584 PROCEEDINGS OF THE NATIONAL MUSEUM vol. u? 



spawns with the male mounted on the female's back like most darters. 

 The thii'd group includes E. chlorosomum (Hay), males of which have 

 tubercles on the pelvic and anal fin rays only. Thus, on these criteria, 

 the subgenus Boleosoma is not a natm'al group. In some respects 

 the nigrum group is closer to the subgenus loa than to the stigmaeum 

 group, although E. chlorosomum is somewhat intermediate between 

 the two groups of Boleosoma. 



Cole (1957) noted that, as the spawning season for E. nigrum 

 nigrum approached, the body became blackened; the W and X 

 lateral markings became darker and appeared as diffuse blotches; 

 the dorsal saddles became less pronounced; the head and hps became 

 black; lines and spots on much of the body tended to disappear; 

 the pelvic and anal elements became heavily blackened and the 

 membranes became only slightly less blackened ; the pectoral, dorsals, 

 and caudal darkened; the pelvic spine and the first two or three rays 

 and the more ventral elements of the pectoral fin acquired whitened 

 knoblike tips. This tendency is shown to an extreme degree by one 

 of Cole's (1957) undescribed subspecies of E. nigrum, in which the 

 lower pectoral membranes became separated at the tips of the rays 

 in the breeding males and females and ended in large, fleshy, whitish 

 knobs. These knobs apparently serve to protect the tips of the rays 

 during spawning and nest defense. Winn (1958b, p. 172) reported 

 that males of E. nigrum nigrum were larger than females and had 

 larger anal, first dorsal, second dorsal, pectoral, and pelvic fins, 

 and had the first four or five spines of the first dorsal fin adorned 

 with thickened, opaque, white tips. E. n. nigrum spawns upside 

 down underneath rocks and the male subsequently defends the nest 

 (Winn, 1958a; 1958b, fig. 5). 



Breeding males of E. olmstedi also become very dark but not to so 

 extreme a degree as in E. nigrum (Cole, 1957). E. olmstedi breeds 

 in a similar manner to E. nigrum (Atz, 1940). Males of E. longi- 

 manum taken in April and June dift'er from females in having the 

 pigment pattern virtually obscured by melanophores; the fins, the 

 breast, belly, sides, and head are essentially black. The tip of the 

 pelvic fin spine is swollen into a small white bulb. There are fleshy 

 tips to the pectoral fin rays that are most conspicious on the more 

 ventral fin rays. Males are larger than females (Raney and Lachner, 

 1943). Males of E. perlongum taken on March 26 (CU 30035, Lake 

 Waccamaw) have much darker fins than the females, especially 

 the first dorsal, anal, and pelvic fins. Fleshy tips are present on 

 the distal ends of the pelvic fin elements, but these are not as promi- 

 nent as in E. nigrum or in E. olmstedi. Cole (1957) did not find 

 tubercles in any species of the nigrum group. 



