64 OYSTER BOTTOMS IN MATAGORDA BAY. 



fish is found in water of almost any density, and no locality acces- 

 sible from the sea may b^ expected to be free from it. Often within 

 a single night, for this destroyer works chiefly in the dark, hundreds 

 of bushels of stock are ground to fragments. The fish frequently 

 congregate in considerable schools, and from 100 to 200 are known 

 to have been killed by the simultaneous explosion of two charges 

 of dynamite 50 feet apart. As the fish are large and powerful 

 the damage wrought by a school so numerous as this would indicate 

 can be readily appreciated. In the case of one grower near Tuck- 

 erton, ft. J., about 80 per cent of a total planting of 15,000 to 20,000 

 bushels is estimated to have been destroyed in a few weeks, and such 

 is the concealment which the nocturnal feeding habits of the fish 

 afford that the damage was almost completed before the owner was 

 thoroughly aware of what was occurring. The drum was, more- 

 over, a comparatively new enemy in the vicinity, and even after the 

 loss was noticed it was for some time attributed to theft. 



This fish differs from most other animals preying upon the oyster 

 in the fact that it is in general more destructive upon the planted 

 than upon the natural beds, and the better the shape of the oyster 

 the more liable it is to attack. The drum feeds upon its prey by 

 grinding it up, shell and flesh, by means of the great molar teeth 

 which floor and roof its mouth. The ill-shaped, densely clustered. 

 sharp-edged raccoon oysters, the extreme of their type, are usually 

 in such large clusters and present so many knife-like points and edges 

 that it is difficult for the drum to crush them without itself suffering 

 serious injury, and it is no uncommon thing to find the fish in the 

 vicinity of raccoon oyster beds with badly lacerated lips and mouth. 

 The planted oysters, however, especially those of the better grade, are 

 in smaller clusters, and their rounded shells can be seized by the fish 

 with much greater impunity. On the Louisiana coast, and presuma- 

 bly in Texas, unculled oysters can be bedded with comparative safety, 

 but when the clusters are" broken up in order to permit the liberated 

 individuals to grow and improve untrammeled by their fellows it is 

 necessary to surround them with stockades or netting to prevent their 

 complete destruction by the drums. As might be supposed also the 

 younger and thinner-shelled oysters are more likely to be damaged 

 than large heavy-shelled ones, and it is generally observed that the 

 period of a few weeks following planting is that of greatest danger. 

 Whether the oysters in time become more or less concealed and incon- 

 spicuous through the deposit of silt, or from some other reason, it is 

 generally observed that the old bedded stock is liable to escape while 

 adjacent recently bedded oysters are destroyed. 



In the winter the drumfish is less active and less abundant in 

 shoal water, and for this reason the survey party had little oppor- 

 tunity to study it in Matagorda Bay. During some of the extreme 



