260 DESCRIPTIVE KEY TO PAGES Uh TO 



eggs and young. Once hatched they are easily grown by the same 

 methods as used for other tropical fishes. Breeders should be well 

 fed up on mosquito larvae, young tropical fishes or freshwater 

 shrimps. They also eat Water-boatmen. Breeding temperature, from 

 7~> degrees to 80 degrees. The female develops an egg-laying tube 

 just prior to spawning. Otherwise there is no known way of dis- 

 tinguishing the sexes despite much study of the subject. 



INDEX TO NATURE OR TEMPERAMENT OF FISHES 



Different persons zvill have varying experiences with the same kinds 

 of fishes under apparently identical conditions. In fact, one's own obser- 

 vations will sometimes change from year to year. The writer, for 

 instance, has heretofore alzvays found that Mexican Swordtail fishes kill 

 Coral Snails, yet this year they are living together in perfect accord. 

 Therefore, zve bespeak the indulgence of those zvhose obseri'ations do not 

 agree in all details ivith the statements here published. The data have been 

 gathered from the most experienced experts the world over, and while 

 some minor points may, from time to time, be open to question, the main 

 facts stated are authentic and should form a practical guide for the 

 handling of nearly all known varieties of aquarium fishes. 



Nl GROUP 



Indicates that fish so marked are of a generally peaceful disposition, 

 not disposed to hunt trouble nor to persecute or devour other species 

 kept with them. This fact applies mainly to the Barbus group among 

 tropical fishes and the Cyprinoid minnows in the temperate division. 

 However, large fish of any kind take advantage of their size and tyran- 

 nize over their associates more or less and also monopolize the food. So, 

 even if a fish is indicated "Nl," it is as well to keep only such fish 

 as are of approximately the same size together — just as large young fish 

 should be separated from smaller ones of the same species. 



N2 GROUP 



Fish of this class are generally amiable and peaceable and are mainly 

 of the live-bearing tooth-carp group. Some of these, again, such as 

 Gambusia affinis and varieties, Pseudoxiphophorus bimaculata, Phal- 

 loceros caudimaculata and Belonesox belizanus, should only be kept with 

 their own species. Males which "rule the roost" will fight with their 



