CXXVIII REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



The diatom Navicula ostrearia, which produces the green pigment 

 investigated by Lankester and others, was not found in the Lynnhaven 

 oysters, and the stomach contents presented the same golden-brown 

 coloration commonly found in normal oysters. It is evident that this 

 greenness is quite different from that investigated by Boyce and Herd- 

 man,* and before them by Ryder. The green color was confined to the 

 gills and palps, and no pigment whatever was found in the heart, peri- 

 cardium, or blood cells. Practical tests have shown that these oysters 

 may be safely eaten in large quantities. 



RED OR "BLOODY" OYSTERS. 



During the oyster season of 1896-97, the oysters on certain parts of 

 the Virginia coast were affected with a peculiar condition which has 

 heretofore been very rarely observed in this section. In making a 

 canvass of the oyster industry of the State in the spring of 1898, Mr. 

 W. A. Wilcox, agent of the Fish Commission, secured the following 

 information regarding the extent and appearance of the affection: It 

 seems to have been first noticed in the season of 1895-96, when a few 

 oysters from the upper oyster-grounds in the Rappahannock River were 

 found to have a reddish color, and received the local name of " bloody 

 oysters." At the outset the grounds involved were not extensive, but 

 by the next season most of the beds down the river were affected, as 

 well as numerous adjacent smaller- water courses in Lancaster and Mid- 

 dlesex counties and a limited area in Chesapeake Bay off the mouth of 

 the river. 



It is reported that there were "-bloody" oysters also on the shores 

 of Chesapeake Bay north of the mouth of the Potomac. Information 

 has been received indicating the occurrence of a similar condition in 

 parts of Chesapeake Bay about ten years ago. 



When these oysters were examined in October, 1896, the red discol- 

 oration involved only the region of the gills, but a little later it extended 

 throughout the oyster and its liquor. During the early spring of 1897 

 the color gradually disappeared ; by the close of the season few, if any, 

 red oysters were to be found, and none has since been reported. 



The existence of red oysters in the Rappahannock region resulted in 

 a serious disturbance of the oyster fishery and trade. The greatest 

 pecuniary loss was due to the prejudice which arose against the oysters 

 from the affected districts, the fear being generally entertained that 

 those which seemed normal when first gathered might develop the red 

 color before reaching the consumer. In some instances cargoes of 

 oysters that on close inspection were entirely normal would, on arriving 

 at Norfolk or other markets, show the reddish color, which gradually 

 involved the entire cargo, necessitating the return and replanting or 

 the throwing away of the oysters. 



In conversation with Norfolk oyster-dealers, the writer was informed 



*On a green leucocytosiss in oysters, associated with the presence of copper in the 

 leucocytes. — Proceedings of the Royal Society, vol. 62. 



