Articles tagged with Fish
The rapid decline of Diporeia due to quagga mussel invasion in Lake Michigan has significantly impacted the lake's food web. Fish populations are facing reduced food options as quagga mussels displace more energy-rich prey sources.
Stanford researchers developed a computer simulation to predict the movement of fish farm waste in the ocean. The model, called SUNTANS, reveals that wastes can travel greater distances and in higher concentrations than previously assumed.
Scientists have developed a new computer model predicting climate-driven shifts in commercially important fish species. The study suggests that most fish will migrate towards the Pole, with devastating consequences for developing countries' fishing industries.
Long-term research reveals a quarter-century of data on penguin numbers, showing a decline of over 20 percent in the last 22 years. Penguins are struggling with food scarcity, leading them to nest outside protected areas where they fall prey to predators.
A new species of fish from tropical South America has been discovered, confirming suspected roots to the loricariid catfish family tree. The species, Lithogenes wahari, shares traits with both the Loricariidae and Astroblepidae families, including bony armor and a grasping pelvic fin.
A study by Uppsala University researchers found that females' promiscuity leads to males producing faster and larger sperms. The competition among sperms influences various characteristics, including size and speed.
A study suggests that aquaculture can be a sustainable way to meet growing demand for seafood, reducing pressure on wild stocks and enhancing depleted ones. Improved management techniques have diminished some harmful effects of the practice, but more comprehensive information is needed to guide its growth.
A review of salmonids reveals that captive breeding can rapidly lead to genetic diversity loss, hindering the ability of fish to adapt in the wild. The study highlights the need for more data and alternatives to captive breeding, such as live freezing or population relocation, to conserve biodiversity.
The Smithsonian Tropical Research Institute has launched an online information system to identify and generate maps for 1,287 tropical eastern Pacific shore fish species. The system allows users to search by common name, location, shape, and color, and provides detailed information on each species.
Stickleback fish follow a consensus decision-making process to choose their leader, prioritizing size, fatness, and health. As group size increases, accuracy improves, but occasional errors occur due to submission to peers and cascades of incorrect decisions.
The study uses electronic tracking to monitor the movements of Atlantic bluefin tuna, revealing new insights into their migratory patterns, physiology, and population structure. The data show that fish from different populations forage together on common grounds before moving to distinct spawning areas.
A new study found that salmon smolts survive at similar rates of 70-80% in both the Columbia and Fraser rivers, with differences attributed to stressors such as dams, water temperature, and contaminants. The research used acoustic and transponder tags to track survival rates over a four-year period.
A genetic study of an Antarctic 'antifreeze fish' has revealed a small set of genes that dominate the transcriptional process, enabling it to survive in cold, oxygen-rich environments. The study found high expression of proteins responding to environmental stress, such as heat shock proteins and ubiquitins.
A Caribbean experiment shows that maintaining proper balance of plant-eating fishes may be key to restoring coral reefs, which are declining dramatically worldwide. Research found significant recovery in sections of coral reefs on which fish of two complementary species were caged.
Small-scale fisheries, which employ over 12 million people worldwide, are being disproportionately harmed by eco-labelling initiatives and fuel subsidies. As a result, many small-scale fishers are unable to compete in the market and struggle to survive due to unfair advantages given to large-scale industrial fleets.
The New Zealand mud snail is outcompeting native species, altering food chains and ecosystems in the Great Lakes. Research suggests the snails can survive being frozen for short periods, making control difficult.
No-take marine reserves can help prevent crown-of-thorns starfish outbreaks, reducing their impact on coral cover. The frequency of outbreaks is lower in protected zones, suggesting a potential benefit of fishing bans.
Researchers mapped the developing brain cells in midshipman fish larvae and compared them to other species to find that the neural network behind sound production is conserved across vertebrates. This finding puts human speech and social communications in evolutionary context, providing a framework for studying social behavior.
The study found that physical changes caused by damming have a disproportionate adverse effect on native fish, which are more vulnerable due to their life history differences. The researchers suggest recreating the high-flow, sediment-rich waters of the Colorado River to reverse the decline in native species.
A 50-year analysis of Narragansett Bay fish-trawl surveys reveals a shift from vertebrate to invertebrate species and from benthic to pelagic species composition. The study attributes this change primarily to global warming, with smaller, warm-water species increasing while larger, cool-water species declining.
