This invasive bivalve is typically 2-5cm in length, often with zig-zag brown stripes, though can be solid brown. Adults attach to hard substrata such as rocks, wood, man-made piping and can smother native mussels.

It has a high filtering capacity and grows in dense populations so can significantly reduce native biodiversity and alter whole freshwater ecosystems. It is also a nuisance and economic problem when growing water treatment pipes.

Zebra Mussels are very similar but have a flattened bottom and can sit upright on a flat surface, whereas Quagga Mussels have a rounded, asymmetrical edge and will tip over on their side.

Lakes, rivers and estuarine habitats. 

All year - often empty shells can be found at the water's edge.

Limited distribution but spreading.

Locally abundant and common at Rutland Water.

Non-native invasive species portal