Neurophysiology 
The preliminary results from neurophysiological experiments on the 
lobster’s olfactory chemoreceptors are presented with a few examples in Figure 
10-1. Details are provided in the figure legend. These examples show that (1) 
the water-accommodated fraction of #2 fuel oil itself can be perceived as a 
stimulus by the primary receptor cells, (2) that the presence of oil in a mussel 
juice food stimulus can change the response pattern of the small nerve bundle, 
and (3) that exposure to oil causes abnormal bursting patterns (See Figure 
10-4). 
Generally, differences in chemoreceptor responses between mussel and 
mussel-plus-oil are more distinct in oil-exposed lobsters than in controls. One 
other striking feature is the tendency of oil-exposed individuals to exhibit 
irregular bursts, or frequent small clusters, of spikes, both spontaneously and in 
response to stimuli (Figure 10-4), This may be a general injury response (6) 
here caused by oil exposure. However, it has also appeared in nerves from 
animals which were exposed to very low levels of oil (0.3 ppm) in response to 
mussel-plus-oil stimuli, but not to mussel alone. 
DISCUSSION 
Our experiments have shown thus far that the original hypothesis that oil 
pollution may interfere in a number of different ways with chemoreception, 
and hence marine animal behavior, is not unreasonable. Behavioral experiments 
on the efficiency of the lobster’s chemically mediated feeding behavior have 
shown that exposure to #2 fuel oil (WAF) causes significant delays after five 
days at exposure levels as low as 0.08 and 0.15 ppm. Increased dosage caused 
increasingly severe effects. Also behavioral recovery was a function of exposure 
level. At higher exposures (1.5 ppm) serious neuromuscular abnormalities 
appeared within 30 hours. Lobsters showed great individual differences in 
behavioral effects and recovery. The range of exposure levels where behavior 
was affected, but no serious neuromuscular defects appeared, proved to be 
surprisingly narrow. However, further experiments are required for complete 
documentation of this point. 
Parallel neurophysiological experiments on the effects of such exposures on 
chemoreceptor performance showed that the receptors perceive oil as a 
chemical stimulus, that the presence of oil could modify normal responses, and 
that oil-exposed lobsters ofen showed abnormal receptor activity, both 
spontaneously and in response to food stimuli. 
Based on these results, it appears that #2 fuel oil (WAF) interferes with 
lobster behavior in a number of ways. At low exposure levels (0.1 ppm range), 
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