26 Fishery Board for Scotland. 



It has already been noted that most of the eggs were taken in the surface tow- 

 nets. All were captured, however, in the northern North Sea, north of 57° Latitude. 

 It has been impossible to express within the limits of a single chart the number 

 of times the various localities have been visited within the eleven years under 

 observation. Even from Chart II., however, it can be seen that the stations south 

 of 57° North Latitude have been visited very frequently at all periods of the year. 

 The negative records from these stations are, therefore, of considerable importance 

 in dealing with the distribution of these isolated eggs, which, if present, could have 

 been so readily caught in the tow-nets. 



The Spawning Period. 



Fulton (1902) discusses the spawning time of the Angler from the e^^.dence of 

 the occurrence of the ripe adult. On the east coast of Scotland, the males are 

 apparently earlier than the females. A ripe male was got off Lossiemouth on the 

 3rd November, and on the 20th and 24th December two ripe males were obtained 

 at Burghead in shallow water. He also quotes Holt as having found a ripe male 

 25 inches long in 115 fathoms, in March. Females apparently almost ripe, with 

 very large ovaries were taken in February, on the east coast of Scotland, and Holt 

 found spent females of 30 inches in length in June, and one of 40 inches in March. 



The times of occurence of the sheets of spawn and of the isolated eggs give much 

 more definite information regarding the duration of the spawning period. This 

 period appears to be an extended one. On the Scottish coast, one sheet of spawn 

 was obtained off Kinnaird Head on 18th February, and another, in which the 

 embryos were far advanced, was obtained in Aberdeen Bay as late as 1st Augu.st. 

 The record from 57° 37' N. ; 0° 53' E., made on 4th May"l916, is the only one in 

 which the eggs were in the initial stages of development. Isolated eggs were cap- 

 tured as early as 18th March 1914. On that date, five eggs, in which there were 

 no signs of developing embryos, were obtained at 57° 57' N; 3° 10' W. Again, 

 on the 31st March 1905", at 58° N. ; 2° 54' W., there were taken fifty-three isolated 

 eggs of LopJiius, in which the embryos were very far advanced in development ; 

 in fifty of these, the embryos stretched two-thirds round the yolk, and were thus 

 almost ready to hatch out. One must conclude, from the appearance of these 

 eggs so far advanced in development at that time of the year^ that they must have 

 been spawned very much earlier. On the other hand, isolated eggs, captured on 

 the 5th July 1913, showed no traces of developing embryos. 



These records, therefore, show conclusively that the spawning period in Scottish 

 waters begins as early as February, and extends at least to the first weeks in July. 



Ehrenbaum (1905) does not add any original information to our knowledge of 

 the spawning period, except that eggs were obtained by him in the Skagerrak in 

 the beginning of July. In his tables of the plankton eggs of fishes occurring in the 

 North Sea, he restricts the spawning period to the months June, July, and August. 



Aoassiz and Whitman (1885), from the American side of the Atlantic, state 

 that the floating eggs of Lophius have been obtained early in June and late in 

 August, and Murray and Hjort's record for 29th June is in agreement. 



The two samples of spawn, got by Lo Bianco in the Mediterranean on 21st 

 January and 27th February, show that spawning in that area is very early. In 

 both cases, embryos were well developed in the eggs. 



The statements by Stiasny and Graeffe, regarding the spawning season for the 

 Mediterranean fish, must be taken with great reserve. Neither of these authors 

 gives actual records of the occurrence of the eggs, but they deduce the time of 

 spawning from the capture of the post-larval forms. Graeffe (1888) gives the 

 spawning period as December and January, because young forms are found swim- 

 ming pelagically in the sea in the months of February, March, April. His remark 

 that he believes the eggs may be pelagic, suggests that he did not know the eggs of 

 the Angler. 



Stiasny (1911) mentions that the eggs of Lophius have not been observed m 

 the Gulf of Trieste, but suggests that the frequently-occurring adult probably 

 spawns in the winter months. This conclusion is based on the time of occurrence 

 of the post-larval forms, and its vaHdity will be considered later. 



The time of spawning given for the Mediterranean fish does not conflict in any 



