214 
THE BOOK OF FISHES 
Photograph from Dr. Hugh M. Smith 
ANATOMY OF THE OYSTER 
“It is an astonishing biological fact that in some species of oyster each sex is represented by a different 
individual, as in the oyster of the Atlantic coast of North America; while in other species both sexes are 
united in one individual—the male stage alternating with the female, as in the common oyster of the 
Atlantic coast of Europe.” 
where, at the present time, fully 90 per 
cent of the output represents oysters that 
have undergone some kind of culture. 
In other parts of the Old World the 
growing of oysters by artificial means 
has become an important industry, while 
in the Western Hemisphere oyster farm¬ 
ing has progressed to such a point that 
the annual crop now exceeds the total 
product of the rest of the world. 
Oysters are thus become the most ex¬ 
tensively cultivated of all aquatic ani¬ 
mals, and the yearly product of the oyster 
farms is many times more valuable than 
that of all other aquicultural operations 
combined. 
The cultivation of oysters is made 
necessary by the exhaustion of the nat¬ 
ural beds; it is made possible by private 
ownership or control of oyster-producing 
bottoms; and it is greatly facilitated by 
the peculiar susceptibility of oysters to 
increase and improvement by artificial 
means. 
THE OYSTER HAS MANY ENEMIES 
The human animal is not the only one 
that looks with favor upon the edible 
qualities of the oyster. At every stage 
in its career it is attacked by a horde of 
dangerous enemies, some of which are 
most destructive after the oyster has put 
on its stoutest armor and would seem 
to be almost invulnerable. Before it be¬ 
comes attached, the delicate oyster fry is 
extensively consumed by adult oysters 
and various other shellfish, as well as by 
fishes like the Menhaden, which are able 
to strain their food from the water. 
When the oyster attains its shell, a new 
