448 PARENTAL CARE AMONG FRESH-WATER FISHES. 



An interesting lialiit of tlie parents, more especially the male, observed dur- 

 ing the first few days after hatching was the mixing and stirring of the masses 

 of young by means of the barbels. With their chin on the bottom, the old fish 

 approached the corners where the fry were banked and, with the barbels all 

 directed forward and flexed where they touched the bottom, thoroughly agi- 

 tated the mass of fry, bringing the deepest individuals to the surface. This 

 act was usually repeated several times in quick succession. The care of the 

 young may be said to have ceased when they began to swim freely, although 

 the parents continued to show solicitude when the attendant approached the 

 aquarium from the rear. 



The after fate of the brood is suggestive of some of the cotiditions 

 and accidents which beset the path of young fishes and indicates why 

 the number of adult fishes does not vary more from year t-o year in 

 hpite of the immense number of eggs and progeny yiekled by a 

 mother fish. 



When 12 days old about 1.500 of the fry were removed from the aquarium 

 to relieve crowding, and placed in a hatching trough such as is employed for 

 .salmon and trout. For some unknown cause, 1,000 of these died during the 

 first three days. The others survived with little or no loss, and are still on hand. 



The fry which were left with their parents continued healthy, but their num- 

 ber steadily decreased. There being no way for them to escape, and a closely 

 woven wire screen preventing inroads from the exterior, it was suspected that 

 the old fish were eating their young, though they were liberally fed at suitable 

 intervals. They were kept under close abservation during the day, and were 

 seen to be fond of mouthing the fry, more especially the weaker ones — a habit 

 which at this stage seemed unnecessary. They were frequently seen to follow 

 leisurely a fry, suck it in their mouth, retain it for a while, and then expel it, 

 sometimes only to capture it again. There was no active pursuit of the fry, 

 and the tendency seemed to be to spit them out. In one or two instances, 

 however, it appeared that fry taken into the mouth were not liberated, the 

 feeding instinct becoming paramount to the parental instinct. After all the 

 fry which had been left with their parents had disappeared — in about six weeks 

 after hatching — IS from the trough were placed in the aquarium one evening, 

 and only 2 of these had survived on the following morning. 



During the entire period covered by these observations liver and beef were 

 fed regularly to the brood fishes, and at no time did their appetites fail. There 

 was apparently no interference with deglutition, or closure of the oesophagus, 

 such as has been observed in some other catfishes, as half-inch cubes of meat 

 were readily ingested during the entire time the fish were under observation. 



PIMELODINES, OR SOUTH AND MIDDLE AMERICAN CATFISHES. 



Much like the North American catfishes jire most of those of South 

 and Middle America, but they have only six barbels instead of eight, 

 the missing ones being the nasal; as in the Ameiurines, however, 

 their nostrils are remote and not close together as in the Tachisurines. 



The attitude of the parents to the young among the Pimelodines is 

 unknown in most cases, but it is probably analogous to that prevalent 

 among the North American fishes. There is, however, a remarkable 

 deviation from the latter and doubtless from its relatives of the sub- 



