22 REPORTS OF THE DEPARTMENT OF COMMERCE, 



It was learned that somewhat irregular runs of pilchards occur 

 generally along the coast from April to October, especially in the 

 regions of Coos Bay and Umpqua River. While it is believed that 

 the fish are eminently suitable for canning as sardines or otherwise, 

 the Bureau has not felt that the general trade conditions existing in 

 the canning industries justified its giving immediate encouragement 

 to new ventures in the canning of fish on the northwest coast or 

 elsewhere. It is expected that further inquiries and observations 

 may be made at an appropriate season. 



The paddlefish. — One of the important fishes of the Mississippi Basin 

 which is diminishing in numbers and seems threatened with extinc- 

 tion is the paddlefish, which is valued to some extent for its flesh 

 but principally for the roe, which is useful for preparation as a rela- 

 tively high grade of caviar. Up to the present time it has never been 

 possible to secure definite information regarding the breeding habits 

 of this fish. Realizing that a special effort must be directed at this 

 problem before it may become too late, the Bureau, in cooperation 

 with the conservation department of Louisiana, undertook a special 

 study of the breeding habits and propagation of the paddlefish during 

 the latter half of the fiscal year under report. Definite results were 

 were not secured, but it is believed that a groundwork was laid 

 which may contribute toward solution of the problem with further 

 attempts. Meantime it is interesting to record that experiments 

 initiated at the fisheries biological station at Fairport, Iowa, in 1914, 

 have shown that the paddlefish will live and grow for periods of 

 years while inclosed in an artificial body of water such as the storage 

 reservoir of the station. 



Spawning of squeteague. — An investigation into the spawning 

 habits and condition of the squeteague in Delaware Bay was con- 

 ducted in May and June, 1919. It was foimd that spawning began 

 a little before the middle of May and continued until the middle of 

 June or later. Many fish were examined, townet hauls for the float- 

 ing eggs were made, and temperatures and salinities were determined. 



This body of spawning fish supports an extensive gill-net fishery, 

 which is pursued in small skiffs, the New Jersey law limiting each boat- 

 to the use of 50 fathoms of gill net. Experiments were made in the 

 artificial fertilization of eggs from the fish thus taken; this proved 

 to be entirely feasible, and the eggs so fertilized were returned to the 

 water directly on the grounds. 



It is evident that it would be productive of good results if the com- 

 mercial fishermen should become educated to the desirability and 

 advantage of saving the ripe eggs from fish taken for market during 

 this season, fertilizing the eggs and returning them to the water. 



FISH IN RELATION TO MOSQUITO CONTROL. 



In a previous report mention is made of the practical services 

 rendered by this Bureau in cooperation with the Bureau of Public 

 Health Service in protecting the health of soldiers in Army canton- 

 ments. A report of investigation and operations conducted in the 

 vicinity of Camp Hancock has been published conjointly by the two 

 bureaus. 



In an effort to determine as precisely as possible the conditions 

 of effective control of mosquitoes by fish, the Bureau has continued 



