Red Swamp Crayfish

Red Swamp Crayfish - Procambarus clarkii

This decapod crustacean, originally from America, has been introduced into fish-farms for alimentary purposes in almost all contiinents. It was imported to the Wetlands of Northern Tuscany in the 90's, and in some places it is now abundant.

The species must not be confused with the autochthonous local Crayfish (Austropotamobius pallipes), which now only lives in a few hill streams with clear, well oxygenated water.

The Red Swamp Crayfish has a high capacity to spread and can adapt to various types of habitats, including those poor in oxygen.

It can also tolerate pollution levels that would kill even the hardiest of fish and can resist agricultural doses of fungicides and herbicides. It is considered to be a pest for the fish fauna, both because its feeds directly on the eggs of fishes and amphibians as well as on tadpoles, and because it competes with the local fauna for food resources (snails, insects and other aquatic invertebrates).

Moreover, since the Red Swamp Crayfish often feeds on water plants, the combined action of this crayfish and the Nutria can have a devastating effect on some species, like water-lilies.

Luckily, many water birds have quickly learnt that the Red Swamp Cray can be a tasty and easy meal: in the Fucecchio Marshes, for example, the herons that breed in the heronry whilst not exterminating them completely, do exert some control over this American invader.