Musseling in on evolution September Evolution is a slow process through which species gradually adapt to their environments, right? Well perhaps sometimes, but not for the blue mussel. In August of , Aaren Freeman and James Byers of the University of New Hampshire announced that the blue mussel has evolved defenses against a new invasive predator in just 15 years! Compared to the million-year time scale of the fossil record, that's the blink of an eye.
Cornell Cooperative Extension
Musseling in on evolution
The first sightings of a highly invasive crab from the northwest Pacific have been reported on mainland Britain. The Asian shore crab, Hemigrapsus sanguineus, is native to the coasts of Japan, China, Taiwan, Korea and Russia and probably arrived here clinging to the hull of a ship from France. The crab is already an invasive species on the eastern coast of America and the northern coasts of France, Belgium and Holland, where it is displacing native shore crabs and destroying shellfish. The Asian shore crab would also compete with our native shore crab, Carcinus maenas, causing its population to decline. Non-native species are a growing problem throughout Europe due to increased world trade and tourism and a warmer climate. The crab is small up to 4. If you find an Asian shore crab, please report it to the MBA.
Texas Invasive Species Institute
These small crabs are identified by a square-shaped shell and three spines on each side of the carapace. Their coloration can range from orange-brown to green, or even purple! There is a distinctive banding pattern present on the legs, and the claws are speckled.
The Asian shore crab, Hemigrapsus sanguineus , a native of the western Pacific Ocean from Russia to Hong Kong and the Japanese archipelago, is also known as Japanese shore crab and Pacific crab. Atlantic coast is unknown, but it is theorized that adults or larvae were introduced via ballast water discharge from international shipping. This shore crab has a square-shaped shell with 3 spines on each side of the carapace.