsal fin above the surface. The diet of juvenile white sharks consists mainly of fish species that live on or near the seafloor.
Researchers found that removing just the top 26 meters of a platform results in an average loss of only 10% of fish biomass, while completely removing it leads to a 95% reduction. Partial removal supports significantly more fish biomass than complete removal.
A new study found that the diets of reef fish dictate how fast different species evolve, with big vegetarian fish driving biodiversity. The study's authors built an evolutionary tree of life for nearly all fishes associated with reefs, examining variation in rates of species formation and asking what drives it.
A diet rich in fish omega-3 fatty acids modulates lipoprotein particles, reducing triglycerides transported by any type of lipoprotein. The study found that increased consumption of LDL cholesterol from fish is associated with larger, less atherogenic LDL particles.
A team of scientists from Nagoya University found that starving medaka larvae can cause sex reversal, revealing a potential link to environmental factors and metabolic processes. The study may provide insights into rare conditions in humans and other vertebrates where individuals have characteristics of both sexes.
Using integrated information theory, researchers from the University of Tsukuba studied schools of Plecoglossus altivelis fish and found a discontinuity between three- and four-fish schools. The study revealed that leadership emerges in larger groups, improving understanding of collective behavior dynamics.
A marine heatwave in 2015-16 triggered different genetic responses in five coral reef fish species, showing varying levels of vulnerability to climate change. The study found common molecular pathways associated with increased oxygen uptake and cellular stress responses among all species.
Researchers found that fish and zooplankton behavior are disrupted by artificial light during the polar night, affecting stock assessments of commercial and non-commercial fish species. They also discovered that this disruption occurs as far down as the Mesopelagic Zone, where it can impact fisheries surveys.
The Calusa kingdom relied primarily on fishing due to the watercourts, which were built around A.D. 1300 and served as short-term holding pens for fish before consumption or preservation. The structure's design required an understanding of daily and seasonal tides, hydrology, and the biology of various fish species.
A team of biologists and engineers used computer simulation to explore the core brain-body question of how different-sized limbs and muscles perform identical fine-motor tasks. They found that sensory feedback is crucial for controlling body movement, particularly in electric fish.
A study led by HKU marine biologist Dr Celia Schunter reveals that reef fishes are directly affected by heatwaves, but their responses vary greatly among species. The research tracked the molecular response of five species to the 2016 heatwave conditions on the Great Barrier Reef.
A recent study found that heatwaves have varying effects on different fish species, with some struggling more than others. The research tracked changes in gene expression in five coral reef fishes before, during, and after a severe marine heatwave, revealing species-specific responses to the heightened temperatures.
The study found that fish species and size affect the types and amounts of plastics ingested, with larger fish consuming more plastics. The research sheds light on how plastics enter marine ecosystems from urban watersheds and highlights the need for better understanding to reduce plastic pollution's impact.
Researchers studying coral reef fish found species-specific physiological responses to warming temperatures, influenced by heatwave intensity and duration. The study's results signal potential long-term consequences for fish fitness and ecosystem health.
A new Duke University study finds that microplastic fibers cause cellular changes in fish, including damage to gills and increased egg production in female fish. The study suggests that chemicals from the fibers may be acting as endocrine disruptors, threatening both freshwater and marine organisms.
A new study from Keck School of Medicine of USC found that children whose mothers ate fish 1-3 times a week during pregnancy had lower metabolic syndrome scores than those who ate fish rarely. Moderate fish consumption during pregnancy was associated with reduced inflammation and improved child metabolic health.
Researchers propose using preserved museum fish specimens to calculate length-weight relationships, aiding in estimating biomass and studying hard-to-reach species. This method improves data accuracy by leveraging existing specimen information.
A new study finds that sequential hermaphroditism in reef fish evolves when larger males dominate mating territories, controlling mates and resources. This theory is supported by comparative analysis of 89 species of wrasses and parrotfishes with different mating systems.
A team of researchers has shown that fish school by copying each other and changing directions randomly, rather than calculating and adapting to an average direction of the group. This new model proposes that noise-induced ordering is responsible for schooling behavior, contradicting previous theories.
Long-standing human stressors like agricultural run-off and overfishing have contributed to coral reef die-offs. Coral communities were being transformed by human activities much earlier than previously thought, according to recent studies.
A study reveals that 70% of East African reefs have depleted fish stocks, affecting food production and reef ecology. Rebuilding fish biomass is key to long-term sustainability.
A new study predicts that proposed hydropower dams in Gabon will block access to freshwater habitats suitable for marine species, impacting at least 350 fish species. The dams may cut off 60% of the most suitable habitats in the Nyanga river, representing 392 river kilometers.
A large study of nearly 30,000 adults found that eating processed meat increases the risk of cardiovascular disease and death. The study also found no significant association between unprocessed red meat consumption and risk of cardiovascular disease or death.
Sex-changing fish species can recover faster and more predictably than fixed-sex species when fishing is eliminated within Marine Protected Areas. This is because they can replace lost males with females, increasing reproduction rates.
A study reveals that effective fisheries management can increase fish stock abundance and reduce yield loss from overfishing. In regions with less developed management, high fishing pressure results in a three-fold greater harvest rate compared to well-managed areas.
