Pulmonata 523 



REARING AQUATIC SNAILS 



Wendell Krull, U. S. Bureau of Animal Industry 



USE water which has been kept in stone jars in subdued light for 

 several weeks; if the water becomes acid on standing, add enough 

 calcium carbonate to cover the bottom of the container. All water 

 should be filtered through coarse filter paper before it is used in aquaria. 

 If these precautions are taken algae, which are a constant nuisance in 

 most cases, are largely eliminated. Snails, apparently, thrive best in 

 alkaline water and no success has been had in using acid water, although 

 one species, Pseudosuccinea columella, has grown and matured in water 

 having a pH of 5.5. 



FEEDING, FOOD, AND ITS PREPARATION 



In rearing many of the freshwater pond snails, only two kinds of 

 food, dead leaves and lettuce, appear to be necessary. Some snails may 

 complete their development when fed on either the dead leaves or on the 

 lettuce, while others change from one to the other during their develop- 

 ment; however, most of them can survive for some time on dead leaves 

 alone. In view of this fact it is a good plan to keep a few dead leaves in 

 the aquarium as an emergency measure. Such snails as Fossaria modi- 

 cella, F. m. rustica, Gyraulus parvus, and Planorbula armigera may be 

 raised successfully on dead leaves, and Pseudosuccinea columella and 

 Lymnaea palustris on lettuce, while Helisoma trivolvis requires dead 

 leaves when hatched and lettuce when some growth has taken place if 

 they are to be raised without excessive mortality. 



Dead leaves. Leaves from maple trees are superior to any of the 

 numerous kinds of leaves which have been tried in snail culture. The 

 leaves may be gathered any time during the summer and cured by 

 placing them in a sack or screen container and hanging in the sunshine 

 for 6 or 8 weeks. The drying of the leaves may be shortened considerably 

 if they are collected at the time they are being shed in the fall ; they may 

 be dried on a radiator or near a stove. After the leaves have been 

 thoroughly dried and cured they should be placed in a glass container 

 and covered with the same kind of water which is to be used in the 

 aquaria. The leaves should be soaked for three days, changing water 

 twice daily, after which they should be dried by spreading them out on 

 paper. The leaves are then ready for use in aquaria as desired; when 

 used they should be placed on the bottom of the aquarium after they 

 become moistened. It is desirable that the leaves be kept intact as much 

 as possible. 



Lettuce. Head lettuce is much superior to leaf lettuce because of its 

 keeping qualities, both in the refrigerator and in aquaria, and because 



