NO. 3544 SUBSPECIES OF CAMBARUS LONGULTJS — JAMES 21 



accounts, frequent quiet pools, springs, or mountain "feeder brooks." 

 Stream beds are typically of rock-strewn sand or gravel and relatively 

 free of silt deposits. 



Most specimens of C. I. longulus were taken from riffle areas in the 

 lower mountain or upper piedmont streams. The water, clear or 

 comparatively so, ranges from 2°-24° C, The current, over riffles, 

 has been recorded as moderate to rapid. In streams with both pool 

 and riffle areas, C. I. longulus was found only in the riffles. Stream 

 beds of sand or gravel and strewn with rocks are characteristic of 

 the habitats in which this crayfish usuaUy is found. The size of the 

 stream seems to have little, if any, influence on whether or not C. I. 

 longulus frequents it. 



The subspecies C. I. chasmodactylus varies from the typical sub- 

 species in seeming to prefer larger, often turbulent streams. It is 

 found abundantly in Reed Creek, Wythe County, Va. ; typicaUy, this 

 animal, as described by Ortmann (1931, p. 119) lives "in the usual 

 way under stones in flowing water [italics mine]." 



Of the three subspecies, C. longulus longirostris is by far the least 

 ecologicaUy restricted. A ciu-sory examination of the wide distri- 

 bution (maps 1, 2) should suggest the apparent adaptability of this 

 crayfish to the larger streams and rivers as weU as to the smaller 

 tributaries. In McMinn County, Tenn., it was found to be numerous 

 in beds of Nasturtium sp. in a spring run; nearby, occasional animals 

 were found in debris littering a stream bed of silt and sand, where there 

 were but few rocks. 



Serological Affinities 



Johnson, in 1957 and again in 1959, using agar diffusion and tube 

 precipitation techniques, serologically compared, among others, the 

 three subspecies of Cambarus longulus (Cambarus sp. = C. I. chasmo- 

 dactylus). Antigen (crayfish serum) and antibody (rabbit anti- 

 crayfish serum) reactions, when compared (1957, p. 182; 1959, p. 183), 

 indicate the close affinities of the three. 



Summaries of Ratios 



The tabulation below summarizes the collective quantitative data 

 (figures of each column represent ratios of measurements of selected 

 characters; upper row, minimum ratio; middle, maximum; lower, 

 average) : 



