of tine Fishery Board for Scotland. 



193 



214 mm. This would give a range in size of 87 mm. or 3j^^ inches, and 

 an average size for the thirty-six specimens of 161 "5 mm. or 6|- inches, 

 the maximum being about 8| inches and the minimum 5 inches. In that 

 case the two specimens of five-and-a-half inches caught in March and 

 April would be under the mean size — as, of course, they might well be. 

 The haddock, it may be said, whose main hatching or larval period is 

 about the early part of April, attains on an average a length of close upon 

 seven inches (169-6 mm.) in November, the ascertained range, from many 

 hundreds of specimens, being from 127 mm. to 220 mm.* The spawning 

 of the angler is later ; but, on the other hand, the adult is very much 

 larger than the adult haddock and its growth ought to be quicker, and 

 unless the transformation stages of the angler cause considerable 

 retardation of growth in length, the sizes above given probably represent 

 approximately the real sizes at the period. The end of the group, 

 however, may possibly be at 180 mm., or about 7J inches. On that basis 

 the calculated mean size would be 10 mm. less — viz., 151'0 mm., or a little 

 under six inches. It is also to be borne in mind that the smallest 

 anglers of the true natural series are probably absent. 



The second series in the November specimens begins apparently at 

 235 mm., there being none between this and 214 mm. The specimens at 

 the different sizes are somewhat irregular in numbers, but the end of the 

 group appears to occur at 402 mm. or 15i| inches, the average size being 

 about 318 mm. or twelve-and-a-half inches. This would represent a 

 mean-growth in a year, from the average of the first group, of a little over 

 six inches. The series may, however, end at 380 mm., in which case the 

 mean-size would be about 30*5 cm. or twelve inches. 



If we turn now to the next best series of measurements, that for the 

 end of July and beginning of August, it will be seen that the first series 

 represented begins at 19 cm. — 192 mm. — or at a little over seven-and a- 

 half inches. Its termination is less clear, but seems to be at 315 mm. — 

 it might be 306 mm. The mean-size of the series is by computation 

 252'5 mm., and by the graphic system 250 mm., or about 9g inches. On 

 the basis above stated, this would indicate a growth of the same series 

 from the November preceding of about 90 mm. or three-and-a-half inches 

 — that is to say, in the months December-July — and a growth to the 

 following November of about 68 mm. or 2| inches, that is in August, 

 September, and October, the aggregate being about six-and-a-quarter 

 inches, which fairly corresponds. 



The second group at the beginning of August begins at 319 mm. or about 

 12| inches, and appears to extend to 495 mm. or nineteen-and-a-half 

 inches, the mean-size being about 40*5 cm. or sixteen inches. The fish in 

 this series may be regarded as about two years and three months old. 

 The average increment in a year as computed from the average of the 

 previous series amounts to about 15*5 cm., or a little over six inches, 

 which also approximately corresponds with the increment deduced from 

 comparison of the averages in the previous cases. Compared with the 

 second series in November, there is a difference in the mean-size in the 

 two cases of 87 mm., or nearly three-and-a-half inches, which represents 

 approximately the amount of growth from November to the beginning of 

 August. The facts seem to show that the growth of the angler is more 

 regular throughout the year than in the case of the haddock, whiting, 

 plaice, and dab, being less retarded in winter and less accelerated in 

 summer. This is what might be expected in a fish inhabiting, as a rule, 

 water of some depth, where the temperature changes at different seasons 

 are less pronounced. 



* Twentieth Annval Report, Part III., p. 402. 



