A small, but pernicious mollusk -- the cockroach of the underwater world to lake managers -- has made an unwelcome appearance at two Tulsa-area lakes. Zebra mussels, a non-native, invasive species ...

Mollusks, from land snails and slugs to oysters and mussels in the sea, have a few things in common. They have a head. They have a soft middle part that holds their organs. Then, some have a muscle ...