4 DEPARTMENT OF THE NAYAL SERVICE 



6 GEORGE V, A. 1916 



yet been taken in the surface nets at sea In the same year. Professor 



Mcintosh examined two samples of ripe eggs of the halibut * * *. The fertilized 

 eggs have not yet been obtained, nor any of the larval or very young stages " (up to 

 1892). 



In " The Life-histories of the British Marine Food-fishes " by W. C. Mcintosh 

 and A. T. M.asterman (London, 1897, p. 316), it is stated that: "On the coast of 

 Sweden the spawning season is given as from June to August. On the [Atlantic] 

 shores of North America it lasts till September." On the contrary there are some 

 indications that on the Pacific coast the halibut is a winter-spawning fish. Firstly, 

 there is the conspicuous absence of spawning female halibut from the usual summer 

 catches. If there had been clear evidence of spav^'ning during the experimental hauls 

 made by the Albatross in the summer of 1911, notice would have been taken of it. 

 Only in one instance, on July 20, was it mentioned that the eggs " had the appear- 

 ance of being well developed." I have found the same range of maturation phases 

 during the months of May (west coast of Queen Charlotte islands and Hecate strait) 

 and August (gulf of Alaska), the final stage, ripe for spawning, being always lacking. 

 Of course this might be due in part to the circumstance that the female halibut, like 

 the plaice, does not feed much during the spawning period, and consequently will 

 not readily take the bait. But the possibilitjv of retirement into deeper water (between 

 150 and 200 fathoms) for the purpose of spawning has to be remembered. It is a 

 curious fact, however, for which there is no accounting at present, that the larger 

 fish are to be found within the 3-mile limit, amongst the rocks in 15 to 30 fathoms, 

 and again at the outer edge of the continental shelf, whilst smaller fish occur in 

 schools on the intervening banks. Here it may be remarked that dory-fishing is best 

 adapted for the inshore zone, line-h.auling for the deep sea. 



Captain Holmes Newcomb of C.G.S. Malaspina, under date September 6, 1914, 

 has furnished me with the following information regarding the question of halibut 

 spawning. He writes: ''During the year 1913 I examined from 250 to 550 fish per 

 month ; from 28th February to 1st October I found no ripe fish. I took the best 

 samples I could get each month from the best developed fish, averaging from 40 to 

 50 pounds. These samples were collected from all over the coast; I still have them, 

 and you are welcome to them if of any use. My own opinion is that these fish spawn 

 during the fall and winter months, say from tlie latter end of October to the first or 

 middle of February." 



At Ucluelet on July 16, 1914, I obtained a female halibut weighing 36 pounds, 

 estimated from the scales to be about 10 years old, whose ovaries appeared to be in 

 a spent condition, but after preservation in 10 per cent formalin, the^y proved to be 

 regenerating, and might well have been spent during the previous winter season. It 

 is the only example of the kind that I observed. How long it takes for a halibut to 

 regenerate after spawning is entirely unknown. The estimation of the age of this 

 specimen is based on a comparison with the figures published by Prof. Playfair 

 McMurrich in his " Notes on the Scale-markings of the Halibut and their bearing 

 on questions connected with the conservation of the fishery" (Trans. R y. Sec, 

 Canada, series 3, vol. vii, sec. iv, Ottawa, 1913). 



It is quite probable that the spawn and fry of the halibut are to be sought for in 

 the deeper layers of water; in other words, that they are bathypelagic, and therefore 

 will not be taken in the surface tow-net. The newly hatched halibut larva has never 

 }>een obtained. The first recorded post-larval stage was described in 1893 by Dr. C. G. 

 J. Petersen (" On the Biology of our Flatfishes," Eep. Danish Biol. Station iv, 1914, 

 pp. 1-146, two pis. See p. 130 pi. ii, f. 20) whose work I have not seen. His figure of 

 the young pelagic stage is reproduced by Mcintosh and Masterman (op. cit. pi. xii, f. 

 10). The specimen was 32 mm. long; the migration of the left eye had hardly begun, 

 and the fin-rays were absent from the pectoral and ventral fins. 



The only other alleged post-larval stages that had been examined before 1900 were 

 two young pleuronectids taken in the bottom net in the Moray Firth in August, 1896. 



