Cape mountain zebra
The Cape mountain zebra differs slightly from the Hartmann's subspecies, being stockier and having longer ears and a larger dewlap. Adults have a shoulder height of 116 to 128  cm, making them the most lightly built subspecies of zebra. There is slight sexual dimorphism with mares having a mass of around 234  kg and stallions weighing around 250–260  kg.
Zebra mussel
The vast majority of the organisms that are natural enemies in Europe are not present in North America. Ecologically similar species do exist, but these species are unlikely to be able to eliminate those mussels already established and will have a limited role in their control.
Crayfish could have a significant impact on the densities of 1- to 5-mm-long zebra mussels. An adult crayfish consumes around 105 zebra mussels every day, or about 6000 mussels in a season. Predation rates are significantly reduced at lower water temperatures.
Fish do not seem to limit the densities of zebra mussels in European lakes. Smallmouth bass are a predator in the zebra mussels' adopted North American Great Lakes habitat.