TEOPICAL AQUAEIUM FISHES 



or other means, take some fish out of the aquarium. To clear the water 

 chemically, add one grain by weight of permanganate of potash (dis- 

 solved) to each gallon of aquarium water. This will turn the water first 

 a lavender, and then a brownish color for a few days, after which it will 

 clear up. Unless the original conditions are changed, however, the water 

 will soon again become green. Before using this chemical remove all 

 snails and mussels. Goldfish can withstand the strength of the solution 

 recommended, and probably be benefitted if suffering from any form of 

 fungus. (See Chapter on Diseases.) Other fishes do not stand this 

 chemical so well. Green water, while unsightly, is not unwholesome. 

 On the contrary, a sick fish is often cured by being transferred to a tank 

 of green water. Live daphnia will clear water in a few da\s. 



How to Know When the Fishes are Sick. The first signal of 

 distress in most fish is the drooping of the dorsal (back) fin. This fin 

 should be carried stiff and upright. When the fish is sick its movements 

 are sluggish and it often seeks a quiet corner in which to hide. In some 

 of the fancy varieties the dorsal fin is so overdeveloped that the fish even 

 in health has not sufficient strength to hold it erect. When such fish are 

 ill their fins become more or less stiff, losing flexibility. Fins should be 

 clear and clean-cut. When they become thick-looking, opaque, lined with 

 red veins, overcast with red, blooshot at base of fins, or ragged and split, 

 the fish is in need of attention. (See Chapter on Diseases.) Another 

 sign of poor condition is thinness of the body. The excrement of fishes 

 in health is usually of a dark color. When it is pale, dotted with gas 

 bubbles, and of slimy appearance, the fish is apt to be out of condition. 



Sick Fishes. It is always safer to remove an affected fish from its 

 fellows. If the trouble is a contagious one, the aquarium or tank should 

 be thoroughly disinfected, not overlooking the plants in this matter. For 

 all practical purposes they can be sterilized by placing for one hour in a 

 permanganate of potassium solution, 3 grains by weight to the gallon of 

 water. Satisfactory- results will also be given by dipping plants for a few 

 moments in concentrated lime water. Either of these methods should be 

 applied to all new plants introduced into the aquarium, especially those 

 collected from the wild, or from aquaria of doubtful condition. In case 

 of an aquarium becoming contaminated it can be disinfected by dissolving 

 in it permanganate of potash to the strength already indicated, allowing 

 it to stand from two to three hours, first removing all mussels, snails and 

 fishes. In changing back to clear water again it will do no harm if a 

 little of the permanganate solution remains. 



Unless newly acquired fishes come from a source beyond suspicion 

 it is a grave risk to introduce them at once into an established aquarium 

 of healthy fish. They should first be quarantined and carefully observed 



