THE AQUATIC VERTEBRATES 1045 



or in other protected places and guarded by the male. The male 

 Noturus not infrequently proceeds to swallow the eggs he guards 

 when they are uncovered. 



"Both 1 parents of the yellow catfish are a pale yellow color, 

 the number of eggs deposited was estimated at two thousand. 

 The incubatory period was five days in a mean water temperature 

 of 77 F., the lowest temperature being 75 degrees and the highest 

 80 degrees. 



" During the entire hatching period both parents were incessant 

 in their efforts to prevent the smothering of the eggs, to keep them 

 clean, and to guard against intruders. The eggs were kept con- 

 stantly agitated and aerated by a gentle fanning motion of the 

 lower fins, and foreign particles, either on the bottom of the nest 

 or floating near the eggs, were removed in the mouth or by the 

 fins. The most striking act in the care of the eggs was the sucking 

 of the egg masses into the mouth and the blowing of them out, 

 this being repeated several times with each cluster before another 

 lot was treated. 



"The male was particularly active in watching for intruders, 

 and savagely attacked the hands of the attendant who brought 

 food; he also rushed at sticks or other objects introduced into the 

 aquarium. Practically the entire work of defence was assumed 

 by the male, although the female occasionally participated. 



"During the time the fry were on the bottom the attentions of 

 the parents were unrelaxed, and, in fact, were increased, for the 

 tendency of the different lots to become scattered had to be cor- 

 rected, and the dense packing of the young in the corners seemed 

 to occasion much concern. The masses of fry were constantly 

 stirred, as the eggs had been, by a flirt of the fins, which often 

 sent dozens of them three or four inches upward, to fall back on 

 the pile. 



"The very young fry were also taken into the mouths of the 

 parents and blown out, especially those which became separated 

 from the main lot and were found in the sand and sediment. The 

 old fish would take in a mouthful of fry and foreign particles, 

 retain them for a moment, and expel them with some force. After 

 1 From Smith & Harron, Bull. U. S. Fish Com., 22: 151. 



