410 



Part III. — Twentieth Annual Report 



It will be seen that at Aberdeen the year-old haddock is, on the 

 average, about 7|- inches long and weighs nearly two ounces ; when two 

 years old it measures about 1 If inches in length and weighs almost half 

 a pound; and when three years of age it is nearly fifteen inches long and 

 weighs over a pound. The deep-sea haddock is smaller and weighs less 

 than the inshore fish of corresponding age until it is about three years old, 

 when it is, according to these measurements, slightly larger ; but the 

 observations with regard to the large fish, as already stated, are less 

 complete. 



^Mth regard to the age at which maturity is reached, the observations 

 which have been made respecting the average size at first-maturity have 

 not been very extensive. On the East Coast of Scotland males have 

 been found ripe at twelve inches and females at fourteen inches, and 

 females nearly mature at twelve inches.* Holt found that the average size 

 at which the female begins to spawn was about 13 or 14 inches. He says 

 the largest immature and the smallest nearly mature females measured 16 

 and 1 1 inches respectively, and the smallest fully mature specimen 1 5 inches ; 

 all males less than ten inches were immature, and all those above twelve 

 inches were mature, or nearly set The haddocks which were caught ofi" 

 the Shetlands in March and brought to the Marine Laboratory were 

 gutted, except the smaller ones, measuring up to about twelve inches. I 

 found no ripe or nearly ripe females among those examined, and the 

 males were also immature up to 290 mm., which was the largest 

 ungutted. 



Considering these facts, and looking at the curve of measurements 

 (Plate XXI.), it may be said that while some haddocks may reach or exceed 

 the minimum size at maturity when they are two years of age, it is evi- 

 dent the great majority do not spawn until they are three years old, 

 and it is probable that none do so before they are about that age. At 

 Aberdeen the average size when three years old is approximately 15 inches, 

 while the apparent range of size in the series is from about 13 to 16| 

 inches. 



The appended Tables give the partievdars of the series of fishes dealt 

 with : — 



* Tenth Ann. R^p. Fishery Board for SroL, Part iii., p. 239rt. 

 t Journ. Mar. Biol. Asm:, iii., 80. 



