244 DESCRIPTIVE KEY TO BREEDING, ETC. 



the hot summer months. The young must have a constant supply of 

 infusoria, prepared beforehand by the methods described elsewhere in 

 this book, until they are large enough to eat very finely screened 

 Daphnia. Do not introduce the Daphnia while still feeding Infusoria. 

 Daphnia do not, as has been supposed, devour Infusoria, but in large 

 numbers they consume so much oxygen that the Infusoria die. Nearly 

 all fishes will eat their own eggs and young, even the ones showing great 

 parental care often forgetting and devouring their own offspring. Except 

 when absolutely necessary, parent fish should be kept away from their 

 young. Some fishes are like other animals in captivity, especially when 

 closely confined. They destroy their young when in fear of having them 

 fall into the hands of man. Liberal feeding tends to prevent cannibalism. 



TEMPERATURE FOR TROPICAL FISHES 



A good practical temperature for general use is 75 degrees Fahrenheit 

 or 24 degrees Celsius. Ichthyophthirius and other diseases will seldom 

 appear at this temperature. Most tropicals will do fairly well at 70 

 degrees, but here one is flirting with danger, because a drop of a few 

 degrees from this point is likely to cause trouble. 



If, through some unavoidable circumstance, the water has been 

 chilled to the very dangerous point around 60 degrees, a special effort 

 should be made to gradually raise the temperature to 75 to 80 degrees 

 to anticipate and counteract any injurious effects. 



Higher temperatures are required for breeding some of the fishes, as 

 is noted on the pages just preceding this. 



Temperature for goldfishes is covered in the early part of the book, 

 and their requirements apply to most of our native aquarium fishes also. 



THE "HAPPY FAMILY" AQUARIUM 



In a small aquarium without many plants one must be careful to 

 select only the most amiable of fishes for mixing together. Nearly all 

 members of groups 3, 7, 8 and 18 are perfectly safe, except in the few in- 

 stances noted. 



There is a world of difference in a large aquarium (25 gallons and 

 upward) which is thickly planted and having rock, flowerpot, pipe or 

 other refuges. Then we may also safely add members from groups 2, 5 

 and 19. The individual fishes comprising groups will be found in the 

 list on pages 286-297. 



One of the main things to keep in mind is not to have too great a 

 difference in the sizes of members of the "happy family" aquarium. 



A very attractive aquarium of mixed native temperate-water fishes 

 can be made up, comprised of those we have described in Chapter Twelve, 

 except for Sticklebacks and the more aggressive Sunfishes. 



