78 Carol E. Johnston 



Virginia (Gilbert and Burgess 1980a). Notropis chlorocephalus is endemic 

 to the Catawba River (Santee drainage) of North and South Carolina 

 (Gilbert and Burgess 1980b). Hybopsis hypsinotus inhabits small to 

 medium-sized rivers in the Peedee and Santee river drainages of North 

 and South Carolina and Virginia and is not abundant (Jenkins and 

 Lachner 1980). 



During a study of nest association among North American minnows, 

 1 observed spawning in N. chlorocephalus and N. chiliticus. Spawning 

 activities, but not the spawning act, were observed in H. hypsinotus. 

 Spawning behavior has not been described previously for these three 

 species, all of which spawn in association with Nocomis leptocephalus 

 (Girard). 



Nest association, the habit of spawning over the nest of another 

 species, is widespread among minnows of the eastern United States 

 (Table 1). The strategy is less common among other North American 

 fishes, and has been described for only three species, including longnose 

 gar, Lepisosteus osseus (L.) (Goff 1984); lake chubsucker, Erimyzon 

 sucetta (Lacepede) (Carr 1942); and creek chubsucker, Erimyzon 

 oblongus (Mitchill) (Page and Johnston 1989). Ten species of minnows 

 are known to spawn in the nests of sunfishes or basses (Latta 1958, 

 Kramer and Smith 1960, Hunter and Wisby 1961, Snelson 1972, Chew 

 1974, Pflieger 1975); the other minnows that spawn as nest associates 

 spawn over nests constructed by other minnows, particularly species of 

 Nocomis. The nests and parental care of sunfishes and basses differ 

 from the nests and parental care of nest-building minnows. The nests of 

 sunfishes and basses are saucer-shaped depressions built in a variety of 

 substrates. Eggs laid in the nests of sunfishes or basses receive direct 

 parental care from hosts, which remain with the young until hatching, 

 in the form of fanning of the eggs and predator defense. The nests of 

 minnows range from simple pits where the eggs are not covered (e.g. 

 Campostoma and Luxilus) to large gravel mounds where eggs are 

 covered by the male after spawning (e.g. Nocomis). The parental care 

 offered by minnow hosts includes predator defense, but minnow hosts 

 may remain over nests only as long as spawning opportunities exist. 



Although nest association has been known for many years, few in- 

 depth studies have been conducted, and most of the reports of nest 

 association have been little more than accounts of the species involved. 

 The occurrence of nest association raises important ecological, 

 evolutionary, and behavioral questions. Are associates attracted to nests 

 alone, which may provide the best available spawning substrate in the 

 habitat, or are they attracted to some other factor associated with nests, 

 such as the parental care offered by the host? What are the costs and 

 benefits of nest association to the associates and to the hosts? Is the 



