92 J. E. Cooper and A. L. Braswell 



indicated by the fact that in April 1984 JEC examined several bright 

 blue specimens of this species, said to be from "Thailand," that 

 were for sale as exotic novelties in a Raleigh tropical fish shop. A 

 form I male was purchased and is in the NCSM collections, C-1295.) 



Smiley and Miller (1971:221) estimated the frequency of blue 

 variants in normally non-blue P. a. acutus as 1 in 50,000. Black 

 (1975) experimentally demonstrated that blue color in this species is 

 a mutation, in which the gene controlling the chemical composition 

 of a carotenoid pigment in the exoskeleton behaves as a single 

 recessive allele, with complete penetrance of the dominant normal 

 allele. He estimated the ratio of blue to normal crayfish in the pond 

 of origin of his parental stocks at 1:5,600. Anthony D'Agostino has 

 bred cobalt blue Homarus americanus, and the F x offspring inherit 

 this coloration as a homozygous recessive trait (Porterfield 1982:38), 

 which is what Black found in P. a. acutus. 



With a nod to William of Occam, we find it considerably more 

 parsimonious to conclude that the Wayne County C. latimanus was a 

 genetically blue individual than that its abnormal color was produced 

 by diet or environmental conditions. 



In North Carolina, C. latimanus is a common, widespread 

 inhabitant of the eastern Piedmont Plateau and much of the Coastal 

 Plain. It is possible, though, that it also occurs in the Hiwassee River 

 basin of the Blue Ridge, as we discuss later. 



Cambarus (Depressicambarus) reduncus Hobbs 

 Bouchard (1978:40) gave the range of this species as "in the 

 Piedmont province from the Cape Fear River drainage in North 

 Carolina southward to the Santee River basin . . . .," and in the latest 

 American checklist Hobbs (1989:16) gave it as "Piedmont Province 

 from Orange County, North Carolina to Richland County, South 

 Carolina." Concerning the northern terminus of its range, these 

 statements almost certainly were based on specimens from the upper 

 Cape Fear basin in and around Chapel Hill, Orange County, earlier 

 reported by Hobbs (1956:66-67) and Hobbs and Peters (1977:50). 

 Although Cooper and Ashton (1985:9) had reported C. reduncus from 

 the Neuse and Tar-Pamlico basins, north of the Cape Fear, they gave 

 no particulars. The following localities extend the known range of 

 this species north into the Piedmont headwaters of these two rivers, 

 very close to the Roanoke River basin. 



NEUSE RIVER BASIN. Durham Co.— (1) Lick Crk at SR 1905, 

 10 air mi (16 air km) E Durham; 1 6 I (NCSM C-520), 27 Jan 1979, 

 A. P. Capparella. Granville Co. — (2) burrow in roadside ditch along 



