Translation Series No.1211

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vertical movements also in winter. The share of these kinds of fish . there-
fore changes often in the opposite direction from that of the sprat.
Belone and sand eel become more conspicuous only when the clupeids.beoote
scarcer.
6.5. The food consumption of the salmon
For the treatment of this question we have only the mean weight
of food, which was, according to Table 49, at its lowest during the six
months October . to March. For this period we obtain as the simple mean a
value of 8.7 g stomach content. The corresponding amount for the remaining «
four months amounts to 39.3 g. If we assume that the latter value applies
also to the months July and August, for which there is no informatiOn, •
then the annual mean for the weight of food is 24 g.
In the literature available to me (W. O. Côrnelius 1933, H. Mann
1955, M. E. Brown 1957, various authors after E. J. W. Barrington 1957)
are few statements about . the'frequency of food intake in fish and none for
the salmon.-
According to. Barrington (1957) the speed of digestion is smaller
in fish than in memals on account of the lower temperature. At 10 ° C the
.food passes through the - carp in 181Tr, at 26 ° C it does so in 4.5 hr. In
sharks the digestion is supposed to be complete after three days. Karpevich
and Bokova (after Suvorov 1959) state for cod and sea scorpion that the
skin.of fOod fish.that is in contact with the walls of the stomach is in
part dissolved after 5 hr. Cornelius (1933) fed-fingerlings of the , rainbow
trout.With trout fry. He found the first indications of digestion on skin
and fins of 'the fOod . fish. After five hours fins, skin and eyes were decom-
•posed and the body.càvity had.been opened. The body shape was no longer