A new species of catfish, Rhinodoras gallagheri, has been named in honor of Frank Gallagher, a retired Academy of Natural Sciences mailroom supervisor. The Orinoco thicklip catfish was discovered in the Academy's collection and is found in the Orinoco basin in Venezuela and Colombia.
Fishing on drifting fish aggregation devices (FADs) poses a significant threat to the survival of tropical tuna, especially juveniles. Studies have shown that FAD-associated tuna feed less well and have lower plumpness than those caught from free schools.
The NOAA National Marine Fisheries Service uses otoliths, scales, and vertebra to age tens of thousands of samples each year. The aging team provides critical data for stock assessments needed to manage the nation's fishery resources in the Northwest Atlantic Ocean.
Research found that fishing on FADs resulted in tuna with empty stomachs, lower plumpness, and altered migration patterns. The practice may lead to ecological traps for young fish, which could impact the entire life cycle of these species.
A new report by the Ecological Society of America finds that restoring fish populations in the Great Lakes leads to a shift in herring gull diet, with birds opting for terrestrial food instead. This change may have severe consequences for other species, such as terns, which are more closely tied to aquatic environments.
A study by Ashley J. W. Ward and colleagues found that groups of fish only follow leaders when a threshold number of fellow group members perform a particular behaviour, reducing the risk of non-adaptive following. This quorum response is also relevant to human decision-making.
Researchers create computer simulation that accurately predicts fish species diversity in river basins, identifying 'hot spots' for conservation. The model uses rainfall measurements and river network structure to forecast species abundance.
Scientists discovered an Antarctic fish species that enters a dormant state similar to hibernation to conserve energy during the long winter. The study showed that the fish reduces its metabolic rate even when seawater temperature doesn't decrease, suggesting alternative drivers for this behavior.
Scientists at UC-Santa Barbara found that fish larvae that endure long and rough ocean journeys arrive on reefs in good condition and go on to thrive. In contrast, locally produced young have a harder time surviving and only do well if they are in excellent condition.
The Bering Sea's rich food web could fray as algae adapt to greenhouse conditions, affecting top predators like pollock and hake. A shift away from diatoms towards smaller phytoplankton could undermine the biological pump, making the ocean less able to soak up atmospheric carbon dioxide.
A gene in male cichlid fish produces yellow pigment cells on oval spots, attracting female fish. The fish engage in an exotic oral mating behavior, where males deposit sperm in the females' mouths after she picks up eggs.
A rare albino ratfish with a crystalline layer on its skin was caught off Whidbey Island, marking the first time such a specimen has been seen by both experts and scientists. The fish's unusual appearance is due to a gene mutation that prevents it from producing melanin.
A new DNA analysis revealed that five of nine relic populations of what biologists believed to be greenback cutthroat trout are actually Colorado River cutthroat trout. This study highlights the need for accurate identification and management strategies to conserve the species.
Hypoxia caused by low oxygen levels in coastal waters impairs fish reproduction by disrupting their hormones. Laboratory studies found that hypoxia decreases serotonin levels in the brain, leading to endocrine disruption.
Two closely related species of East African cichlid fishes evolved divergent immune gene adaptations, explaining their reproductive isolation. These differences in MHC genes influenced mating behavior through olfactory communication.
Researchers discovered that African electric fish engage in 'electric duets' during aquatic courtship, using specific signals and motor displays. The study provides insight into the electrical and behavioral patterns of mating in these fish.
Researchers have developed protocols to maximize post-release survival of commonly caught species, including luderick and Murray cod. Key recommendations include cutting lines on fish that swallow hooks, resulting in improved mortality rates for some species.
Researchers have pioneered a new way to study fish populations by 'tagging' adult fish with a harmless isotope, enabling them to understand the extent to which young fish return to their 'home' area or go off to interbreed. The findings reveal that around 60% of juvenile clownfish returned to the home reef, while 40% came from distant ...
Researchers from Harvard University found that ancient aquatic amphibians developed the ability to feed on land before transitioning to terrestrial life. Analysis of skull bones reveals that these extinct animals captured prey by biting or sucking it into their mouth, with one key species showing signs of biting behavior.
