About Potamonautes perlatus (H.Milne Edwards, 1837)
Potamonautes perlatus, commonly called the Cape river crab, is a species of crab belonging to the family Potamonautidae. This species is found in South Africa, especially in Cape Province. Unconfirmed reports note that it may also occur in parts of Namibia. Its primary habitat is rivers, but it is also widespread in farm dams, where it is often considered a pest because it tends to dig tunnels into earth dams. This tunneling is unlikely to cause serious damage to professionally engineered dams, but it may occasionally damage small farming earthworks. Because it is primarily a river-dwelling species, populations living in farm dams with no direct stream connection have a tendency to migrate out of the dam during rainy periods, most often at night. It is not confirmed whether this migratory behavior reduces the species’ overall population numbers, as populations in stable dams appear to persist indefinitely. Ecologically, this species is often quite important: it acts as a detritus shredder, preys on small fish and amphibians, and is a major prey source for large fish, otters, aquatic reptiles, and many other animals. It also serves as an intermediate host for a variety of parasites.
