of the Fishery Board for Scotland. 



203 



(13|-16g inches) are not under 5| years old, and that those about 50cm. 

 (20 inches) are not under 7 \ years of age, while those between 40cm. and 

 46cm. (16-18 inches), when reproduction is supposed to commence, are at 

 least 6^ years old at the season of the year referred to, and may be a 

 year, or possibly two years, older still. 



It seems to me probable that the turbot does not spawn until it is 

 at least seven years of age. 



With reference to the slow rate of increase in length of the turbot, as 

 thus indicated, the relatively great increment in weight must not be lost 

 sight of. Thus a turbot of 44cm. (17| inches) weighs about 1830 

 grammes, and one of 50cm. (19| inches) weighs about 2700 grammes, 

 while plaice of the same lengths weigh just about half — viz., about 950 

 and 1430 grammes respectively — and a female plaice of 44 cm. is at least 

 five years of age, and may be six. On the other hand, one would expect 

 that the rate of increase of weight in the turbot would be greater than in 

 the plaice, owing to its piscivorous habit and feeding. 



BRILL (Rhombus Icevis). 



As with the turbot, so with this fish, the observations in respect to the 

 rate of growth are not as complete as they might be. A considerable 

 number of specimens were, however, measured, viz., 1182, and they appear 

 to be satisfactory as regards certain groups (Table XVIIL). 



The spawning period of the brill is about a month or so earlier than 

 that of the turbot, extending from the end of March into July, the chief 

 spawning taking place in May. The egg is larger than that of the 

 turbot, varying according to Heincke and Ehrenbaum, from l'24mm. to 

 l*46mm., and hatching occurs in twelve or thirteen days. 



The smallest specimens in my collections were procured from Aberdeen 

 Bay on 18th September, being taken on the beach at low tide by means 

 of a push-net; they numbered six, and measured as follows: — 38mm., 

 40mm., 47mm., 49mm., 51mm., and 54mm., or 1J to 2| inches. At the 

 mouth of the Forth, on the 17th September, four specimens measuring 

 41mm., 54mm., 57mm.. and 58mm., and another of 78mm., or a trifle 

 over three inches, were obtained in another year. Other small specimens 

 taken were as follows : — One at 41mm. (1§ inches), by the push- net in 

 Lochfyne on 27th July ; one measuring 51mm., on 27th July, by shrimp- 

 net at Annan, and another in the same locality on 30th April which 

 measured 80mm. (3g inches). M'Intosh mentions specimens measuring 

 from 22mm. to 29mm. in August, one of 24mm. on 25th July, and 

 others from 50mm.-61mm. in September. Cunningham records 34 

 specimens measuring from 22mm. to 25mm., between 21st May and 11th 

 June. 



All the above, with the exception of the specimen taken in the Solway, 

 measuring 82mm. (3| inches), on 30th April, were no doubt derived fiom 

 the spawning in the same year. 



Other specimens which have been described, and which apparently 

 belong to the spawning of the previous year, are as follows : — That 

 referred to above, which was 82mm. long, on 30th April ; one of 74mm. 

 (2|| inches) taken on 4th May; one of 91mm. and another of 96mm. 

 (3| inches) taken on 25th April; one of 104mm. taken on 28th April; 

 two on 15th June, measuring 89mm. and 104mm. ; and two on 14th 

 May, measuring 98mm. and 108mm. (4^ inches) — all of which are 

 referred to by Cunningham. These specimens, together with some of the 

 smaller individuals got in salmon stake-nets and referred to below, may be 

 included in the following Table ; the latter are represented by a small (x), 

 the former by a large (X) : — 



