T 



Homaridae 233 



Family crangonidae 



A METHOD FOR REARING SMALL CRANGONIDAE 



Hugh H. Darby, College of Physicians and Surgeons 

 HE rearing of these organisms seems to have given trouble to 



JL several investigators. By the following technique it has been pos- 

 sible to keep them alive for at least three months. Small embryological 

 dishes, about 12 cm. in diameter, were used, one for each animal. If 

 two are placed together in the same dish, they tear each other to pieces. 

 No running water was used, but the seawater was changed once every 

 2 or 3 days. Some of the small Synalpheus were kept in similar dishes 

 without any change of water for 10 days without ill effects. A change 

 of water just after molting is harmful. Much better results were obtained 

 when the organisms were kept for at least 24 hours in the same water in 

 which they had molted. During this time they devoured their own cast 

 skin, and needed no other food. Ordinarily the muscles of small fishes 

 or of other Crustacea were supplied for food. If kept in the ice box for 

 two or three days before use, the food was devoured more readily than 

 when given fresh. Very small pieces were given, so that there was no 

 remnant left to become a source of bacterial infection in the culture 

 dishes. Small marine algae kept in the dishes furnished both aeration 

 and food. Larvae need much more aeration than adults for survival. 

 Temperatures between 22 ° and 30° C. were entirely satisfactory for 

 organisms found in the Dry Tortugas islands. 



Bibliography 

 Darby, Hugh H. 1934. The mechanism of asymmetry in the Alpheidae. Carnegie 

 Inst, of Wash. Publ. No. 435. 



Family homaridae 



HATCHING AND REARING LARVAE OF THE AMERICAN 

 LOBSTER, HOMARUS AMERICANUS 



Paul S. Galtsoff, U. S. Bureau of Fisheries 



THE range of the American lobster extends from Labrador to North 

 Carolina. Every spring lobsters migrate from deep water inshore 

 where they remain until the onset of cold weather. At Woods Hole, 

 Massachusetts, they usually appear in large numbers in May and begin 

 their outward migration in October. Many of them remain in relatively 

 shallow water throughout the winter. 



The copulation of lobsters occurs primarily in the spring. During this 

 time the sperm is deposited in an external seminal receptacle situated 



