190 



Fart III. — Fifteenth Annual Report 



The Haddock. 



The development of the eggs of the haddock was given by Professor 

 Prince and the author, in the ' Researches/ * and the characters of the 

 larval form indicated. The latter was chiefly recognised by the eyes, 

 which are large and pigmented, by the blackish pigment on the head, 

 by the deep band of pigment on the dorsal arch of the abdomen, and by 

 a faint line below the muscle-plates of the same region. The larvae are 

 small, — about 3 mm. in length on hatching. 



While the larval and earlier post-larval stages of the haddock have 

 thus been fully elucidated at the St Andrews Marine Laboratory, the 

 later post-larval and very young stages have hitherto eluded observation. 

 Professor G. 0. Sars, it is true, held that the post-larval haddock could 

 be recognised amidst the swarms of young fishes on the spawning-grounds 

 of Lofoten, and in this he was probably correct, though very considerable 

 uncertainty existed. A re-examination of the whole question this year 

 shows, as has been more than once pointed out at St Andrews, that the 

 later post-larval and early stages of the adolescent haddock altogether 

 diverge from those of the cod in regard to their haunts. The young 

 cod, as shown in the preceding pages, gradually pass shore-wards, and 

 when about an inch in length, approach the margin of the rocks, where 

 they swim amidst the tangle-forests, and enter the tidal runlets for a 

 considerable time. The haddock, on the other hand, at the stages 

 mentioned, keeps to the offshore water until it has assumed a readily 

 recognisable or adolescent condition. 



The following is a succinct account of the various stages : — 



Whilst the marginal fin is still continuous, the black pigment of 

 these shorter forms of 7 to 8 mm. from the offshore water — probably 

 the same as .those mentioned by Professor G. 0. Sars, is scattered 

 over the head, along the dorsal and ventral edges — with a few specks 

 on the sides posteriorly. At 11 mm., besides the foregoing colora- 

 tion, a very distinct area of pigment-points occurs behind the pectorals. 

 A few specks also appear on the latter and on the ventrals, which 

 at this stage form short fins with true rays. True fin-rays are now 

 present in the second and in the third dorsal (the marginal fins being 

 still continuous), in the two anal and in the caudal fins, but the first 

 dorsal has only embryonic rays. The body is comparatively short 

 and thick, and the head large. The food consists of young copepods. 

 At 12 5 mm., the marginal fin is likewise continuous with the caudal. 

 True fin-rays are developing in the first dorsal. Such stages do not, so 

 far as at present known, occur in numbers inshore, but frequent the 

 fishing banks offshore, especially in May. Instead of seeking their way 

 inshore, indeed, like the cod and green cod, the little haddock frequent 

 the deeper water offshore, and they are found in great numbers, for 

 instance, 25 to 30 miles east by south of the Island of May, and near 

 the fishing grounds termed by the liners the 'Long Forties.' There the 

 large mid-water net captures them, in the first weeks of July, along with 

 swarms of young whiting, and ranging in length from 24 to 80 mm., as 

 well as, in all probability, on both sides of these dimensions. 



At 19 mm., the outline is short and thick-set, and the fins are well 

 developed. The ventrals are lengthened ; their long sensitive tips pro- 

 jecting beyond the vent. The head and eye are large, and the snout 

 blunt. The only pigment left on the specimen is over the brain, but 

 probably both dorsal and ventral edges and the sides were more or less 

 coloured. 



* Trans, Roy, Soc. Min., vol. xxxv. part iii. p. 822. 



