88 



SCANDINAVIAN FtSHES. 



A. W. Malm, who dcserilied it in the report of the 

 Royal Swedish Academy of Science for the j^ear 1852. 

 Mr. I. W. Grill has subsequently described, in letters 

 to li!ivSTi{i).\i, some niirmte observations on this point, 

 which wore made in Heligoland. 



Fry have thus been found of very small size. From 

 the 22iid of Julv to the 18th of August", Malm found 

 specimens IVdUi slightly over 12 mm. up to .36 nun. in 

 length, and 'Sh. Grill says that on the 25th of Sep- 

 temlicr he found 2o fry al)out 35 inuL in length under 

 a jelly-fish about 16 cm. in diameter. Generally only 

 few, from 3 to 7, are found under tlie same jelly-fish. 

 If removed from the jelly-fish and thrown into the 

 Avater neai- it, they at once endeavour to I'egain their 

 jiiding-place, and at the apjiroach of danger they creep 

 close to the disk of tlie jelly-fish among its threadlike 

 organs. Like all very small fry, they are at first quite 

 unlike the adult fish, being short, with a high head of 

 peculiar shape and with tlie mouth turned upwards. 

 Until they are about 20 mm. long, the greatest depth 

 of tlie body exceeds tlie length of the head; but when 

 they ai-e no more than 70 mm. long — at this age 

 they have left the jelly-fish — they have become normal 

 in this respect, the greatest depth of the bod}' being from 

 about 84 to 82 % of the length of tlie head. The plates 

 of the lateral line first appear, though indistinctly, in 

 si)ecimens from 1 5 to 20 mm. long; afterwards they 

 become more distinct and the lateral carinre appear. 

 In •\'<)ung specimens 35 mm. in length these parts of 

 the body have quite the same form as in the fullgrown 

 fish. Shortly after the fry have attained this size, in 

 September (or later?), they apparently leave the jelly- 

 fish and live independently, in company with young 

 Herrings and Sprats. Scads of this kind from 75 to 100 

 mm. in length, are fairly common late in autumn, when 

 they are taken with other fish in the seine. 



During sunuuer the Scad is lean, but in autumn, 

 when it conies near shore, it is fairly fat and the flesh 

 is but little inferior to that of the Mackerel either in 

 quantity or in quality. 



No special method of fishing for the Scad is prac- 

 tised in Sweden: it is onlj' occasionally taken in seines 



drawn for other fishes. This is also the case in the 

 west of the Baltic, whei'e the Scad occurs, but probably 

 goes no further east than the coast of Mecklenburgh. 

 In the Baltic, too, it is generally taken singly, though, 

 according to M«")bius and Heincke, it is sometimes, in 

 autumn, met with in shoals. Thus in November, 1872, 

 about 32,000 Scads were taken in the Bay of Eckern- 

 forde. A similar occurrence has happened in Norway, 

 too, where, accoi'ding to Collett'r assumption, the 

 Scad goes at least as far north as Trondhjein Fjord. 

 It appeared there in large shoals in the summer of 

 1862 and came up the fjords between Stavanger and 

 Bergen. It sometimes appears in still larger shoals on 

 the English coast. Oft" Glamorganshire, on the 29th of 

 July, 1834, in the evening, the whole sea was so full 

 of Scad that the surftice seemed in a state of fermen- 

 tation; and these enormous shoals continued to pass 

 up the Bristol Channel for a week*. In mid-ocean, too, 

 it collects in shoals at the surface, but generally near 

 some reef", as on the Josephine Bank, between Portu- 

 gal and the Azores, where at midsummer the Swedish 

 expedition of 1869 fell in with numerous shoals of 

 Scad, on which the gulls feasted greedily. 



In the Mediterranean and the Atlantic outside it 

 two varieties have been distinguished from tlie northern 

 Scad'', which, however, occurs there also. Thus Malm 

 gave the northern form the name of Trachurus Linnet 

 and characterized it as having at most 79 comparatively 

 high plates on the lateral line. According to Lutken, 

 the one of the Mediterranean forms, Trachurus medi- 

 terraneus, is distinguished by from 79 to 92 (according 

 to Steindachner, from 79 to 86) similar, but lower 

 plates. In the other, Trachurus Cuvieri, in contra- 

 distinction to the two forms just given, the straight, 

 posterior part of the lateral line is said to be shorter 

 than the anterior part or at most equal to it, -while 

 there are from 93 to 108 plates of average height on 

 the lateral line, and the ventral fins are exceptionally 

 short in comparison with the pectoral — in old spe- 

 cimens scarcely more than Vs of the latter in length. 

 These differences evidently run side by side Avith well- 



known changes due to age. 



The height of the lateral 



« Cf. G/jgs, Boh. Fn., p. 452. 



' Yabreli., Bi-it. FifJi., cd. 1, voL I, p. 155 and Day, I. c, p. 125. 



' See the Magazine Framtiden, 1870, p. 348, note. 



'' Cf. LVTKEN, 1. c. 



* Caran.t Cuvieri, Lowe, Trans. Zool. Soc. Lond., vol. II, (187.3) p. 183, according to him = Sei-iola pictwata, Bowdich, E.mirs. 

 Madeira (1825) p. 123, iig. 27. 



