DESCRIPTIVE KEY TO BREEDING, ETC. 239 



on stones, or on the aquarium, on the convex side of a flowerpot laid 

 on its side, or on porcelain. Eggs hatch in from 3 to 6 days, during 

 which period the parents take turns in swimming over the eggs and 

 fanning fresh water over them constantly. When the young hatch, the 

 parents carry them in their mouths and deposit them in a depression 

 previously made in the sand at the bottom, where they jealously guard 

 them against all comers — terrestrial or aquatic — frequently removing 

 dirt from the "nest" and transferring the baby fish to new nests. For 

 several days after hatching the young eat nothing, but live in a swarm 

 at the bottom, while they absorb the yolk-sac. At the end of this period 

 they begin to "look like fish" and to swim around their parents in a 

 "cloud." They then require first infusoria and later very fine daphnia. 

 The parents may be removed any time after the young begin to swim. 

 They require much room and clean pure water of a constant tempera- 

 ture of 78 or over. The dirt should be siphoned off the bottom occasion- 

 ally and fresh water of the same temperature added. 



Artificial incubation of the eggs of this group of fishes is secured 

 by the use of compressed air liberated in the water in such position and 

 volume as to produce a gentle circulation. Water must be clear. Parents 

 and eggs are, of course, separated. This method is very successful and 

 is used by wholesale breeders. Removal of eggs into clear water of same 

 temperature has proven effective, even without circulation. 



We have recently observed that fishes of this general type have a 

 decided preference for spawning on a light-colored object, such as a 

 piece of marble or other light stone. We have not tried white porcelain 

 or crockery, but they should be successful, we believe. 



No. 6 A 



Pterophyllum scalare varies from the foregoing in that at no period 

 do the parents place the young in depressions in the sand. They have 

 a pronounced preference for depositing eggs on broad, firm leaves, like 

 giant Sagittaria. These fishes in captivity are very apt to eat their eggs, 

 and the chances of successful propagation are greater if the parents or eggs 

 are removed as soon as egg-eating is observed. Eggs should be in a clear, 

 clean aquarium. Artificial circulation of water is desirable but not in- 

 dispensable. 



Haplochromis multicolor and Tilapia macrocephala are also Cichlids, 

 but their breeding habits are quite different. They are mouthbreeders. 

 After the eggs are dropped and fertilized, one of the parents places the 

 eggs in the mouth and keeps them there until hatched, and for about 

 two weeks more. With H. multicolor it is the female who assumes this 

 arduous task, while with T. macrocephala it is the male. Further infor- 

 mation on these species will be found under their illustrations. 



