SEA-FISHERIES LABORATORY. 



73 



for us to wait until high water, when the temperature 

 will have become fairly constant, in order to commence 

 pumping, owing to the somewhat limited capacity of our 

 storage tanks. 



The spawning of the fish continued for just over five 

 weeks. During that time one million two hundred and 

 twenty-five thousand plaice eggs were obtained, and 

 thirteen million six hundred thousand flounder eggs. The 

 eggs were incubated in the usual manner, and the 

 resulting fry were liberated from time to time. The first 

 batch of plaice embryos began hatching thirteen days 

 after the eggs were fertilised. The time required to 

 incubate the other batches varied from thirteen to fifteen 

 days. The incubation of the flounder eggs took from 

 nine to eleven days. The adult fish were set free in the 



Barrow Channel at the end of the hatching season. 



of eggs 



The following tables give the number 

 collected, and of the fry hatched and set free on the 

 dates specified: — 



Plaice (Pleuronectes platessa, Linn.). 



Eggs Collected. Fry Set Free. 



30,000 ... 



46,500 ... 



65,500 ... 



69,500 ... 



74,500 ... 



74,500 ... 



84,000 ... 



79,000 ... 



74,500 ... 



69,000 ... 



66,000 ... 



66,000 ... 



59,500 ... 



57,000 ... 



50,000 ... 



46,500 ... 



30,000 ... 



20,000 ... 



March 23 



.. 35,000 



>> 



25 



.. 55,000 



5> 



27 



.. 75,000 



>> 



29 



.. 80,000 



>> 



31 



.. 85,000 



April 



2 



.. 85,000 



>> 



4 



.. 95,000 



>> 



6 



.. 90,000 



>l 



8 



.. 85,000 



}} 



10 



.. 80,000 



)} 



12 



.. 75,000 



ft 



14 



.. 75,000 



>> 



16 



.. 70,000 



>> 



18 



.. 65,000 



>> 



20 



.. 60,000 



M 



22 



. 55,000 



> > 



26 



.. 35,000 



>> 



29 

 >tal Eggs 



.. 25,000 



Tc 



1,225,000 



April 



May 



12 

 16 



20 



24 



28 



"2 



6 

 >> 

 10 



>> 



12 



16 



1,062,000 Total Fry. 