After 20 years of misidentification, researchers have confirmed the presence of the chanchita in Florida waters, a South American freshwater fish that could outcompete native species for habitat and food resources. The correct identification is crucial for proper management and conservation efforts in the state's aquatic ecosystems.
A new study reveals that ocean acidification has no direct impact on the behavior of coral reef fish, contradicting previous high-profile studies. The exhaustive analysis, led by Université de Montréal researchers, found consistently normal behaviors in fish under predicted end-of-21st-century CO2 levels.
A comprehensive multi-year study challenges previous findings that ocean acidification will negatively impact coral reef fish behavior. The research found that CO2 levels expected by the end of the century have a negligible impact on fish activity levels and ability to avoid predators.
Researchers at Stanford University found that humpback whales use stealth and deception to capture fish, overcoming limitations in speed and maneuverability by timing their lunges. This innovative feeding strategy allows them to consume a large number of fish per feeding event, making it more energetically efficient than feeding on krill.
Researchers found that physical forces, including friction and stress, play a crucial role in shaping the chevron patterns in fish muscle. The team identified specific mechanisms, such as cell elongation and orientated cell rearrangements, that contribute to the formation of these patterns.
Researchers found that juvenile Coho salmon grew fastest and survived longest when exposed to natural temperature gradients and plenty of food. However, there is a catch: while food can help offset the effects of rising temperatures, it cannot completely compensate for the impacts of climate change.
Researchers found that playing healthy reef sounds through loudspeakers in dead coral patches doubled fish arrival and increased species diversity by 50%. This 'acoustic enrichment' method could help kick-start natural recovery processes on damaged coral reefs.
A study found that recreational fishing in Wisconsin's walleye lakes contributes to declining fish stocks, with overharvesting reaching 40% in some areas. The research suggests that fisheries managers should consider production rates instead of abundance alone to set more effective regulations.
A new study by the University of Plymouth explores how wild fishes behave spatially when reacting to an artificial stimulus, such as a laser. Researchers found that certain species would 'chase' the lasers, up to five metres, and that there were differences based on size and gender within species.
Research finds that prey-size plastics are abundant in fish nurseries and outnumber larvae by 7 to 1. The discovery could impact marine ecosystems as these plastics may be ingested by larger fish.
Larval fish from various ocean habitats consume plastic, affecting development and survival. Surface slicks act as nursery habitats, concentrating planktonic prey and plastics.
New research reveals that surface slicks in coastal waters of Hawai'i contain a high concentration of larval fish, as well as prey-size plastics. Larval fish ingesting these plastics may face development and survivorship impacts due to toxicity and malnutrition.
Researchers found that larval fish in ocean surface slicks ingest prey-size plastics, which could impact their development and survival. The study highlights the importance of understanding complex gradients in plankton and larval fish abundance to protect these vulnerable life-history stages.
A study found declining mercury concentrations in lake trout from Lake Michigan, likely due to domestic emissions reductions. However, changes in fish diets and growth rates due to zebra mussel invasions slowed these declines.
The Gill-Oxygen Limitation Theory explains why fish migrate poleward in response to warming waters. As water temperature increases, the amount of dissolved oxygen decreases, making it harder for fish to breathe, while also increasing their oxygen demand.
Biologists have discovered that coral reef fish take advantage of parental care to raise their own young. Genetic tests revealed that many parents were caring for mixed broods of young from different species. The study found evidence of both adoption and brood parasitism, with unrelated young fish benefiting from parental protection.
Using anesthetics to study fish colors can be misleading due to altered coloration. Researchers studying colorful patterns in small fish species found that common anesthetics affected hue, saturation, and brightness.
A University of Alaska Fairbanks study tested 297 subsistence-caught fish from Kotzebue Sound and found average mercury levels safe for unrestricted consumption. Only four individual fish exceeded the
Researchers uncover traditional fish preparation techniques employed by fisherfolk in Panama and Egypt, revealing patterns of modifications to fish skeletons comparable to those found in archaeological sites. The study provides a powerful model for identifying fish butchering and preservation methods at archaeological sites worldwide.
A study by University of Jyväskylä and Luke found that enriched rearing significantly enhances the survival of fish from bacterial infection in aquaculture. The results may advance natural disease prevention methods in aquaculture, improving post-release survival after stocking into the wild.
Researchers found that fish preserve 'DNA methylation' memories between generations, unlike humans where this is almost entirely erased. This discovery opens up new avenues for studying intergenerational memory transfer through DNA methylation.
Current fisheries management methods fail to rebuild many fish stocks with a 55% average recovery rate. Robotics-based approaches can achieve higher recovery rates and increased economic returns.
A study found that fish die-offs in Wisconsin lakes are strongly linked to heat waves and warmer surface water temperatures. By mid-century, fish kills are expected to double, and by 2100, they will quadruple.
Researchers at Chalmers University of Technology found that fatty fish provide clear protection against type 2 diabetes, but only if they are free from environmental pollutants. The study used innovative methods to analyze data and identified biomarkers in blood samples to objectively measure fish consumption.
A new statistical analysis published in the Bulletin of the Seismological Society of America has found no correlation between deep-sea fish appearances and earthquakes in Japan. Despite long-held folklore suggesting otherwise, researchers have only identified one potentially correlated event out of 336 sightings and 221 earthquakes.