he had thus assumed the care of the eggs, one 

 more attempt to spawn was observed; but there 

 was no further deposition of eggs . The female 

 remained quietly to one side, occasionally cir- 

 cling, but the male hovered over the eggs and 

 promptly began the activities necessary for 

 their care. From then on, the female was per- 

 mitted less and less to be near the eggs. The 

 male drove her away as he did any other intrud- 

 er. The biting of a hand or some object 

 inserted in a keg or can containing a brooding 

 male is familiar to fish-culturists. 



When the male assumed a position over 

 the eggs, his pelvic fins alternately beat con- 

 tinuously. He generally faced the same direction. 

 Occasionally he circled away from the eggs and 

 then returned. The most striking activity was 

 exhibited by the male when he vigorously wiggled 

 his body and pressed and packed the eggs with 

 the flat side of his pelvic fins in a manner that 

 shook the entire egg mass . As he "worked the 

 eggs" he moved forward from one end of the egg 

 pile to the other, which gave the impression 

 that he was walking on his fins. This action was 

 similar to the "run" of the female during the 

 spawning act . 



Obviously such an act served to aerate 

 the developing eggs, especially those deep in 

 the mass, but it might also serve to move the 

 embryo in the shell . This idea is supported by 

 the fact that good incubation and hatching is ob- 

 tained at some hatcheries by the paddle-wheel 

 method, which stimulates to some degree the 

 agitation of the eggs by the male . Also, eggs 

 removed from under a brooding male or hand 

 stripped and fertilized with sperm macerated 

 from the testes did not hatch as well as those 

 attended by the male, although ample aeration 

 and fresh water were provided. 



Vigorous males worked the eggs every 

 5 to 10 minutes the first day or two, but later in 

 the Incubation period the workings were less 

 frequent. Less vigorous males worked the eggs 

 every 20 to 30 minutes . After several workings, 

 the edges of the egg mass sometimes pulled 

 loose from the tar -paper mat. The eggs were 

 loosened more when the male pulled at the eggs 

 with his mouth. Murphree (1940) apparently 

 observed this activity and claimed that dead eggs 

 were removed at this time. We never observed 



any males removing dead eggs in any manner 

 and further have observed dead eggs on the top 

 of the mass throughout the incubation period. 

 According to Smith and Harron (1904) the male 

 bullhead, A_. nebulosus, picked up the eggs in 

 his mouth and spit them out again. This pro- 

 cedure was also practiced with the young fry, 

 sometimes with fatal results. We never ob- 

 served channel catfish taking the eggs completely 

 in their mouths. One male was seen trying to 

 move a loose egg mass that had shifted from the 

 center of the aquarium by placing his snout under 

 the edge of the mass and carrying it a little 

 forward as he swam . 



We have seen spawn in kegs in hatchery 

 spawning pens which became free and some which 

 stuck quite fast. When a mass became loose 

 from the tarpaper in an aquarium, no eggs were 

 left behind. 



The type of nest surface and the amount 

 of silt in the nest or water may determine whether 

 or not the eggs remain attached. The fact that 

 the eggs may be loosened suggested to us that 

 kegs with a lip or a depression might aid the male 

 in keeping a loose egg mass in the keg, and indeed 

 this is the type of container found most satis- 

 factory by practically all channel catfish 

 culturists. 



Breder (1935) reported that a pair of 

 Ameiurus nebulosus continued to fan for 10 days 

 the site from which eggs were taken, and that 

 this activity ceased the same day the eggs hatched 

 in the laboratory. He suggested that the spawning 

 act "wound up" some mechanism that simply ran 

 down. Male channel catfish separated from their 

 spawn did not exhibit such behavior, either when 

 the eggs were removed or when the fish was re- 

 moved from the eggs. The eggs probably stimu- 

 late the paternal behavior of the male. This 

 hypothesis was checked when both the eggs and 

 male were transferred from one aquarium to 

 another. The male continued to attend and care 

 for the eggs . 



One 15-inch male was used to incubate 

 three spawn, two of his own and an additional one . 

 This male received a severe injury to his right 

 eye during his second courtship. He was injected 

 interperitoneally on alternate days with approx- 

 imately 75,000 units of penicillin in sesame oil. 



8 



