18 



AQUARIUM MANAGEMENT 



known, most satisfactory and easily obtained are the large Japanese 

 Snails (Viviparus malleatus), the so-called African Paper-shelled Snail 

 (Lymnaea auricularia), the Ramshorn Snail (Planorbis), and the Pond 



Fig. 7. African Fig. 8. Red Ramshorn Fig. 9. Japanese 



The Best Freshwater Aquarium Snails (Life Size) 



Snail (Physa). These are all active in eating mossy growth from the 



glass, or particles of food which the fishes have not taken, and in no 

 case will they injure any of the aquarium plants. Most snails consume 

 decomposing animal matter, such as dead tadpoles, fishes, etc. Living 

 snails will not injure young nor adult fishes, nor pollute the water. 



Snails are sometimes useful trouble-indicators. If they persist in 

 staying at the edge of the water, it may have turned foul. They will also 

 do the same thing if new water has not been seasoned. They seem to 

 have a distinct objection to an excess of oxygen in the water. 



Japanese Snails are very interesting in that they bring forth fully 

 developed young about the size of a small pea, able to take care of them- 

 selves among goldfishes. These snails are either male or female, but a 

 female once impregnated seems, like a queen bee, to remain fertile for the 

 remainder of her life. The right horn of the male is somewhat the shorter, 

 this serving a sexual purpose. These snails are quite long-lived and 

 grow to the size of a large walnut. They can be identified by the slightly 

 raised keels showing on the last spiral. Another snail resembling the 

 Japanese species is the Potomac Snail. Running in the direction of the 

 spiral are three brown stripes on a horn-colored background. It is quite 

 attractive and is frequently sold as the Japanese Snail, but it is too slug- 

 gish to be of much real value. 



