Zebr Mussels a + Qu Agga Adult mussels usually grow to the size of a quarter. Offspring are microscopic, meaning you can't see them without a microscope. They look like the letter 'D' and tend to have stripes like a zebra. Boaters who do not clean their boats well can bring mussels from one water to another. Mussels can attach to boats and live out of water for up to one month. Once mussels reach a new water they start to reproduce. 6 6 Zebra and quagga mussels grow hairlike threads called byssal threads. These allow them to attach to hard surfaces under the water, including hulls of boats. This is one of the main ways they are spread around. One adult mussel can produce 1 million babies every year! New zelan mudsnails mudsnaIls They grow as big as your pinky fingernail and are shaped like an ice cream cone with 4-5 swirls. Mudsnails can hide in mud, boots, waders and fishing gear. They spread when people use dirty gear in different water bodies. They reproduce by creating copies of themselves, which is called cloning. This means one snail can start a new population - 300,000 mudsnails can live in a 3-foot square! Key! Size & identifying characteristics How they spread Villainous characteristics A D Aland inv ader info