All articles tagged with #crabs
New research shows that true crabs acquired their iconic sideways walk in a single ancestral event around 200 million years ago, a shift that likely gave them a defensive edge and spurred their broad diversification; some species later evolved to move forwards, but this came from the sideways lineage rather than a repeated, independent origin.
Researchers find that true crabs acquired their distinctive sideways gait from a single ancestral event about 200 million years ago, likely aiding predator avoidance and rapid diversification, while crab-like body forms (carcinization) evolved repeatedly in other decapods; the study notes limitations such as using one specimen per species and questions about the classification boundary.
Around 15,000 crabs worth about €60,000 spilled from a lorry that tipped into a ditch near Carrickmaquigley in Redcastle, Inishowen, County Donegal. The road was closed for 18 hours as a salvage team of about 10 recovered and refrigerated the crustaceans, saving roughly 95% of the cargo and reloading it for shipment to Portugal, where the seafood was headed for shops and restaurants (along with some lobsters and oysters).
Scientists have found that crab-like bodies have evolved independently at least five times in crustaceans, driven by similar environmental pressures and internal anatomical changes, a phenomenon known as carcinization, which involves predictable morphological adaptations across different lineages.
Scientists from the Schmidt Ocean Institute were astonished when a crab appeared to conjure and steal a fish from behind a coral, revealing surprising behavior in deep-sea marine life.
Scientists have discovered that the Parasesarma eumolpe crab in Southeast Asian mangroves emits bioluminescent light from its forehead, primarily for communication and possibly for mate selection and dominance, with the glow originating from diet-derived pigments and enhanced by specialized facial structures.
Scientists from the University of Gothenburg have discovered that crabs can feel pain, prompting calls for a ban on boiling them alive. The study used brain scans to show that crabs process pain similarly to humans, suggesting that crustaceans like crabs, lobsters, and shrimp experience pain. Researchers advocate for humane methods such as electro-stunning to kill crabs, as current EU laws do not protect crustaceans from painful deaths. The findings highlight the need for updated animal welfare legislation to include these animals.
Scientists have discovered a new hydrothermal vent in the Galápagos Islands with the help of crabs. Following a chemical anomaly, researchers used a remotely operated vehicle to analyze the sea floor and found a dense population of squat lobsters, which led them to the vent. The vent, located between the Cocos and Nazca tectonic plates, spans an area of 98,800 square feet and is home to crabs, tube worms, clams, and mussels. Hydrothermal vents are cracks in the sea floor that release heated water from the Earth's magma chambers, creating a hostile environment where only certain species can survive.
A new study has found that true crabs (Brachyura) have evolved to migrate from marine to land habitats between seven and 17 times over the past 100 million years. Some crabs even returned to the sea from land on two or three occasions. Most crabs are only able to survive in semi-terrestrial habitats, with land-based crabs concentrated in one species-rich group. The findings suggest that true crabs emerged about 45 million years earlier than previously estimated, dating back to the mid-Triassic period.
A new study reveals that true crabs (Brachyura) have left the marine environment multiple times, with around 17 independent transitions to land and freshwater over the past 100 million years. The research, spanning almost 20 years, found that true crabs are older than previously estimated, dating back to the Middle Triassic. The study provides insights into convergent evolution and the adaptation of organisms from water to land, shedding light on the early processes of adaptation to new environments. The researchers also discovered evidence of crabs returning to fully marine life at least 2 to 3 times.
Evolutionary trend known as carcinization has led to various species independently evolving crab-like forms. Convergent evolution has resulted in similar features evolving in species from different periods or regions, despite lacking a common ancestor with those features. The advantage of the crab shape includes improved walking, burrowing, and climbing abilities, as well as reduced vulnerability to predators.
The evolution of crabs has resulted in the development and loss of crab-like features at least five times in the past 250 million years, a phenomenon known as carcinization. The reasons for this repeated evolution of the crab-like body plan remain a mystery, but studying crabs provides an opportunity to understand convergent evolution and predict the shapes that evolution might make based on environmental factors and genetic cues. Taxonomists are steadily piecing together what makes a crab, a crab, and resolving the multiple origins and losses of crab body forms through time.
The crab-like body plan has evolved at least five separate times among decapod crustaceans, a group that includes crabs, lobsters and shrimp. Scientists don't know for sure why animals keep evolving into crab-like forms, but they have lots of ideas. The crab-like body plan has emerged many times among very closely related animals, which means that evolution is flexible and dynamic. The fact that the trait is advantageous for the species is a sign that it sticks around through generations, which is the basic principle of natural selection.
The crab-like body plan has evolved at least five separate times among decapod crustaceans, a group that includes crabs, lobsters and shrimp. This phenomenon is called carcinization, an example of convergent evolution. Scientists have many ideas but are not sure why animals keep evolving into crab-like forms. The crab-like body plan has emerged many times among very closely related animals, indicating that evolution is flexible and dynamic. The crab body plan might leave more flexibility for animals to evolve specialized roles for their legs beyond walking, allowing crabs to easily adapt to new habitats.