28 



After the attaehinent of the spat, other enemies, both active 

 and passive, wage a never ceasing warfare on the oyster; so 

 that the number of eggs that give rise to adult oysters Avill be 

 enly a small proportion of the whole number fertilized. 



The oyster beds of the Louisiana coast are particularly for- 

 tunate in their freedom from some of the worst enemies of the 

 oyster that occur in the more Northern waters-. The starfisk 

 by far the most destructive enemy, is, so far as any records and 

 observations show, entirely absent from the oyster beds of this 

 coast; although some of the small starfish are frequently taken 

 in the gulf in water from two to four fathoms deep. This form, 

 however, is not the same as the one that does the damage on 

 the Northern beds, and in a great many specimens examined, 

 the only food found in the stomach consisted of one of the srr..,.!! 

 clam-like molluscs that is very abundant in the shallow waters 

 of the Gulf. 



The oyster drill {TJrosalpinx cinerea) is also absent from 

 the oyster-producing regions of tliis State. 



Several of the large marine snails, or conchs, are found 

 quite abundantly along the coast; but so far as can be learned 

 they do no appreciable amount of damage to the oyster beds. 



A boring sponge (Cliona sulphurea) is present in some 

 sections of the oyster fields; but it has not been found in the 

 later stage of its development except in a very few instances. 

 In the younger stages this fonu bores into the outer layers of 

 the shells of living oysters, as well as in any empty shell, forming 

 intricate systems of burrows from the openings of which the 

 orange-colored sponge protrudes in little finger-like processes 

 one-eighth to one-half an inch long. In this stage the sponge 

 has been found on the oyster beds, both natural and artificial, 

 in many parts of the State. 



In the later stages of its development the sponge grows up 

 into a larffe mass which covers the outer surface of the shell or 

 oyster, and on this account makes it impossible for the latter to 

 procure food and oxygen, so that at last it finally dies or be- 

 comes so emaciated that it is of no value for the market. 



In the younger stages the burrows are of no particular harm 

 except that they tend to weaken tlie shell, and may also detract 

 from the appearance of the oysters when they are to be sold as 