Researchers are developing alternative culture methods to reduce the use of live fish in safety testing, reducing animal experimentation. Dr Richard Handy's perfusion method allows for the controlled exposure of fish organs to toxins, providing insights into toxicity and organ function.
A new species of snapper, Lutjanus alexandrei, has been discovered in the Abrolhos region of Brazil's South Atlantic Ocean. The species was previously mistaken for a dog snapper and was found to have distinct markings and color.
Commercially prized deep-sea fish are severely threatened by over-fishing and low reproductive success due to long lifespans, while technological advances have made targeting them easier.
Cornell researchers are developing a new genetic-based test to detect the deadly viral hemorrhagic septicemia virus (VHSV) in fish. The new technique, which can identify the virus in 24 hours, is set to be validated by the end of 2007 and could become the standard test for detecting this disease.
Researchers studying sedimentary records of dinoflagellates in the San Francisco area and along the western coast of North America predict an increase in toxic blooms. This change is linked to rising water temperatures, which will impact marine life and fisheries.
Researchers found females mature earlier when shown males with long 'swords', while young males delayed maturity to avoid competition. This is the first evidence of a species adjusting sexual maturation based on visual cues.
Researchers found that individuals preferred mating with unfamiliar close kin rather than non-kin due to parental cooperation. This led to more cooperative and resource-invested parenting among related parents compared to non-related ones.
The US shortnose sturgeon population has increased by over 400 percent in the Hudson River since the 1970s, marking a rare recovery of an endangered species. The study suggests that protection and conservation efforts can lead to successful recoveries, even in areas with high human activity.
A new study by Oregon State University and the EPA found that over 600 rivers in the western US have widespread mercury contamination in fish. Piscivorous fish like bass and walleye show significantly higher levels of mercury than non-piscivore species like trout.
Marine scientists discovered that baby fish can find their way back to their home coral reef by using their sense of smell, braving strong currents and predators. This unique ability has major implications for how reefs are managed and drives evolution on the Reef.
Research finds that commercial fishing causes significant variability in exploited fish populations, leaving them vulnerable to collapse. The study suggests that managing fish stocks must account for this increased variability to ensure their long-term sustainability.
A comprehensive analysis of fish consumption found that moderate intake reduces risk of coronary heart disease by 36% and total mortality by 17%. The benefits of omega-3 fatty acids from seafood also improve early brain development in infants, particularly when consumed by pregnant or nursing mothers.
A review of studies found that moderate fish consumption reduces coronary death by 36% and death rate by 17%. The study suggests that adequate consumption of other seafood is essential to minimize methylmercury exposure and ensure DHA intake.
Researchers studied environmental changes on fish appearance, finding restricted food and temperature shifts can dramatically alter morphology. The study has implications for conserving species, suggesting that habitat preservation is crucial to maintaining unique characteristics.
Researchers found that removing just one important species in a freshwater ecosystem can seriously disrupt its functioning. The study, led by Brad Taylor, showed that the loss of the flannelmouth characin had a significant impact on carbon transport and availability in a river ecosystem.
A study by Lessios and Robertson confirms close relationships between reef fish populations on both sides of the Pacific barrier, with gene flow occurring in both directions. The researchers rule out major changes in currents or geological events as barriers to population separation.
The survey found a diverse range of life, including new fish species, in Malagasy waters. The region's coral diversity is one of the richest in the Indian Ocean, making it a high conservation priority.
Researchers have discovered electric fish in Africa with the same DNA but different electric signals and appearances, sparking hope that they are on the verge of forming two separate species. The findings provide a rare example of sympatric speciation, where animals from the same geographic location diverge into distinct groups.
In Lake Victoria cichlid fish, females choose brightly coloured males for good reasons: fewer parasites and better health. The colour preference leads to speciation as only the brightest red and blue fish survive, eventually forming two separate species.
The Tiktaalik fossil exhibits a mix of fish-like and tetrapod features, bridging the gap between these two groups. The discovery supports the idea that evolution from water to land occurred gradually in shallow waters.
The newly found Tiktaalik species blurs the boundary between fish and land-living animals through its anatomy and lifestyle. The discovery provides critical early phase insights into the evolution of all limbed animals, including humans.