Cancridae 241 



portant to avoid crowding a large number of individuals within a small 

 quantity of water. The chances of survival, where crowding cannot be 

 avoided, would seem to be best where water is not used. When covered 

 with damp seaweed crabs will live for many hours and often for days. 



REQUIREMENTS FOR KEEPING ALIVE 



Small larval and post-larval crabs were successfully kept by the writer 

 for considerable periods of time, sometimes for several months, in mis- 

 cellaneous glass vessels of all available kinds. These containers were 

 mostly of the type in which foods are put up and were the only vessels 

 readily available in the small seaside community where the work was 

 carried on. Before being used, all the containers were carefully washed 

 in boiling water. In general large shallow vessels seemed to be the most 

 successful. 



Into each container was placed one small crab, some clean sand, one 

 or two pebbles, and a piece of seaweed. Small sticklebacks were found 

 useful for keeping the water in circulation in the individual containers 

 and were sometimes used for this purpose. It was, however, necessary 

 to replace the small fish from time to time since, though they were con- 

 siderably larger than the crabs, they were frequently caught and partially 

 devoured. 



Running water was unfortunately not available but satisfactory results 

 were obtained by changing the water twice daily. 



The larger crabs were kept in compartment live-wells anchored to a 

 float. The live-wells were designed to facilitate the natural circulation 

 of water due to the tidal currents. Compartments of various sizes were 

 provided for large and small crabs. Live-wells of 3 feet x 4 feet x 9 

 inches were found to be as large as could conveniently be handled and 

 two of these dimensions were put in use for two seasons. 



FOOD 



The young crabs were fed mainly on small pieces of absolutely fresh 

 sticklebacks, a decided preference for fresh rather than stale fish having 

 been shown in feeding experiments. Sticklebacks were readily obtain- 

 able with the use of a small dip net and proved very acceptable to the 

 crabs. Small pieces of oyster were occasionally given but proved to be 

 less satisfactory than the fish. 



Fresh fish heads and entrails were used as food for larger crabs. 



References 



Family Xanthidae 



For the culture of Lophopanopeus bellus see p. 237. 

 Family Grapsidae 



For the culture of Hemigrapsus nudus see p. 238. 



