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EFFECT OF NO. 2 FUEL OIL ON 

 LOBSTER FEEDING BEHAVIOR 



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36 48 60 

 POST 



72 84 96 108 120 132 144 (HRS.) 



Figure 10-3. Effect of 1.5 ppm No. 2 Fuel Oil (WAF) 

 on Lobster Feeding Behavior. 



NOTE: Large bars indicate number of lobsters not feeding within 10 minutes 

 of food introduction. Broken line represents estimated oil levels in lobster 

 tanks based on actual recovery measurements (indicated by dots and stand- 

 ard deviation bars). Hatched horizontal bar shows period of oil introduction 

 into the system. "Pre" is the 5 day pre-exposure period: all lobsters feed and 

 recovered oil remains below 0.05 ppm. "Oil" is the exposure period: highest 

 mean exposure level 1 .7 ppm, oil stopped after 30 hrs. "Post" is the recovery 

 period: oil quickly leaves the system, feeding behavior remains seriously af- 

 fected for the entire 5-day period. 



• Moderate (three lobsters) - These animals were generally out of their 

 burrows in two alternating stances. In one, tlie tail and head were down, 

 the antennae were folded back, the antennules beat slowly, and the 

 animal lay down low on the walking legs. This appeared to be a resting 

 position. Then the tail and head arched up, the claws were opened and 

 held close to the body, the antennae and antennules were held straight up 

 and together, animal stood high on walking legs, and made frequent tail 

 flips. Poor coordination was exhibited. Frequent aggressive lunges were 

 made with open, raised seizer claw, or jabs with both claws at no obvious 

 target. Lobsters were unaware of the presence of food, at times walking 

 right over it without responding. If they did pick up the food, they 

 continued to wander aimlessly around the tank with the food clutched 

 tightly in the maxiUipeds. Recovery in five days was almost complete in 

 two animals; one animal did not recover. 



• Light (one lobster) — This animal remained in its burrow but was high on 

 its walking legs, "spider" position and shaking. There were sporadic alerts 

 not necessarily related to food. It exhibited no search. After two days 

 recovery, there were slow hesitant approaches to the food with tail flips at 

 the shghtest irregularity. At the end of five days there was complete 

 recovery. 



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