The Conversation hosts a good post by Ana Nunes about the introduction of crayfish into Africa. Marmorkrebs make a brief cameo appearance (with an incomplete name):
Another species that bears mentioning is the marbled crayfish or “Marmokrebs” (Procambarus fallax) (sic). It was introduced to Madagascar for mysterious reasons, but there may be a link with a road building project carried out by foreign contractors in 2003/2004. In 2005, biologists at the University of Antananarivo noticed it being sold in markets close to the capital.
This particular crayfish has a peculiar history: nobody knows where it comes from. It simply appeared in the German aquarium trade in about 1995. It is also the only decapod in the world known to be able to reproduce by parthenogenesis – a female is able to reproduce without being fertilised by a male. This means that a single individual is sufficient to start a whole new population. As such, this species seems very likely to pose a serious threat to freshwater biodiversity in Madagascar.
Even though it focuses on one continent, it is a very nice lay summary of the issues around crayfish introductions.
Freshwater crayfish: the forgotten invaders wreaking havoc across Africa
Pictured: Lake Naivasha, site of a Procambarus clarkii introduction. Picture from here.