Darter Spawning Behavior 141 



seine and contained 42 eggs. E. barbouri is the last of the ten 

 taxonomically described species of Catonotus to be confirmed as an 

 egg-clustering species. 



Etheostoma (Nothonotus) aquali. — The subgenus Nothonotus of 

 Etheostoma is the only subgenus of darters in which some species bury 

 their eggs and others clump them (Table 1). From a study conducted in 

 Pennsylvania, Raney and Lachner (1939) first reported the egg- 

 deposition site of Etheostoma maculatum Kirtland. In Tennessee, Stiles 

 (1972) found eggs of E. maculatum on the undersides of stones held as 

 territories by males. To date, no other species of Nothonotus had been 

 reported as an egg-clumper. 



On 5 May 1981 we found four nests of E. aquali in a large rubble 

 riffle in Buffalo River, Lewis County, Tennessee. The water was swift, 

 22° C, and averaged 30 cm deep where the nests were found. Eggs were 

 difficult to find in the swift water, and it was even more difficult to capture 

 the male in association with the nest. However, one 63 mm SL male was 

 captured beneath a stone to which a clump of eggs was attached. (Fig. 

 IF). 



Nests of E. aquali were similar in construction to those of E. 

 maculatum as described by Raney and Lachner (1939). Unlike the 

 single-layer clusters of species of the subgenera Boleosoma and Catono- 

 tus, nests of E. maculatum and E. aquali contain a multi-layer clump of 

 eggs. Each nest contained eggs in various stages of development, which 

 obviously were the results of more than one spawn. One nest, removed 

 and preserved for an accurate egg count, contained 551 eggs averaging 

 1.8 mm in diameter. 



Two male and four female E. aquali, 50 to 65 mm SL, were col- 

 lected in Buffalo River on 5 May 1981 and returned to INHS. On 8 

 May they were placed in an 80 1 aquarium, at 24° C, outfitted with a 

 current pump. Two stones were propped with the undersides accessible 

 as nesting sites. Observations were made through the next two days but 

 no spawning activities were seen. However, by 0800 hr on 11 May a 

 male had established a territory under the smaller of the two stones (the 

 other male had died) and was guarding three small clumps of eggs. The 

 clumps were separated by distances of at least 2 cm, but all were in the 

 interface between the nest stone and the gravel substrate. No further 

 spawning occurred. 



The only notable behavior of aquarium-held E. aquali, other than 

 the constant attention given his territory by the breeding male, was that 

 of the females. On two occasions a female was seen to swim beneath the 

 nest stone and tightly wedge herself (more or less right-side up) in the 

 interface between the stone and gravel substrate. Although the male 

 ignored her, it appears that eggs are laid with the female wedged 



