THE CHINESE MITTEN CRAB 



By A. Panning, 



Hamburg, Germany 



[With nine plates] 



PREFACE 



The assumption that animals settle in new lands beyond the borders 

 of their native habitats and thus extend the range of their habitation 

 often plays an important part in zoogeography. Such assumptions 

 are very plausible in many cases, but they are usually difficult to 

 prove, because these assumed happenings took place so far back in 

 the history of the earth. Extensive studies have been made in our 

 times about animals living in regions far away from their original hab- 

 itats. Some of these animals have been intentionally transplanted by 

 man and some have been brought in unintentionally on commercial 

 carriers, as on ships, for instance. One of the very best and most 

 recent examples of this is the presence of the Chinese mitten crab in 

 the North Sea and in the Baltic countries following the opening of 

 extensive shipping between Germany and eastern Asia. This mitten 

 crab was almost unnoticed for years but during the latter part of the 

 past decade has increased enormously and has developed suddenly 

 into a serious danger to the fishing industry. The necessity of effec- 

 tively fighting these obstructive crabs has led to thorough scientific 

 investigations into all their characteristics and everything about them. 

 The lively maritime traffic between Germany and eastern Asia will 

 continue to leave many ways open for the further distribution of this 

 resistant and adaptable crustacean, and a short account of its intro- 

 duction into Europe, its distribution over Germany and neighboring 

 countries, and its characteristics and ways and habits may be of 

 general interest. 



THE MITTEN CRAB'S ORIGINAL HABITAT 



The genus Eriocheir is a native of eastern Asia and contains three 

 species. The Japanese mitten crab (Eriocheir japonicus de Haan) 

 inhabits the Japanese islands from Formosa in the south to the 

 southern point of Sakhalin in the north, also the coast of the Asiatic 



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