PROPAGATIOlSr AND DISTRIBUTION OF FOOD FISHES, 1922.» 51 



main body of fish spawn in August and September in the vicinity 

 of Gloucester, Mass. It appears also that the eggs of the pole 

 flounder can not be successfully transported from the point of col- 

 lection to the hatchery by the methods now in use in connection 

 with the other species handled. 



WOODS HOLrE (MASS.) STATION. 

 [W. H. Thomas, Superintendent.] 



As a result of arrangements made with the fishermen in October, 

 to furnish cod for a brood stock, consignments began arriving 

 November 10, and shortly thereafter additional deliveries brought 

 the total for the season up to 4,023. This was somewhat more 

 than the work required, and it was really in excess of holding 

 facilities, but the supply available varies from season to season, 

 and as conditions in this respect can not be foreseen, it is necessary 

 to accept the stock brought in to insure future cooperation in the 

 work on the part of the fishermen. The first consignment of brood 

 cod was transferred to the cistern in a sea-water temperature of 50° 

 F. Experience has shown that the best results can not be expected 

 from such transfers in a water temperature exceeding 45°, and in 

 future an effort will be made to profit by such experience. In order 

 to obviate the possibility of purchasing immature brood fish, all 

 fishermen were especially requested not to take any cod for the 

 station in the vicinity of the shore, and it was evident from their 

 description of the places of capture that the fish were secured at 

 j)oints where spawning cod are known to congregate. As in past 

 years, the females outnumbered the males, but this could not be 

 remedied, owing to the necessity of accepting all deliveries. The 

 average weight of the brood fish was 6| pounds, somewhat in excess 

 of the usual average. Despite the fact that the quality of the stock 

 as a whole was first class and the egg collections large, the per- 

 centage of hatch was disappointing. This is accounted for by the 

 partial failure of the automatic temperature control to operate, 

 the temperature at times fluctuating between 35 and 40° F. instead 

 of remaining constant at 38. Salt appeared to collect on the valve 

 and check its operation. 



Trouble was encountered also from an accumulation of air in 

 the cod boxes. This was particularly noticeable just after the filter 

 was cleaned, there being so much of it at times that circulation was 

 stopped, killing the sj^awn. Under the new arrangement effected 

 last year the water supply for the hatchery is now pumped from 

 the harbor into two wood stave tanks of 8,000 and 10,000 gallons 

 capacity. Until the temperature drops to 38° F. it flows by gravity 

 from these tanks to the hatcherj'^ through 6-inch pipe, thence through 

 connecting 4-inch pipes to 2-inch lines extended over each set of 

 tables, and from there through f-inch pet cocks and connecting 

 rubber tubes to the hatching boxes on the tables, the overflow from 

 the boxes passing into a drain and back into the harbor. After 

 the temperature has reached 38° the water is passed through pipes 

 to a heating tank in the boiler room and the direct supply to the 

 hatchery practically stopped. The overflow from the hatching 

 boxes is then run into the cod cistern. The overflow from the 



