66 OYSTER BOTTOMS IN VICINITY OF APALACHICOLA, FLA. 
the inner cavity was seldom penetrated. At a few stations a coral 
growth was observed on the oysters. Marine alge were noted grow- 
ing luxuriantly on the clusters at a number of stations, usually near 
the inner limits of the beds. 
SPAWNING. 
The conditions of spawning probably do not differ from those 
generally obtainmmg on the Gulf coast, and it is therefore not nec- 
essary to discuss the subject at any length. It will suffice to repeat 
what has been said in a previous report.@ 
The spawning of oysters consists, in brief, of the discharge of eggs 
from the female and spermatozoa from the male which meet and fuse 
in the surrounding water. The fertilized eggs develop into minute 
embryos, each furnished with a little brush of cilia or hairlike proc- 
esses which vibrate in rhythm and propel it feebly through the water. 
After a time, varying with the temperature of the water, the embryos 
develop a tiny shell, which by its weight eventually precipitates 
them to the bottom, where, if they fall upon a suitable, clean, firm, 
support, they attach and grow into spat, but if not they speedily die. 
As their own powers of locomotion are inconsiderable, the wide dis- 
tribution of the young oysters in their swimming stage is dependent 
upon the currents. ¥ 
Oysters in the spawning condition are of a peculiar creamy color, 
with branching lines traced over the surfaces of the body. When 
they are cut the ripe genital products at once exude from the wound, 
but if the shell be opened carefully and a gentle pressure exerted 
upon the body they will be discharged from a definite opening lymg 
below the muscle (usually called by the oystermen the ‘‘eye”’ or 
‘‘heart””) which extends between the two valves. This is the pore 
from which they flow in the normal process. Ripe oysters in the 
language of the oystermen are aptly described as ‘‘milky.” 
Spawning takes place, in the main, during spring and summer, in 
any given region, extending over a period of some months, depending 
upon the latitude and the climate. On the Gulf coast I have found 
during almost every month oysters which were apparently ripe, and 
from which there were obtained eggs which readily separated in the 
water and had every appearance of maturity. Whether such eggs — 
would be extruded during the winter under natural conditions is 
doubtful, and if they were it is practically certain that they would 
not develop, as the experience of all investigators has shown that 
development is inhibited if the temperature of the water drops ma- 
terially below 70°. 
The oysters were first observed in ‘‘milk” in Apalachicola Bay on 
March 15, but owing to a decided fall in temperature the development 
@ Moore, H.F.: Oyster bottoms in Matagorda Bay. Bureau of Fisheries document no. 610, 1905. 
