13 



The following year, 1867, young cods were also observed under 

 the jelly-fishes towards the end of July. By later examining the 

 stomach contents of large green-cods, these fishes proved brimful 

 of fry both of cod and, green cod, but the contents were generally 

 so dissolved, that a careful examination could not be undertaken. 

 The young cods, however, thus obtained, were found to be larger 

 than those that sought the protecting company of the jelly-fishes. 

 The matter was now to seek for the haunts of the green cod; for 

 where this fish stayed its food must also exist, and the latter, as 

 already mentioned, consisted chiefly of young cods. As a curiosity 

 may be mentioned that a live young cod, 80 mm. long, was taken 

 from the stomach of a green cod. 



During the continued pursuit of the young cods, Saes discov- 

 ered (August 3rd) that a whole lot of them had taken refuge among 

 floating bits of sea-weed and other objects driven together by the 

 current. He succeeded in catching some of them. The length was 

 50 — (50 nim., with a fine colouring, a developed barbal thread, and 

 with the fins arranged as in the grown-up individuals. On August 

 23rd a rich catch was made of young cods, which now swarmed 

 along the shore. The stomach contents consisted of Crustacea, as 

 gammanis lorusta, annelides, &c. It further came to be seen tliat 

 in the course of September young cods were found at different 

 places along the shore, but the length of these continually kept at 

 60 — 70 mm. As there was no reason to believe that at that period 

 there should be any hindrance to the growth, because in the belt 

 of sea-weed there was sufficient food, Saes formed the opinion that 

 it then was a period of immigration to. and an emigration from, 

 the littoral region, which consequently only served as a temporary 

 ■staying ground for the young cods. As the spawning does not 

 occur contemporaneously, the migration to the sea-weed belt will 

 be extended over a period that depends on the lasting of the 

 spawning time. 



By fishing experiments at the beginning of Octolier. the older 

 young cods (120—130 mm.) were found at a greater deptli, and 

 their age was put at about 7 months. In the following year, 1868, 

 Saes caught at the beginning of December young cod whose size 

 varied between 150 — 200 mm., at the depth of 8— 12 fathoms, near 

 Skraaven. These had their stomachs brimful of sea animals of 

 different kinds, chiefly Crustacea, as shrimps, crabs, and amphipodes. 

 In the colouring there was great variation, even the form of the 

 body was subject to considerable changes. Two principal types, 

 however, coidd be distinguished, one thick and short, reddish form, 

 comprising the individuals that had stayed on see-weed bottom, 

 whose rich fauna of Crustacea served it for food, and a greenish 

 or greyish form, distinguished by a more slender structure of the 

 body. These latter ones had chiefly stayed on sandy bottom, 

 the animal life of which is poorer. In the stomachs of such individuals 

 were also found different Crustacea and young fishfrogs (cotius 

 scorpius). By setting out a sink-line near sea-weed grounds at 

 some distance from the shore, Saes caught a lot of small cods, of 

 the length of about 1 foot (314 mm.). A few larger individuals 

 also occurred, whose age was put at 2 years. 



f ! Mr. Saes. by careful examinations, formed the opinion that 

 the main mass of the young cods that live during spring and autumn 

 'on the sea-weed ground is made up of last year's fry. That the 



sea-weed cod in Lofoten is the fry of the ocean cod seems to be 

 quite certain from the investigations of Saes. There further occurs 

 in Lofoten, especially at the beginning of the fishing, a cod-form 

 called "opsigfisk" or "egfisk". It is thus described: "The form 

 of the body is thicker and more clumsy than in the ocean cod 

 proper; the head is not so pointed, the back of the neck is com- 

 paratively broader, the predominating colour has a distinct brownish- 

 yellowish tinge, the dark spots were more numerous and reached 

 farther down the sides than in the ocean cod, the teeth were also 

 considerably smaller and fewer in number." It is further remarked 

 that the "opsigfisk" consists of sexually ripe individuals. By very 

 careful comparisons, Saes foimd that transition forms existed between 

 the two; that none of the special distinguishing marks of the "op- 

 sigfisk" could be considered as constant, and that the existing 

 difference must be considered as derived from accidental circumstances, 

 as food and staying ground. Saes has stated the opsigfisk to be 

 the stationary cod form of Lofoten, and this is no doubt correct. 

 It would not agree with the tendency of nature to utilize space if 

 all the fry developed in Lofoten should emigrate to the ocean banks 

 and the edge. Nor is the thing so simple; the majority certainly 

 emigrate, but a smaller part also find themselves provided for on 

 the inner banks and the inner edge, where particularly the larger 

 individuals are staying. Here they develop to sexual maturity, 

 and therefore at the beginning of the fishing appear at the fishing 

 stations as opsigfisk. 



Thus the principal features of the post-embryonal life of 

 the ocean cod are as follows : It is difficult for the new-hatched fry 

 to undertake greater movements on account of their comparatively 

 large yolk-sac, they keep to the surface of the water, and are 

 subjected to the motions of the surface water. After the yolk- 

 sac has been absorbed, and the power of moving about has 

 increased, they move into deeper water, but they must still be 

 classed to plancton organisms, and their food during this time is 

 solely of planctonic kind. According to my plancton tables the 

 food during the first time is not much varied; it seems chiefly to 

 consist of larvae of copepods, annehds, and echinoderms, together 

 with young specimens of calamus finmarchieus, oithona similis, &c. 



The young fish, having towards the end of the summer reached a 

 lenght of 26 — 30 mm., begin moving towards land in order to take 

 up a more stationary way of living, and the transition from the pelagic 

 life to a littoral one is mediated, according to Saes's investigations, 

 by a symbiosis with the jelly-fish. That however a great deal of the 

 fry skip over this intermediate stage and move directly towards the 

 shore, seems likely, as jelly-fish scarcely occur in such numbers, that 

 these millions of tiny cod can find hosts. The strange circumstance 

 that the young cod at a certain period seek company with the jelly- 

 fish, must problably be explained by the instinctive craving for a 

 hiding-place. In the transition period between pelagic and littoral life, 

 they are therefore also found among drifting objects crowded' to- 

 gether by the current, and partly occur in great masses swarming 

 round the outer skerries and rocks, where they are unsparingly 

 pursued l)y green cod, sea-gulls, &c. Gradually they then move 

 up into the rich crustacean world of the sea-weed belt, which they 

 once more leave in order to seek the submerged rocks and sea- 

 weed grounds of the fjord. While one part is left to stay on the 



