THE SEA FISHERIES OF EASTERN NORTH AMERICA. 75 
Except in the earlier stages of life, as already explained, the chief 
sustenance of fishes in the sea consists of animal matter, either dead or 
living. While some kinds of fish are believed never to feed upon any- 
thing but living animals, others are, to a very great extent, scavengers, 
being especially appointed to devour dead or decaying substances, such 
‘as offal or the so-called gurry, &c. The cyprinodonts of the coast are 
particularly active inthisdirection. Sharks also exercise the same func- 
tion in a very marked degree. There are probably but few of the bot- 
tom fish that will disdain such substances, consuming living forms with 
the’same readiness. In the business of clearing out refuse fish they are 
assisted largely by crustaceans, certain mollusks, echini, &e. 
The living food of fishes may be divided into two sections: first, eggs 
and embryos; second, fishes and marine invertebrates of more mature 
and advanced ages. 
The earliest form in which the fish serves as food for its fellows in the 
sea is in that of the egg, and it is for this reason that with the enormous 
fecundity of certain fish there is so little apparent increase in their 
schools. It may safely be assumed that only a small fraction of 1 per 
cent. of the total number of eggs laid by fishes ever develop embryo 
fish, by far the greater part being devoured in a very short time. The 
young fish, also, after birth, is for a certain time immature and to acon- 
siderable degree helpless and only able to take food for itself after the 
absorption of its yolk-bag and the accompanying development of its 
fins. before it assumes the shape of the perfect fish and is able to care 
for itself, it becomes a prey to innumerable enemies; and if of the orig- 
inal deposit of eggs one fish becomes able to care for itself by feeding 
and hiding to every ten thousand eggs hatched, it may be considered a 
very satisfactory yield. The proportion, however, doubtless varies with 
the species. 
Under the rate of the fecundity of fishes will be found a table of the 
numbers of eggs laid by particular kinds of fishes, partly copied from 
Buckland and partly original, from which we understand that even 
with this percentage of loss there is still a margin left for the main- 
tenance of the species. 
Althongh the percentage of loss after the embryonic development of 
the fish is complete is less than before, there is still a very great drain 
upon the numbers of the species, there being at every step an enemy 
Jurking in wait to devour. 
_ To the large fishes of course there comes a time of comparative 
immunity, when nothing but the rarer and more powerful inhabitants 
et the sea can interfere. Even then, however, numbers of smaller ene- 
‘mmies may combine together for the overthrow of the monsters that 
would be more than a match singly for any antagonist, and thus while 
fish of the known voracity of the cod, haddock, &ec., may consume 
readily species of a smaller size, they have as their antagonists the 
sharks, the various porpoises, and other cetaceans, and the rarer 










