this study, using the water-accommodated fraction (WAF) of #2 fuel oil, we 

 are mainly concerned with distance chemoreception of the antennules. 



The first purpose of these experiments is to determine the range of #2 fuel 

 oil exposures that affect the feeding behavior of lobsters without causing 

 neuromuscular disturbance. Since chemoreception provides an important inpui 

 into their feeding behavior, we then apply neurophysiological techniques to 

 measure the effects of oil exposure on chemo receptors in animals, where 

 sublethal behavioral abnormalities have been shown. This is the second goal of 

 these experiments. The results reported here are preliminary; the methods 

 are established. 



MATERIALS AND METHODS 



Flow-Through Oil Dosing System 



In order to measure actual exposure levels, a continuous flow-through oil 

 dosing system is necessary. The flow-through system (Figure 10-1) consisted of 

 two head tanks, one control and one experimental. The experimental head 

 tank, 8' X 11" x 8", was fitted with three baffles to aid in the layering of the 

 oil after mixing. Its inflow was 4,000 ml/min. Oil was introduced via a syringe 

 pump at a fixed rate into the center of the fast jet of seawater, causing rapid 

 emulsification. The overflow of the head tank was skimmed off into a 

 collecting tank where the oil layer was siphoned off occasionally. From the 

 head tank, the oil-water mixture entered six 100-liter tanks individually. 



The overflow from the individual tanks entered a holding tank where 

 lobsters were stored for neurophysiological preparations on oil-exposed 

 animals. The overflow from the collecting box and the holding tank entered an 

 acrylic-fiber filter box, where oil was removed before the water entered the 

 drain (Figure 10-1). The control head tank, 4' x 11" x 8", supplied four 

 individual 100-liter tanks. Its inflow was 2,600 ml/min. Individual tanks, both 

 experimental and control, had inflows ranging from 400-460 ml/min. Water 

 quality — salinity, temperature, ammonia, pH and O^ content — and flow rate 

 to individual tanks were measured every other day. 



Behavior 



Two male and two female lobsters served as controls, three males and three 

 females as experimental. From our holding faciUty, we chose lobsters which 

 had molted within two to eight weeks of the start of the experiment, to avoid 

 effects of pre-molt behavior during observation. The animals were measured for 

 close size match, and put in individual tanks containing a glazed clay shelter 

 and a pebble substrate. They were fed twice daily until all animals were feeding 

 normally. Then a base line for feeding behavior was determined over a five-day 

 period. During the whole experiment lobsters were observed daily in the early 

 morning (7-9 am) and late afternoon (4-6 pm). One-minute behavior recordings 

 were followed by the addition of food, which was lowered on a string from the 

 right or left front corners, alternately. Apart from general behavior (about 25 



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