354 



REPORT ON THE PROBABLE AGES OF YOUNG FISH. 



Probable age. 



10 to 13 months 



2 years 



1 year 



2 years 



Locality and mode of capture. 



Cleethorpes Sands ; cart- 

 trawl. 

 Cleethorpes to Humber- 

 stone ; cart-trawl. 



-Humber; shrimp trawler, 



3 years '^ 



10^ to 13-J- monthsi Cleethorpes Sands ; shove- 

 I net. 



2 years 

 11 to 14 months 



1 year 

 llA to 14i months 



Humberstone Sands ; 

 shove-net. 



Y New Clee ; shove-net. 



1 Mouth of Humber, 



I Tetney ground ; shrimp 



}■ trawler's whole catch 



I for night ; no fish 



J returned to sea. 



Tetney Sands ; shove-net. 

 Cleethorpes Sands ; shove- 

 net. 



The most interesting feature of this collection is the absence of 

 soles small enough to be referred to the spawning season of the 

 same year. Mr. Holt finds that in the North Sea the spawning 

 period of the sole coincides with that of the brill, but that it is not 

 quite over till the beginning of August. Therefore, it begins at 

 the end of April, goes on chiefly in May and June, and rare indivi- 

 duals are found spawning in July. The smallest specimens obtained 

 are 2| to 2| inches, 6'0 to 6'4 cm. long, and were taken in the 

 shove-net on Cleethorpes sands in April, May, and June. These 

 could not be less than nine or ten months old, and may have been 

 more, so that some soles grow as slowly under natural conditions as 

 some of the flounders which I have reared in captivity. These soles 

 of the previous year's brood were taken chiefly in the shove-net or 

 the cart-trawl quite close to the shore, very few appearing in the 

 produce of the shrimp trawlers. The sole is somewhat larger than 

 the flounder, and we may reasonably suppose that 8 inches is about 

 the maximum length attained in one year's growth. The total num- 

 ber of specimens obtained which were less than 8 inches long is sixty- 



