EFFECT OF ORGANIC SUBSTANCES ON OYSTERS 



179 



ANOMALOUS RESPONSES 



The carbohydrate-temperature relation is not 

 the only factor to which oysters respond. Others 

 are involved, and they must often dominate the 

 oyster's behavior pattern, and conceal the effects 

 of the carbohydrates. As previously stated, it 

 must be recognized that we do not know that the 

 substances indicated as carbohydrates by the test 

 are always true carbohydrates. Further, we can- 

 not say which of the many carbohydrates are 

 responding to the test, nor can we say which of 

 the carbohydrates are represented. There is the 

 possibility that the oyster is responding to a single 

 carbohydrate which varies considerably, but whose 

 variation may be completely hidden by other 

 carbohydrates which may be far more abundant 

 at times. Bell (1948) states that "numerous so- 



called glycogens in plants and animals may not 

 be chemically identical with animal glycogens, 

 which may quite well vary among themselves." 

 Since glycogen is one of the carbohydrates, the 

 significance is apparent. 



Figure 12 demonstrates an extreme of variation 

 between oysters in their responses to variations 

 in carbohydrate concentrations. Note that oyster 

 88 was comparatively insensitive to carbohydrate 

 changes during the first few days, especially on 

 December 7. By comparison, oyster 87 was 

 markedly responsive to the material throughout. 

 Despite the anomalies (which may be due to the 

 sampling difficulties previously pointed out), these 

 figures illustrate the influence of consistently low 

 carbohydrate levels, particularly during the winter 

 period. 



