856 



SCANIJINAVIAX FISHES. 



adopt tlieir briglit dress. The Parr markings and the 

 red spots slowly disappear, and the sides of the body 

 at tiie same time exchange their orange ground-colour 

 for a brighter and brighter silvery lustre, caused by 

 the depositing of a silvery pigment on the inner sur- 

 face of the scales and opercula. Now, and not until 

 now, do tlie scales begin to be quite distinct. Young 

 Salmon of this age are known in England as Smolts. 

 Great irregularity, ho'wever, may be observed in the 

 growth of these Parrs and the consequent alteration of 

 colour. At Stormontfield, among a brood excluded from 

 eggs impregnated at the end of December, 1861, and 

 hatched in April, 18()!2, were found on the 1st of April, 

 1863", some specimens 54 mm. long and V'^ grammes 

 in weight, others 92 mm. long and 3'., grin, in weight, 

 and others 165 mm. long and 37'/^ grm. in weight. 

 Only tiie last were Smolts, and these would probably 

 have migrated to the sea the same season, the others 

 not until the following year or even the year after 

 that. 



Tlie alteration in the colouring of young Trout 

 after the Parr stage is genei'ally not great, provided 

 tiiat they belong to a race wliich is either unal)le or 

 has no inclination to enter salt water. They assume 

 a dress in which they are known as Foreller (Eng. 

 River Ti'out, Common Trout), and which they may 

 retain in small, land-locked waters almost unchanged 

 tlu'ougiiout their life. Under these conditions their 

 growth too is inconsiderable, v. Wkights iigure (Plate 

 XL, fig. 2) represents a common Scandinavian Forell. 

 The orange ground-colour of the sides and the red 

 spots on the lateral line — each surrounded here by a 

 more distinct, liglit ring — are persistent; and both 

 above and below the lateral line there appear similar 

 spots, scattered over the sides of the body'. At the 

 same time the number and extent of the dark (Ijlack) 

 spots on the back and head are generally increased, 

 these spots now occurring even down the sides, while 

 the Parr markings disappear. The dorsal fin also shows 

 an increased number of black spots, and in this fin 

 — but more commonly in the ventral and anal fins 

 alone — the anterior margin sometimes becomes red or 

 white, which colour is usually marked off sharply be- 

 hind, as in the Charrs, by a black streak. The young 

 Trout which are to repair to the sea or the great lakes 



assume, like the Salmon Parrs, a ligliter, more and 

 more sihery dress. 



In salt water, as well as in the great lakes, the 

 main alteration in the colouring of the Salmons after 

 the Forell (Smolt) stage affects the black spots, which 

 pass from a round or irregularly angular shape to a 

 stellate form (X-spots). As a rule, however, though 

 by no means always, the two varieties may be distin- 

 guished even in the sea by their coloration, the Sea 

 Trout being usually more thickly spotted than the true 

 Salmon, and bearing numerous black spots even below 

 the lateral line and on the greater part of the Ijody, 

 even behind. Such is the case with the Tabncn from 

 Tornea figured by v. Wright (Plate XXXVIII, fig. 3). 

 Under certain conditions, however, especially in the 

 sterile individuals mentioned above and in the speci- 

 mens which should probably be explained as hybrids 

 (mongrels), this difference vanishes. Nor is there any 

 constant distinction in colouring between the marine 

 form kno\vn in England as the Sewin {Salmo camhri- 

 cus) and a true Salmon. How this distinction asserts 

 itself in Scandinavian waters, may be gathered from 

 a comparison between v. Wright's figures of a Salmon 

 (Plate XXXVm, fig. 1) and a Silver Salmon (Plate 

 XXXVIII, fig. 2). 



The Salmon ^vhich have no access to the sea or 

 to any large, deep, and clear lake — whose Oriiig and 

 Lax stages are thus moi-e immediate progressions from 

 the Forell stage — are remarkable for the exceeding 

 inconstancy of their colours, whence Lunel proposed 

 to unite them under a distinct specific name, Tniita 

 raruiltilis. In Scandinavia, as elsewhere, they occur in 

 brooks, rivers, and lakes. They are usually' small, '/j 

 — 1 lb. in weight, but frequently weigh 10 lbs., some- 

 times up to 18 lbs. Their coloration — lighter (redder) 

 or darker (sometimes nearly black), with denser or 

 more scattered red and black spots — is determined, 

 as in most fishes, primarily by the colour and light 

 of their surroundings, but also, in a high degree, by 

 their food. Of this as clear evidence as one could 

 desire was afforded by a visit in 1883 to Sir James 

 Maitlanu's hatcheries at Howietown (near Stirling). 

 Two of the ponds contained, among other fishes, a 

 variety of Trout from Loch Leven (Salmo lerenensis). 

 In one pond, where they were fed on horseflesh, the 



" See TAe Field for the 25th of April, 1863. 



' Red spots above the lateral line are not uncommon in young 



