Spawning Activities of Notropis chlorocephalus, 



Notropis chiliticus, and Hybopsis hypsinotus, 



Nest Associates of Nocomis leptocephalus 



in the Southeastern United States, 



With Comments on Nest Association 



(Cypriniformes: Cyprinidae) 



Carol E. Johnston 



Center for Biodiversity 



Illinois Natural History Survey 



607 E. Pea body Drive 



Champaign, Illinois 61820 



ABSTRACT. — Spawning activity of Notropis chlorocephalus was 

 observed in 1987 and 1988 and of Notropis chiliticus and Hybopsis 

 hypsinotus in 1988. Descriptions of spawning have not been published 

 previously for these three species. Aggregations of males of all three 

 species were observed over the nests of Nocomis leptocephalus. A 

 female N. chlorocephalus or N. chiliticus typically initiated spawning 

 by moving over the nest, where she was pursued by one to several 

 males. Spawning then occurred in N. chlorocephalus and N. chiliticus 

 when a female moved or was driven by a male (or males) to the 

 substrate; the pair vibrated and presumably released gametes. Spawning 

 often occurred in small pits (one to several) on the tops of nests; these 

 pits were constructed by male Nocomis for their own spawning. The 

 spawning act was not observed for H. hypsinotus; however, numerous 

 tuberculate males were observed holding territories over nests, and ripe 

 females were collected from the area immediately downstream of the 

 nests. Some authors have suggested that associates are attracted to the 

 nests of other species because of a lack of suitable spawning substrate 

 elsewhere in the stream. Ten artificial nests were constructed in streams 

 with active Nocomis nests and monitored for the presence of nest 

 associates. No fish were seen over the artificial nests (41 observations), 

 which indicates that the associate species are benefited by other factors 

 specific to the Nocomis nests, such as the parental care of the nest- 

 building male or the selfish-herd effect of numerous fishes spawning in 

 one place. 



Little published information on life histories exists for Notropis 

 chlorocephalus (Cope), Notropis chiliticus (Cope), or Hybopsis 

 hypsinotus (Cope). Notropis chlorocephalus and N. chiliticus, both 

 species of the subgenus Hydrophlox, occur in small, clear streams where 

 they are often abundant. The range of N. chiliticus includes the Peedee 

 drainage and the Dan River (Roanoke drainage) of North Carolina and 



Brimleyana 17:77-88, December 1991 77 



