19(5 



Part HI. — Twenty-fourth Annual Report 



Larval and post-larval lemon dabs have been obtained at periods 

 which correspond with the long spawning season. Thus, Cunningham 

 records specimens of 10mm. and over taken in April, and specimens of 

 this size are taken in May, while at the end of October they have been 

 secured in considerable numbers measuring from 8mm. to 18mm. It is 

 obvious that in the succeeding year, say in spring, the young lemon dabs 

 derived from these would vary much in size. The early ones would have 

 the full benefit of the favourable temperature throughout the whole year, 

 while those of October would meet with the colder water in winter and 

 have their growth retarded. Thus, a specimen caught by the " Garland " 

 on 7th May, which measured 25mm., was no doubt derived from the pre- 

 ceding year, while specimens measuring 27 mm. taken in August belonged 

 to the same year. 



Young lemon dabs in some number were got by Holt at the Humber 

 in October and November, measuring from 2 to 3J inches, which might 

 possibly have been derived from the spawning of that year, but the larger, 

 at least, were more probably from that of the year before. 



Cunningham, at the beginning of June, took small lemon dabs on the 

 Essex coast from 3 to 5 inches long, and these were clearly at least one 

 year old. 



The evidence seems to me to justify the belief that the growth of the 

 lemon dab is slow, and probably does not much, if at all, exceed 5cm. to 

 6cm. (2 to 2| inches) in a year. It is probable that the female does not 

 spawn before the fourth year, though the prematurely mature specimens 

 occasionally got* probably spawn at an earlier age, and may form a 

 distinct variety. 



LONG ROUGH DAB ( Drepanopsetta platessoides, Yabr.J. 



Various collections of long rough dabs were measured, the total num- 

 ber being 3529, part of them being from the Moray Firth and part from 

 Aberdeen Bay (Table XVI.). Including those dealt with in the previous 

 paper, the aggregate number measured amounts to 20,261. 



Several of the collections contained the very small series which are 

 always in this species well separated from the older series, contrasting 

 with the case of the lemon dab. The spawning period of the long rough 

 dab extends from the end of January well into May, and is chiefly 

 marked at the end of March and the beginning of April. Each year's 

 brood have therefore the summer following for growth, and not, as in the 

 lemon dab, part of them the summer and part of them the winter. 



In three collections made in the Moray Firth the early group is well 

 shown. The first was taken on 28th December in 30 fathoms, on the so- 

 called witch ground off Burghead ; the second on 23rd January, but 

 somewhat further east off Kinnaird Head, in 50 fathoms; and the third 

 on 1st April, in the neighbourhood of the place where the first haul was 

 made, in from 30 to 32 fathoms. 



In the December collection 73 fish belonged to this group; they ranged 

 in length from 46mm. to 65mm. (l-rf-2^ inches) (the next largest in the 

 collection being 85mm.), and the average length was 56 - 8mm., or 2\ 

 inches. In the January collection there were 57 specimens, ranging from 

 47mm. to 68mm. inches) (the next largest being 86mm.), and 



the average computed size was 57*4nim., or 2 \ inches. The third collec- 

 tion contained 84 specimens of the class, varying in length from 47mm. 

 to 70mm. (lg-2f inches), and the average was 56*2mm., or almost 2\ 

 inches, the next largest in the collection being 89mm. 



*See Twenty-first Annual Report, Part III., p, 48. 



