INVESTIGATION INTO THE LIFE -CYCLE OF SUMMER-SPAWNING 



HERRING OF ICELAND 



K. A. Liamin 



Herring from t±ie Iceland region were established by Heincke (7) as an independent race 

 distinguished by a number of morphological characteristics. Heincke did not know the spawning 

 time for these herring, but he supposed that spyawning occurred in spring or summer. 



Saemundsson, one of the first Icelandic ichthyologists, was the first to bring to light spring- 

 spawning and summer-spawning herring in Iceland waters.— 



Extensive researches on herring larvae in the Iceland region were carried out at the begin- 

 ning of the present century by the Danish scholar I. Schmidt on the expedition ship 'Thor' from 

 1903 to 1908. 



On the basis of his own observations and I. Schmidt's data, Saemundsson established the 

 periods and regions of spawning of the summer race herring off Iceland.—' 



Jespersen (13) worked over the material collected by Schmidt from 1903 to 1908, analysed 

 the distribution of the larvae, taking into account their length and the periods when they were 

 caught, and confirmed Schmidt's and Saemundsson's conclusions that there were summer -spawning 

 herrings in the waters of Iceland. 



From the distribution of larvae of the early stages (less than 10 mm. in length) Jespersen 

 established that the spawning region of the summer race lay in the waters off the southern coast of 

 the island during July through August. 



Exploiting the researches of Saemundsson, Schmidt, and Jespersen, Johansen (11, 12) pro- 

 duced the first plan of the migrations of the summer -spawning herring, according to which the 

 spawning of this race takes place along the south coast while the fattening-up region lies to the 

 north of the island. 



From 1924 to 1934, considerable research on the distribution of the larvae of the herring 

 was carried out by Taning (17). In subsequent years (1939, 1946, 1950), he also carried out re- 

 search on board the "Dana" off Iceland from July through September, and this enabled him to collect 

 a large amount of material on the larvae of the summer -spawning race. 



In a report on the Icelandic herring which came out in 1944, Fridriksson (4) summed up the 

 results of the many years of herring research in the region of Iceland. Fridriksson confirmed the 

 conclusions of all previous investigators that there were summer -spawning herring in Iceland 

 waters. At the same time, the author of the monograph comes to the conviction that the summer 

 race is not very numerous. Fridriksson determined that the summer -spawning herring accounts 

 for 1.2% of Iceland's herring fishery. 



\_l See Fridriksson (4). 

 2/ " 



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