508 AN EXPERIMENT IN THE TRANSPLANTATION OF PLAICE FROM 



Although the above lists are not exhaustive and the growths 

 quoted have been taken more or less at random, it can be clearly seen 

 how slowly North Sea plaice of the stated lengths grew, as compared 

 with these fish transplanted from the White Sea. 



As compared with the first transplanted plaice only two growths 

 of North Sea fish are noticed to be in excess, and these individuals 

 had been at liberty respectively twice and three times as long after 

 marking. 



Comparing the growth of E 3880 with that of similar sized North 

 Sea fishes, we find it only surpassed by specimens which have been out 

 tioice, nearly thrice, four and a half, and nearly six times aslong. 



No growth is observed to equal that shown in the case of E 3884, 

 3893, or 3875, though some of the periods of liberty are more than 

 twice as long. 



These growths are truly remarkable, in consideration of the prob- 

 able age of the specimens concerned, and in view of the slow growth 

 old plaice have been frequently shown to display. 



It may be mentioned that further, but incomplete, investigations 

 of the otoliths of the smallest plaice yet found on the White Sea 

 grounds amply bear out the indications of slow growth afforded in my 

 earlier report. 



2. Increase in Weight. — All the fish have been weighed after 

 their recovery by the fishermen, but, as the relation between length 

 and weight of White Sea plaice in their normal condition is unknown 

 at present, it is not possible to state exactly by how much the last five 

 individuals have increased their bulk. In view of the additions which 

 have been demonstrated as regards length, and in view of the fattened 

 condition of the fish, the weight increments must have been very con- 

 siderable. A tentative estimate can be deduced from the following 

 data. 



The weights of the eight fish caught in July compared with the 

 average weight of Dogger plaice of the same sizes determined by 

 Masterman* show deficiencies amounting to 17"3, 23'5, 415, 38"1, 29'1, 

 31*0, 22'9, and 26"8 per cent respectively. The average deficit amounts 

 to just under 29%. 



It cannot at present be said how closely this determination displays 

 the actual deficiency in condition for which the White Sea plaice are 

 noted, but it at least has the merit of bearing out the experience of 

 practical men as to the inferiority of these fish as compared with 

 those from the North Sea. 



* Report on the Research Work of the Board of Agriculture and Fisheries in relation 

 to the Plaice Fisheries of the North Sea. Cd, 4738. London, 1909. 



