488 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



figure of 300 bushels per acre per annum. A 

 bushel of Gulf oysters will yield 4 pounds of 

 completely drained meat. When we assume that 

 at least 1 ,400 square miles of Gulf oyster bottoms 

 could be put into production, we find that on a 

 sustained yield basis the industry could produce 

 in excess of 500,000 tons of oyster-meat each 

 year. The entire production of the United States 

 now approximates less than 10 percent of this 

 figure. 



There are at least three other species of oysters 

 in the Gulf, all members of the genus Ostrea 

 (Gunter 1951b). 0. equestris is a small species 

 occurring discontinuously from Texas to Florida. 

 0. frons has been reported most frequently from 

 southern Florida, but it exists at Pensacola and 

 has been found off the Texas coast. These two 

 are quite similar; they exist at salinity levels 

 usually above 25 parts per thousand and are most 

 commonly found at the junction of Gulf and bay 

 waters. Their setting periods coincide with the 

 spatfall of C. virginica. In areas where one of 

 these species occurs with C. virginica they may 

 be confused because of their superficial similarity 

 when about an inch in diameter. Large numbers 

 of 0. equestris were actually transplanted in 

 Apalachicola Bay at one time on the mistaken 

 assumption that they were seed of the commercial 

 oyster. In the fall months C. virginica spat 

 quickly surpass the spat of Ostrea in length. At 

 the age of 1 year, 0. jrons and equestris still 

 approximate one inch in both length and width, 

 although rarely they attain a length of 2}^ inches 

 in an unusually favorable environment. In- 

 ternally, both 0. frons and equestris are dis- 

 tinguished from C. virginica by a variable number 

 of denticles on the anterior edges of the valves 

 and by the absence of pigment in the muscle 

 attachment area. These oysters are larviparous, 

 and during the summer months the mantle cavity 

 frequently contains large numbers of offspring in 

 a manner similar to the European oyster, 0. 

 edulis. Spat of the three oysters, 0. frons, 0. 

 equestris, and C. virginica were found in abundance 

 on the same cultch at Pensacola during the 

 summers of 1949 and 1950. This mutual occur- 

 rence of the three species in time and space is 

 probablj'^ infrequent. A third species, 0. per- 

 mollis, the sponge oyster, is rather common on the 



Florida coast in shallow water. It is a small, 

 flat oj'ster, up to 2 inches in length, yellow brown 

 in color and most frequently found living inside 

 of masses of the bread sponge. 



The ecology of the oyster in the Gulf of Mexico 

 parallels, in many respects, conditions found along 

 the Atlantic seaboard. Where significant bio- 

 logical differences exist between the two areas, 

 they are due primarily to the higher temperature 

 levels of the Gulf environment. The biological 

 and economic problems facing the industry here 

 have their counterpart in other oyster producing 

 areas. The industry in the South can include 

 among its distinctive advantages an unlimited area 

 for the expansion of cultivated grounds and a 

 seemingly inexhaustible supply of seed oysters. 



LITERATURE CITED 



Butler, Philip A. 



1 95 1 . Erosion and the littoral benthos. Shore and Beach 

 19 (1): 7-11, April. 

 Engle, James B. 



1948. Investigations of the oyster reefs of Mississippi, 

 Louisiana, and Alabama following the hurricane of 

 September 19, 1947. U. S. Dept. Int., Fish and 

 Wildlife Service, Spec. Sci. Rept. No. 59. 



Gunter, Gordon. 



1951a. The West Indian tree oyster on the Louisiana 

 coast, and notes on growth of the three Gulf coast 

 oysters. Science 113 (2940): 516-517. 

 1951b. The species of oysters of the Gulf, Caribbean 

 and West Indian regions. Bull. Mar. Sci. Gulf and 

 Caribbean 1 (1) : 40-45. 

 Ingle, Robert M. 



1951. Spawning and setting of oysters in relation to 

 seasonal environmental changes. Bull. Mar. Sci. 

 Gulf and Caribbean 1 (2): 111-135. 

 Landau, Helen, and Galtsoff, Paul S. 



1951. Distribution of Nematopsis infection of the 

 oyster grounds of the Chesapeake Bay and in other 

 waters of the Atlantic and Gulf States. Texas Jour. 

 Sci. 3 (1): 115-130. 

 Loosanoff, v. L., and Engle, James B. 



1940. Spawning and setting of oysters in Long Island 

 Sound in 1937, and discussion of the method for pre- 

 dicting the intensity and time of oyster setting. 

 Bull. U. S. Bur. Fish., 1950, 49: 217-255. 

 and NoMEJKO, C. A. 



1949. Growth of oysters, 0. virginica, during different 

 months. Biol. Bull. 97 (1): 82-94. 



Mackin, John G. 



1946. A study of oyster strike on the seaside of Virginia. 

 Virginia Fish. Lab., College of William and Mary, 

 Contr. No. 25, pp. 1-18. 



