Bloody-red Mysids are small shrimp like animals, native to eastern Europe and western Asia. They spread across Europe through rivers and in boat ballast. They can be transported between waterways by birds, boats, or fishermen. They are tolerant of a broad range of temperatures and salinities so are good invaders. They form large colonies which have negative impacts on the physiochemical environment of freshwater habitats (from inputs of fecal pellets) and change algal growth. They are omnivorous so their influence spans across trophic levels. They have been found in the River Thame in Shabbington.