102 FISH ENEMIES 



They rapidly deplete an aquarium of daphnia and newly hatched 

 fishes. When a school of fry under 5-16 inch long is disappearing without 

 apparent cause, it will be well to take a sharp look for hydra. 



Hydra possess a poison which quickly stupefies their prey, and to 

 fish large enough to eat the hydra this poison doubtless has an unpleasant 

 taste. There is no fish known which will eat them. To get rid of this 

 pest, remove all fish, snails, etc., from the tank and place in it one tea- 

 spoonful of household ammonia to five gallons of aquarium water. 

 Allow this to stand for two hours, change water and replace fish. This 

 treatment will not kill plants. Raising the aquarium temperature to 

 110 degrees F. for a few minutes will also destroy hydra. 



LARGER ENEMIES OF FISHES 



It should not be understood that the foregoing are the only serious 

 enemies of pet fishes. In the greenhouse, outdoor pool, or even the 

 library, misfortune is liable to descend in various guises. Chief among 

 these are the cat, rat, muskrat, snake, heron, kingfisher and small boy. 

 Fishes are also taken by the sandpiper, horned owl, blackbird and 

 crayfish. The blackbird specializes on picking out the eyes of telescopes, 

 if the water is near enough to the edge of tank for him to reach them. 

 Frogs will eat fishes of nearly their own size. Slow-moving fancy gold- 

 fishes are easy prey for them and inexperienced fanciers have lost many 

 of their best specimens through ignorance of this menace. Rats are 

 extremely daring and resourceful in finding ways to get at goldfish tanks, 

 especially in greenhouses, where they cause great losses to fish stock. 

 They will even burrow from the outside and gnaw their way through a 

 weak portion of cement flooring. 



Kingfishers can be destroyed by setting a steel trap on the high look- 

 out point where they watch for their victims. The trap is not baited. 

 It is set off by the bird alighting on the trigger. Aside from this suggestion 

 the owner of the fish will have to use his personal ingenuity to combat 

 these enemies as occasion arises. The author must here content himself 

 with pointing out the possible sources of trouble. 



It very rarely happens that a large goldfish is an offender in a peculiar 

 and surprising way. This is in the gentle and shocking art of sucking 

 the telescopic eyes out of other goldfishes. If the owner of telescopes 

 finds one of his pets with an empty eye socket he should do a little de- 

 tective work to find the culprit among the other fishes and place it where 

 no further damage can be done. The loss of an eye in this way never 

 seems to seriously inconvenience the victim. 



