94 FISH DISEASES 



The most common disease among them is ichthyophthirius, already 

 described. This epidemic kills more tropical fishes than any other 

 cause. 



As stated in the Chapter on Heating a good plan is to suspend the 

 glass portion of an electric bulb in water. It is again mentioned here be- 

 cause it is a splendid emergency method of raising the temperature in any 

 particular aquarium. The greatest heat is obtained from the old style 

 carbon filament, particularly from an old bulb. While this gives less light, 

 it generates more heat. 



Wounds, Ulcers, Etc. All fishes are liable to injuries, but in this 

 paragraph we have particularly in mind that not infrequently some 

 savage tropical fish " beats up" another. If the victim is not too far 

 gone, there is a slim chance of saving it. Swab the injured parts with 

 coal oil and return the fish to slightly salted water which has been boiled 

 and cooled. Daily treatment may be necessary. Usually within three 

 days the fish will either die or pass the danger point. When the injury 

 is confined to a small location the spot may be touched with 2% mer- 

 curochrome (usual commercial strength). Turlington's Balsam has been 

 used with success on injuries, especially on marine fishes in public 

 aquaria, where wounds are apt to be of a serious nature. 



Scales knocked off will in time be replaced if the fish passes the 

 first week without developing fungus. 



Sometimes fishes, particularly Pterophyllum scalare, are occasionally 

 attacked by some affection which eats a hole into the flesh. Perhaps it 

 is an ulcer. At any rate, without treatment it terminates fatally. This 

 may be healed by swabbing into the opening with an equal mixture of 

 tincture of iodine and tincture of aconite, applied by a little absorbent 

 cotton rolled on the end of a toothpick. A few treatments suffice. 



In General. There are times when a fish gradually sinks into an 

 emaciated condition without apparent cause and without serious loss 

 of appetite. The belly becomes hollow and the back arched. This is 

 more apt to be the case with tropical fishes, particularly with females of 

 the livebearing group that have bred freely. It seems to be the natural 

 end of life and there is nothing much to do about it. Many of the 

 tropicals mature quickly, breed rapidly and continuously. It can only 

 be expected that their natural span of life will be short. "Guppys," for 

 instance, are old in three years. 



Many correspondents inquire whether their fishes have died of 

 strangulation, on account of the fact that they were found with their 

 mouths wide open and gills distended. Dissection rarely shows anything 

 in the throat. In common with most animals their very last instinct is 

 to relax their jaws, which probably causes them to die in the condition 

 described. 



