SEA-FISHERIES LABORATORY. 



219 



Table III. Sprats and Immature Herrings. 



Date. 



Weight of 

 Sex, &c. muscle 

 ! substance. 



Dry 



weight. 



Weight of 

 oil. 



Percentage 

 of oil. 



Percentage 

 of water. 



Morecamb 

 1914 

 Mav 24 ... 2-766 

 May 30 ... 4-857 

 3-108 



3 Immature 



Herrings. 



0-085 

 0-202 

 0-101 



30 

 4-1 

 3-2 









Morecambe Sprats, Immature. 







May 29 



2-136 I ... I 0-205 

 Mersey Estuary Sprats, Mature. 



9-5 





Jan. 27 ... 5-230 1-566 0-624 



11-9 



70-0 



Table I gives the results of analysis of the summer- caught 

 herrings sent from Isle of Man. In the earlier analysis the 

 tissue was dried so as to facilitate the fat extraction, but 

 weighings were not made. Male and female fish were usually 

 taken from each sample, and the separate analytical results 

 are given. But, on looking at this and the other tables, one 

 sees no significant sexual differences, so that the means of 

 the separate estimations of male and female fish have been 

 taken in making the graph of the results. Table II deals with 

 winter-caught herrings from the Welsh Bays, and includes a 

 few results obtained in December of 1913. Table III gives 

 only a few results of analysis of small herrings and sprats 

 from Morecambe Bay and the Mersey Estuary. The herrings 

 were all immature. The Morecambe Bay sprats (almost 

 " whitebait ") were also very small. The Mersey sprats were 

 large and mature fish with gonads last approaching maturity. 

 They would probably have spawned in the spring of this year. 



The results of the tattles, as regards the Manx and the 

 Welsh fish, arc represented in the graph which follows this. 



