FISH-CULTURAL PRACTICES IN THE BUREAU OF FISHERIES. 739 



to be a question, however, whether it would be feasible with the impounded 

 stock of the Bureau destined for Hberation in the open waters after removal of 

 their eggs. The experiments showed that out of 2,110 lobsters removed from 

 the pound, all of which had been plugged when put in, 742 had lost both plugs, 

 563 had lost one plug, and 605 retained both. The warm weather when they 

 are first confined, however, is their most active period, when the plugs do most 

 good. Mutilation is thus prevented and the plugs apparently work no per- 

 manent injury to the lobsters. 



It is important in the impounding of lobsters to take precautions, so far as 

 possible, for the exclusion of eels, which have an especial liking for the eggs and 

 will strip a female lobster in a very short time. Even with all precautions it 

 seems impossible to exclude eels entirely ; it is probable that many enter when 

 small and grow up in the pound. 



The rearing of lobster fry to the fourth molt, as practiced by the Rhode 

 Island Fish Commission and so admirably set forth in a paper read at the con- 

 gress," has not as yet been taken up by the Bureau, but is doubtless feasible at 

 the Boothbay Harbor station. Before the first experiments in this direction at 

 Boothbay it was thought that owing to the lower temperature of the water in 

 this more northern latitude the periods of molting would be prolonged and the 

 feeding and care of the fry consequently attended with abnormal losses. It has 

 since been found that this difficulty can probably be met by installing the 

 rearing plant in a lobster pound, where the temperature is higher and more even 

 than in the open waters. The Bureau therefore hopes to enter upon this under- 

 taking in the near future, for the purpose of rearing a portion of the lobster out- 

 put. To attempt to rear to the fourth molt the entire product of the Boothbay 

 station would involve an expenditure far beyond present financial resources. 



MEASURING AND COUNTING FISH EGGS AND FRY. 



Immediately after water hardening, for a short period varying with the 

 species and water temperature, the careful handling of fish eggs is not injurious. 

 During this period their numbers may be very definitely ascertained by the use 

 of any receptacle suitable for a measure, the capacity of the receptacle having 

 first been ascertained by counting the whole or a fractional part of its contents. 



For eggs of the trouts and those of smaller size an apothecary's graduate or 

 the ordinary graduated quart or pint measure is commonly used. For large 

 quantities the long-handled dipper used in transferring them to the hatching 

 apparatus may be advantageously utilized. As many eggs as possible are 

 poured into the measure, nearly all of the water being forced out over the rim. 



a Mead, A. D. . A method of lobster culture. Proceedings Fourth International Fishery Congress, 

 Bulletin o^ the Bureau of Fisheries, vol. xxviii, 1908, p. 219-240, pi. vii-xi. 



