Nest Associates of Nocomis leptocephalus 83 



10 to 13 and from 24 to 27 May 1988 on each active nest at two sites in 

 the Catawba River drainage and on 26 May in the Fisher River.) In 

 61% of these observations (lasting from 15 minutes to 2 hours), more 

 than one male N. leptocephalus was present over the nest. In seven 

 observations, one male was over the nest; in six, two; in three, three; 

 and in two, four. Males were never observed actively driving nest 

 associates from the nest, but they did drive away such potential egg 

 predators as suckers. 



Physical measurements were taken for 1 1 active nests. The mean 

 length of the nests was 69.0 cm (SD = 21.3); mean width was 71.5 cm 

 (SD = 16.4 cm); and mean height was 15.0 cm (SD = 4.5 cm). Mean 

 surface flow was 22.9 cm/ sec. (SD =10.1 cm). Mean water depth was 42.5 

 cm (SD = 16.2 cm), and the mean distance from the nest top to the 

 water surface was 28.1 cm (SD = 16.3). 



Ten artificial nests were constructed near active N. leptocephalus 

 nests in similar physical conditions. Each of the artificial nests was 

 checked over a period of 4 to 7 days, a cumulative total of 41 checks for 

 the 10 nests, and fish were never observed over them, except incidentally. 

 No eggs were found in these nests. On all days when artificial nests were 

 checked, spawning activity was occurring elsewhere in the stream. 



DISCUSSION 



Spawning behavior of N. chlorocephalus and N. chiliticus is similar 

 to that of Notropis (Hydrophlox) rubricroceus (Cope) (Outten 1958). 

 Spawning aggregations of Notropis (Hydrophlox) lutipinnis (Jordan 

 and Brayton) have been described by McAuliffe and Bennett (1981) and 

 are similar to those formed by other nest associates. Because virtually 

 nothing is known about the spawning behavior of Hybopsis (s. str.), the 

 suggestion that H. hypsinotus is a nest associate is particularly 

 significant. Reighard (1943) found more than one male Nocomis 

 micropogon (Cope) working on, or stationed over, nests in 47% of his 

 observations (n = 15). These extra males were never observed spawning, 

 and Reighard suspected that their contribution to nest building was 

 negligible. More than one male N. leptocephalus was observed over 

 nests in 61% of my observations, indicating that, at least in N. 

 leptocephalus, the typical situation may be that more than one male 

 may participate in nest construction and spawning. These observations 

 suggest species differences in social structure during the spawning season. 

 Further study may reveal differences in spawning behavior among 

 species of Nocomis. 



Spawning aggregations of nest associates did not form over the 

 artificial nests built in this study, as would be expected if nest structure 

 or substrate was the most important factor involved in nest association. 



