Range: Eurasia; Introduced to North America and other regions of Europe Habitat: Hard surfaces in freshwater systems Size: Up to 2 inches (5cm) long Diet: Phytoplankton, zooplankton, detritus, and more Threats: Small fish, copepods, hydras, and freshwater sponges as larvae; Fish, ducks, gulls, crabs, crayfish, and more as adults Life span: Three to nine years

Transcript:

Today on Animal Fact Files we’re discussing zebra mussels. Now, these animals have a bad reputation because they’re invasive to many parts of the world and their presence in non-native ecosystems has harmed native animals by reducing food and habitat available to them. So zebra mussels can be bad news. There are plenty of other videos on this topic though, Today, we’re going to focus on the animal itself and not the unintentional destruction it has caused. Remember, zebra mussels have spread around the world because of humans, so let’s not be so quick to blame the mussels.

Zebra mussels are native to slow moving freshwater systems of Eurasia, and perhaps more specifically to lakes of southern Russian and the surrounding regions. They can be beneficial to freshwater systems because, like oysters, a large colony can filter huge amounts of plankton from the water which makes the water more clear thus allowing more light to penetrate to aquatic plants which then provide food and habitat to other organisms. It’s the circle of life in action!

Zebra mussel adults are sessile, meaning they remain in a single place until they die. That doesn’t technically mean they can’t move, because they’re able to settle onto other animals that are able to move around, like crabs, but for the most part these bivalves prefer hard surfaces like rocks. They stick to these surfaces by releasing threads that hold them in place.

Though they have the name “Zebra mussel” for their striped appearance, these mollusks also come with no stripes and just a single color. One way to tell them apart from other mussels is to see if they can stand up on their own. The bottom of a zebra mussel’s shell is so flat that it can stand on a smooth surface without rolling! In size, adults max out at 2 inches (5cm) in length.

These bivalves start out life as an egg. Males and females, who may begin reproducing after their first year in optimal temperatures, release sperm and eggs into the water column to be fertilized externally. The eggs hatch about three to five days later into larvae. They’ll live as larvae for about a month before settling onto a surface. This is a hazardous time for the zebra mussel as the larvae are easy targets to small fish, copepods, hydras, and freshwater sponges.

Though they don’t have eyes, if adults are disturbed or pick up chemical cues that someone unpleasant is nearby, they’ll close their shells. Predators to zebra mussel adults include fish with strong enough beaks to break the mussel’s shell like bream and carp as well as ducks, gulls, crabs, crayfish, and more. If they can avoid these predators, they can live anywhere from three to nine years of age.

For more facts on zebra mussels, check out the links below. Give a thumbs up if you learned something new today. Thank you to our Patrons SpikeSpiegel93, Dad, and everyone else for their support of this channel! Thank you to marvelous for today’s request! And thank you for watching Animal Fact Files!