16 AMEEICAN CATFISHES. 



of the case are that the catfish were caught in the vicinity of a salmon cannery, and 

 that the spawn was among the fish offal thrown into the bay, and the young fish were 

 "split-tails" and not valuable for food purposes. 



The facts of the case as stated do not prove that catfish may not be 

 injurious to salmon. The chances are that if they would eat salmon 

 spawn as offal, and living "split-tails," they would eat naturally 

 deposited spawn and young salmon of the "split-tail" size if they 

 had access to them. 



Smith says:" 



The catfish have a reputation among the California fishermen of being large con- 

 sumers of fry and eggs of salmon, sturgeon, shad, and other fishes. This accords with 

 their known habits in other waters. Mr. Alexander's examination, however, of the 

 contents of several hundred stomachs of catfish in California and Oregon yielded only 

 negative results as to the presence of young fish and ova. Writing of the bullhead in 

 Clear Lake, California, Jordan and Gilbert say that it is extremely abundant and is 

 destructive to the spawn of other species. The scarcity of the valuable Sacramento 

 perch in that lake, which they attribute to the carp, here as in the Sacramento 

 River, may be partly due to the more numerous catfish, which feed almost exclu- 

 Bively on animal matter. 



BREEDING HABITS. 



Probably less is actually known of the breeding habits of most of 

 the species of catfishes than of their other habits, yet observations have 

 been made upon two or more species with sufficient detail to warrant 

 the assumption that in the main the habits of most species are essen- 

 tially alike. Speaking of Idalurus punctatus, Jordan says that it 

 spawns in the spring, but that its breeding habits have not been 

 studied. Mr. Jones (loc. cit.) says this species spawns when 1 year old, 

 and twice a year — in May and in September. In the preceding spring 

 he procured eight wild ones. After feeding them well up to this time 

 (October 31), they had spawned in May and September and filled his 

 pond. He says that they take care of their own young and trouble 

 no other fish. 



Ryder '' thus describes the breeding process of a pair of Potomac 

 channel cats (Ameiurus catus) in the aquarium at Washington: 



A number of adult individuals of Ameiurus albidus were brought from the Potomac 

 River lo the Armory building at the instance of Lieut. W. C. Babcock, U.S. Navy, 

 and Colonel McDonald, and deposited in the large tank aquaria of that institution 

 about the close of the shad-fishing season of 1883. One pair of these have since bred 

 or spawned in confinement, and thus afforded the writer the opportunity of observing 

 and describing some of the more interesting phases of the development of this singu- 

 lar and interesting family of fishes. * * * Its habits of spawning and care of the 

 young are probably common to all the species of the genus, and are quite remarkable 

 as will appear from the subjoined account. 



On the morning of the 13th of July, a little after 10 o'clock, we noticed a mass of whitish 

 eggs in one of our aquaria inhabited by three adult specimens of Ameiurus albidus, 



a Smith, H. M.: A review of the history and results of attempts to acclimatize fishes and other water 

 animals in the Pacific States. Bull. U. S. Fish Commission, vol. xv, 1895, p. 387. 



b Ryder, John A.: Preliminary notice of the development and breeding habits of the Potomac catfish, 

 Ameiurus albidus (Le Sueur) Gill. Bull. U. S. Fish Commission, vol. in, 1883, p. 225. 



