44 
IL— FOOD OF FISH CAUGHT AT THE TRAWLING 
EXPERIMENTS. 
The observations on the food, etc., of the fishes, made in 1905, 
are given in Table XII. 
A similar record has been kept each year since 1896, and the 
results for the whole period are presented in table XIII. In the 
latter table it will be seen that in certain cases the occurrence of the 
food is expressed by ' * '. This is because the records for 1897, and 
for several other years were destroyed by the fire at the laboratory, 
and I have had to be content with the reports which have been 
printed. 
Although the diet of the fish in the inshore waters of Northum- 
berland is variable in its nature, the results, as a whole, show that 
that of plaice is essentially a molluscan one ; that of the dab and 
of the thornback, crustacean ; and that of soles, turbot, and brill, 
fish. The flounder is not so constant, but confines its attention 
mainly to fish and mollusca ; and gurnards similarly to fish and 
crustaceans. 
The mollusca which are most frequently used are Donax truncitlus 
and Tellina tenuis, and the common crustacean is Portunus hohatus. 
The percentage occurrence of these and sandeels in all tbe fish 
examined is given in the following table : — 
1896 
1898 
1899 
1900 
1901 
1902 
1903 
1901 
1905 
Sandeel 
. 20 
33 
19 
5 
10 
37 
27 
56 
9 
Donax truneulua 
. 4G 
3 
3 
4 
2 
1 
7 
2 
2 
Tellina tenuis 
. 14 
11 
14 
8 
11 
13 
7 
4 
5 
Portunus holsatus 
. 32 
10 
8 
4 
18 
14 
12 
8 
6 
Empty . 
. 58 
34 
23 
30 
42 
80 
63 
47 
53 
It is interesting to note that in the later years, in 1904 especially 
sandeels had taken an important place in the diet of the fish. It is 
a fact, moreover, that during these latter years Portunus holsatui 
which forms the chief food of the dab, and contributes largely to 
that of the thornback and the gurnard, has not been so conspicuous 
in the trawl. The same could be said to be true of Donax trunculus 
which with Tellina tenuis was the principal food of plaice at the 
beginning of the decade. It is obvious that the common forms of 
