Cia'STACEA 



2"j:; 



protect those crabs by making closed seasons aiul by si.>ecifviug size 

 limits, but the natural history <»t" this si)ecies has not be«*n adequat«'ly 

 studied. 



Crawfish — Astacus (Pacific); Cambarus (Atlantic). .Many sj»eci«'s «>f 

 these two genera inhal>it North Aiiifri< an I'rrsli watt'rs and lowlands, 

 several of them growing to (i imln's in K-ngtli. They arc extensively 

 iisid for food ill Europe and are growing in fa\<»r in soint- parts of this 

 eouiitry. The t1«*sh is delicate and sweet, like that of lobsters and crabs, 

 ami there is no good reason why they should not be much mitie widely 



Fto. 180. Female and male crawlisli. the female with eirgs 



ai)preciated and utilized. In the waters they often form the chief fo...! 

 of our game fishes, especially of the black bass. 



Crawfish are found in tlu; fresh waters of the temperate /.ones of all 

 the continents except Africa, and it is evid«Mit that they have developed 

 from a number of different marine forms. The largest crawfish in 

 the world is Astdcopsis /ninllinli, found in the small streams along 

 the north and we.st coasts of Tasmania. The.se often weigh as much 

 as 9 pounds; and if they could be safely introdtu'ed, they might give 

 us an industry for our fresh waters that would rival lobster culture. 



The land crawfishes, known as "chimney builders," dig holes in soft 

 ground, generally down to water. These are about an inch in diamett-r 

 and are surrounded by a chimney of excavated earth. This burrowing 

 habit makes them serious pests in embankments and levees. They are 

 also, in part, vegetable feeders and are often destructive to young plants 

 of field or garden. \ few Irops of carbon bisulphide in a burrow will 



