APPENDIX G 



18 — 



Hens en has made the endeavour to determine the quantity of the spawning fish by counting 

 their eggs, but this has proved to he impossible up to the present, partly owing to the 

 lack of uniformity in the distribution of the eggs, arising from the currents and the distribution 

 of the spawning fish. 



On the other hand, it has been shown that the study of the distribution of the earliest 

 pelagic stages gives us a means of determining the distribution of the spawning fish-shoals, 

 and this study had the double importance: on the one hand, of finding new spawning-grounds 

 (e. g. fishing-grounds) and on the other hand, of giving a view over the geographical extension 

 of the spawning-region of a species. The solution of these problems by fishery experiments 

 in search of the large spawning animals only, would have been connected with much greater 

 difficulties. 



Thus, the investigation of the pelagic young stages has the double importance of ascer- 

 taining the distribution of the spawning fishes and the fate of the eggs spawned. We shall 

 display what may be reached in this direction by some examples. 



a. The young stages of the genus Gadus (cod group) 



On the south coast of Iceland, Schmidt^ has investigated the distribution of the eggs, 

 pelagic larvae and young fishes at various distances from the coast (Ingolfshöfde), and has 

 found that the small larvae and young fishes which come from demersal eggs, were floating in 

 the immediate proximity of the coasts; further out, he found the larvse of the pelagic eggs, 

 and still further out beyond the coastal banks, the larvae of the purely pelagic, viviparous 

 fishes. Particulars are shown in the following table: 



During the 1st and 2nd of June 1903, the fishing was carried on at each station at 

 the surface for 5 minutes with the pelagic net and 10 minutes with the pelagic trawl. 



Distance from the coast 



4 nautical 

 miles 



10 nautical 

 miles 



23 nautical 

 miles 



.54 nautical 

 miles 



57 nautical 

 mUes 



95 nautical 

 miles 



Depth in meters 



Total number of pelagic eggs . 

 Total number of pelagic larvae 



Percentage of pelagic larvœ from 



Demersal eggs 



Pelagic eggs 



Pelagic viviparous fishes 



32-70 



300—400 



3 



100 "/o 

 

 



100 

 291 



93% 

 7»o 

 



106 



3 



182 



67°/o 



33% 







1044 

 

 50 







100 "/o 







over 1080 

 

 50 





 



100 "/o 



1440—1880 







300 











100 "/o 



From this example it appears, that the larvae and young fishes which come from pelagic 

 eggs, are to be found further away from the coast than the larvae of the demersal eggs. The 

 further study of the fate of the pelagic young fishes proves that the duration of the pelagic 

 stage is different for each species. This can be exemplified for the most important species of 

 the genus Gadus especially. 



Jobs. Schmidt, Piskeriundersogelser ved Island og Paeroerne i Sommeren 1903. 

 Kommissionen for Havundersogelser, Nr. 1, p. 41 (Dansk), Kebenhavii 1904. 



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