794 
SCANDINAVIAN FISHES. 
8 2 V 2 “ of that from the same point to the dorsal fin. 
The preabdominal length measures on an average 22 V 2 
%, and the postabdominal length 18V 2 %■> of the length 
of the body. 
The texture of the thin scales has already been 
remarked. It is fairly characteristic of the Bleaks and 
their nearest relatives, in the dense, concentric striae, 
most dense in the anterior (covered) part of the scale, 
around the eccentric nucleus, which also lies in the 
covered part. Towards the nucleus run a few (on the 
scales of the sides commonly 4, on the dorsal scales 
as many as 10) scattered grooves, extending forward 
for a greater or less distance from the hind margin 
of the scale. The scales are generally of a broad 
elliptical shape (those of the lateral line more quadri- 
lateral, with the posterior part rounded), the longi- 
tudinal axis of the ellipse pointing up and down. They 
are rather large, but deciduous. The inner surface of 
their posterior part is lined with a dense layer of long, 
almost filiform crystals, which give them their silvery 
lustre. 
The colour of the back and the upper part of the 
head is greenish gray. The rest of the body is silvery. 
The iris is also silvery, but above the pupil yellowish, 
with dense, confluent spots of gray. The pectoral, 
ventral, and anal fins are white, the first pair faintly 
tinged with green at the anterior margin. The dorsal 
and caudal fins are gray. 
The Bleak is spread over the whole of Europe 
north of the Alps, with the exception of Scotland and 
Ireland 6 . In Sweden it is common enough, under the 
names of Loja, Loga , Benloja, Pjon , Pyn, etc., up to 
the neighbourhood of Quickjock 0 (lat. 67° N.). It does 
not seem to thrive, however, in the highlands, for it 
is rare in Lapland, and in Western Jemtland, according 
to Olsson, it is wanting 16 . In Finland, where it is 
called SalakJca, a name which at Tornea is altered, 
says Widegren, to Salk, its range extends, according 
to Mela, to 68° 20' N. lat. In Norway, a country 
not very rich in Cyprinoids, the Bleak is found 
only in the south-east, no further north, accord- 
ing to Collett, than Lake Mjosen. It lives in the 
great lakes, in clear rivers and streams, and also in 
“ According to our measurements 79 — 82'2 /. 
the inner part of the Baltic island-belt, as well as in 
Gothland and round the coasts of that island. Accord- 
ing to Schagekstrom it also occurs in the Sound, at 
least off Landskrona. 
The Bleak lives in shoals, solitary specimens being 
never met with, and prefers clear, running water with 
a stony or sandy bottom. It is consequently found 
but seldom in small lakes with a bottom of weeds or 
mud. Sportive and lively in temperament, it always 
keeps to the surface from spring to autumn, and 
catches the insects that drop into the water. It loves 
sunshine and calm, and in rainy and stormy weather 
makes for sheltered shores. At such times it probably 
descends some way below the surface, but it does not 
stay there long, and is never found at the bottom, 
except in autumn, when, like the other Cyprinoids, it 
retires to its winter-quarters in the depths. Less shy 
than timid, it soon returns to the spot whence it has 
been driven away by some noise. On the other hand, 
it is voracious, and instantly seizes any small sub- 
stance thrown into the water. If it finds the morsel 
unfit for food, it again disgorges its prize. Its food 
consists principally of insects, small crustaceans, and 
worms. 
At the end of May or beginning of June the 
Bleak assembles in large shoals to spawn in shallow 
water with a stony or sandy bottom. The shoal presses 
in serried array close to the shore, and seems like a 
dark cloud in the water. The spawning now begins; 
the fish leap time after time, at brief intervals, above 
the surface, and meanwhile deal frequent and rapid 
blows with the tail on the water, thus producing a 
hissing sound like that heard when a piece of cloth is 
suddenly torn in two. The roe attaches itself to stones 
or twigs at the bottom. How soon the eggs are hatched 
under ordinary circumstances, we cannot state with 
certainty, the time allotted by different statements to 
this process varying between 24 hours and as many 
days; but it undoubtedly varies according to the tem- 
perature of the water. Of the growth of the fry we 
learn from Malm that in the middle of September he 
caught young Bleak 18 — 23 mm. long in the Hoje 
(a stream in Scania); and in Lake Millar Lilljeborg 
411. The statement is, however, somewhat dubious, for the spawning- 
b Day, 1. c. 
c According to LSwenhjelm, Vet. : Akad. Handl. 1843, p. 
season is said to occur in September. 
d According to Fatio it ascends in the Swiss lakes to a height of about 700 m. above the level of the sea. 
