U. S. BUREAU OF FISHERIES. 



understood. When common goldfish can be kept with no losses it is 

 time to branch out and undertake the keeping of the more interesting 

 breeds. 



A well-balanced aquarium of 5-gallon capacity is capable of main- 

 taining two goldfish, each 2 inches lono; exclusive of tail, one frog 

 tadpole, and four snails. One-fourth of the bottom area should be 

 planted with aquatic vegetation, the ends or roots to be embedded 

 from 1 to 1^ inches in the sand or gravel and the plants evenly dis- 

 tributed over the entire surface, to 

 admit light and provide for the free 

 movement of the fish. In choosing the 

 snails select species that do not feed on 

 plants. The best ones are the Planor- 

 bes and Vivipara. Snails help to keep 

 down the growth of algae, while the tacl- 

 pole acts as a scavenger, consuming all 

 waste matter in the aquarium. VHien 

 about to enter the frog stage the tad- 

 pole must be provided with a resting 

 place on the surfac# of the water, 

 otherwise it will drown. In a 5-gallon 

 aquarium two handsome specimens of 

 fringetail goldfish will make a fine 

 appearance. Once or twice a week the 

 inside surface of the front glass should 

 be cleaned, to prevent obstruction of 

 the view by accumulations of algse. 

 For this purpose a flat sponge or piece 

 of felt attached to the flattened end of 

 a stick will be effective. Sediment 

 may be removed by a glass dip tube or 

 rubber siphon. 



A 5-gallon aquarium is the minimum 

 size recommended, but when it is 

 possible a larger vessel should be used. 

 A tank 24 inches lon^, 12 inches wide, 

 and 15 inches high, with a capacity of 

 18 gallons, makes a suitable aquarium 

 for a parlor or living room. A recep- 

 tacle of that size should maintain five 

 2-inch fish of different types and varie- 

 ties, two tadpoles, and ten snails. 

 When larger aquaria are used the 

 number of fishes, scavengers, and plants 

 may be increased proportionately. If 

 the fish are larger their number should be correspondingly re- 

 duced. A good rule in stocking an aquarium is to allow 1 gallon 

 of water to each one-half inch of fish. 



Fig. 3. — Willow moss (Fontinalis anti- 

 pyratka). Natural size. A fairly good 

 oxygenator. 



LIGHT. 



The aquarium should have a northern or northeastern- exposure in 

 summer, but in winter it is advisable to so locate it that it will get 

 the sunlight two or three hours a day. The light should enter an 



