90 Stephen J. Walsh and Brooks M. Burr 



may result from reproductive isolation from more typical L. aepyptera. 



Sexual differences in body proportions (Table 2) coincide reasona- 

 bly well with those reported by other workers. Males have a greater disc 

 length and second dorsal fin height than females, as noted by Rohde et 

 al. (1976) and Vladykov et al. (1975). We confirm the observations of 

 Vladykov et al. that males have a relatively longer tail and shorter trunk 

 than females. Rohde et al. found that tail length increased with age in 

 males and decreased in females. Males also have a greater prebranchial 

 length. Kentucky specimens are substantially longer (mean TL, both 

 sexes) than those reported by most other authors, especially in Atlantic 

 Coast populations where a much shorter maximum and mean TL was 

 found (Rohde et al. 1976). The mean length of the male genital papilla 

 was 4.4 mm (R = 2.4 - 7.5, N = 57). Rohde et al. found a mean papilla 

 length of 4.8 mm for 10 males from Delaware. 



Breeding coloration in L. aepyptera has not been adequately des- 

 cribed. Nest-building individuals from Peter Creek, Barren County, 

 Kentucky, were in full nuptial color orr 18 March 1980. Both sexes were 

 mottled gray-brown on the dorsum and had light silvery-yellow venters. 

 Black horizontal bands were present on the sides, through the eye and at 

 the base of the first dorsal fin. Each dorsal fin had a black, speckled 

 marginal band that was widest around the longest fin rays. A gold band 

 extended through the base of the caudal fin and the center of each dor- 

 sal fin. The posterior margin of the caudal fin was darkly pigmented. 



Aspects of Life History 



Terrapin Creek is a clear, low-to-moderate-gradient tributary of 

 Obion River. The stream consists of alternating shallow riffles and 

 deeper pools, with a substratum of sand and gravel. In most areas the 

 stream is 2 to 5 m wide and 0.2 to 1.0 m deep during normal water 

 levels, and is bordered by deciduous forest throughout most of its 

 course. Ammocoetes were generally found in mud banks along raceways 

 and in pools with a moderate current. Transformers and neotenic indi- 

 viduals were generally found in debris-ridden riffles and raceways. 



Between 22 February and 4 June 1980 we sampled a backwater 

 slough of Terrapin Creek, 0.8 km south of Bell City along Hwy. 94. The 

 slough is in a wooded area, has been inundated through beaver activity, 

 and is fed by runoff and seepage. Thick mats of watercress and other 

 aquatic macrophytes were abundant in the channels and pools. A pool 

 2.5 m wide and 1.5 m deep, with considerable mud and silt deposits, 

 yielded large numbers of ammocoetes. Species taken with L. aepyptera 

 in this beaver slough are indicated by asterisks in Table 3. 



Because of the paucity of specimens for most months, only ammo- 

 coetes from the 4 June 1980 collection were used for the length- 

 frequency analysis (Fig. 4). At least five, and possibly six, age clases are 



