First Pnrt 



Rearing of larval lobs ters; 



The fulfillnent of the plan for the rearing of larval lobsters 

 has obliged Laval University to make oonsiderable expenditures dvu'ing 

 the years 1944 and 1945 for the construction and fitting out of the 

 rearing establishnent. It is only at the begintiing of the 1946 

 season that the final details of the equipping have been conpleted» 



Days of operation ; 



The rearing establishment has been put in operation the 1st of 

 July with the arrival of the first larvae and has functioned without 

 interruption during 65 days, viz., up to the 3d of Septeiaber* 



Yfater tein;[Derature of the rea r ing_ b a sins ; 



The previous labors have demonstrated that the water temperature 

 of the rearing- basins v/as an important factor. The ideal temperature 

 is from 18.0° to 19o0" C, (65.0° F.) In the course of nine weeks of.; 

 operation, thanlcs to a rigorous supei^ision of the heating and pump- 

 ing systems, the mean deviation of the reading tanks has been main- 

 tained between 18.1 and 19,6° C» and this despite the important 

 deviations of the temperatiu'e of the sea water pumped to supply the 

 resdrvoir* 



The average variation of the temperattire (minimum andmaxinun) 

 betiveen the water of the sea and that of the rearing tanlcs is reported 

 in Table I for successive weekly periods. 



In Table II are grouped, for the periods of a v/eek of operaticn, 

 the average temperatures of the pumped sea water and the sea v/ater 

 in the rearing tanks; in the third coltuoij, the difference betrreen the 

 two values represents the average heating necessary to bring the 

 pumped water to the temperature advocated for rearing. 



If one calculates the average for the 65 days during which the 

 establishment has been in operation, one gets 6.74°, and by a simple 

 calculation one arrives at the folloviring result; for heating the 

 quantity of 36,000 gallons of water used daily, one must furnish 

 about 10,600,000 calories per day. 



Rearing tanks; 



The rearing of larval lobsters has been carried on in t^'/c types 

 of tanks, namely four oval concrete tanlcs and two vrooden tanlcs of the 

 type in usage at Boothbay Harbor, Maine. 



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