56 OYSTEK BOTTOMS OF MISSISSIPPI SOUND, ALA. 



Oysters in the natural beds, especially when they are much clus- 

 tered and of the sharp-edged raccoon type, are rarely injured seri- 

 ously, as the sharp edges of the shells, presented in all directions, 

 lacerate the lips and mouths of the fish and deter them from extensive 

 destruction. Occasionally the small oysters cuUod off by the oyster- 

 men are damaged. 



The drumiish occurs in waters of all degrees of salinity, from fresh 

 or practically fresh to full oceanic density. 



SPAWNING. 



The survey was conducted at the season when the reproductive 

 fimctions of oysters are in abeyance, and therefore no definite state- 

 ment of the spawning season in Alabama can be made. Various 

 investigations carried on by the Bureau r.t the western end of 

 Mississippi Sound, where the general conditions affecting spawning 

 are essentially the same as at the eastern end, make it possible to 

 indicate with some precision the period during which the spawn is 

 likely to be emitted. 



It is probable that the eggs may ripen even in the winter, during 

 sustained warm periods, buo it is doubtful if in these cases, even 

 though the eggs be fertilized, development ever proceeds far enough 

 to secure a set of spat. The normal spawning probably occurs from 

 April to October, as it does in similar waters in Louisiana, and clean 

 shells or other cultch planted during those months should receive a 

 good set of spat. The young oysters are free-swimming organisms 

 during a short period of their early life, and as thoy arc produced in 

 untold myriads on the crowded natural beds and carried considerable 

 distances by the currents, the water over a large part of the sound 

 must be teeming with the fry during the favorable part of the year. 

 Most of these embryo oysters perish through falling on unsuitable 

 bottom at the beginning of the shell formation, when they are still 

 barely visible to the unaided eye and may be stifled by an exceedingly 

 thin deposit of mud or slime. Those fortunate enough to ahght on 

 shells or other oysters, and similar firm supports, survive in large 

 numbers, as is witnessed by the crowded condition of the beds, but 

 over the vastly greater proportion of the bottom there is nothing to 

 afford a haven. The only fundamental difference between an oyster 

 bed and the surrounding barren bottom is that the former presents 

 places for the attachment of the spat and the latter does not. 



Many free-swimming oyster fry die as the result of sudden drops in 

 the temperature, though this is not common on the Gulf coast; and 

 many are killed by heavy rainfalls. The latter also tend to retard or 

 suspend spawning through lowering the salinity of the water, and it 

 frequently happens that heavy freshets defer spawning until summer. 

 As freshets usually leave the shells and other cultch in excellent con- 



