120 MARVELS OF FISH LIFE 
pilchard, the shad and the anchovy. These fish swim in 
shoals, and are usually to be found in mid-water or near 
the surface at no great distance from our coast. Her- 
rings feed entirely upon crustaceans, which swarm in 
the sea, and they strain this food from the water by 
means of a sieve-hke arrangement in the throat. When 
considering the throat teeth of the carp, I referred to 
the bony bars on each side to which are attached the 
gill filaments. In the herring, on the first pair of bars 
are rows of stiff poimted projections like the teeth of a 
comb. These projections are known as gill-rakers. It 
is by means of these gill-rakers that the food of the 
herring family is strained from the sea. 
The herring and the sprat often frequent brackish 
water, and as already stated, herring frequently spawn 
in water sufficiently fresh to permit of their eggs being 
attached to the leaves of fresh-water plants. The shad 
ascends into fresh water to spawn, but the pilchard and 
anchovy keep entirely to the sea. 
In the herring family we have examples of the three 
types of eggs found among bony fishes. The eggs of the 
shad are heavy, but free from each other, and lie on the 
bottom like the eggs of the salmon. Herring eggs are 
heavy and adhesive and are attached to stones and 
gravel, while those of the sprat, pilchard and anchovy 
float like those of the plaice and cod. 
Herring spawn is deposited during the summer and 
again in the winter, but the same fish does not spawn 
twice in one year. for it is now known that summer- 
