Lake Maxinkuckee, Physical and Biological Survey 83 



THE CRAWFISHES 



By William Perry Hay, Head of the Department of Biology 

 and Chemistry, Washington, D. C, High Schools 



Crawfishes are quite common in Lake Maxinkuckee and in Lost 

 Lake; on the land about the lakes they are less frequent. The 

 truly aquatic species are found chiefly in the shallower depths, 

 hiding under rocks, sticks, and among Chara and other aquatic 

 vegetation. But even at their best, not as many will be taken in 

 the seine as will be secured in similar collecting in sluggish streams. 

 The greatest number taken in one haul of the seine in Lake Maxin- 

 kuckee was twenty-two. 



In the collections turned over to me for identification and study, 

 four species are represented, namely : Cambarus blandingi acutus, 

 C. dio genes, C. propin quits, and C. immunis spinirostris ; or, using 

 English names instead of Latin combinations, we may designate 

 these four species as the Pond Crawfish, the Solitary Crawfish, the 

 Gray Rock Crawfish, and the Rock Crawfish respectively. Of 

 these, the first three have long been known to occur in northern 

 Indiana, but C. immunis spinirostris has not heretofore been known 

 north of Terre Haute. One or two other species probably occur 

 in the Maxinkuckee region. C. argillicola Faxon, has been re- 

 ported from several localities north, east and south of Lake Maxin- 

 kuckee, and C. rvsticus Hagen, has been taken near Mt. Etna, 

 Huntington Co., Ind. 



Beyond doubt, the crawfish fauna of this lake, or of any other, 

 will repay careful study. The habits and economic importance 

 of these animals are only poorly known, but it must be that, as a 

 source of food supply for other animals, or as scavengers, they fill 

 a field of usefulness. 



As the present account is for the general public rather than 

 for the zoologist, it will be unnecessary to give more concerning 

 the structural characters of these animals than is absolutely re- 

 quired for their recognition. The male crawfish may be distin- 

 guished from the female by the presence of two pairs of rigid 

 appendages which are attached to the first two joints of the 

 abdomen or tail, and which, projecting nearly straight forward, 

 lie in a sort of groove between the basis of the walking legs. 

 In the female the abdomen is broader than in the male, and the 

 appendages of the first two joints are slender and flexible like 

 those which follow. The rostrum is the beak-like projection of the 

 shell (or carapace) above the eyes. 



