THE CHEMICAL SENSE AND FEEDING BEHAVIOR 

 OF NEREIS VIRENS. SARS. 



MANTON COPELAND AND H. L. WIEMAN, 

 MARINE BIOLOGICAL LABORATORY, WOODS HOLE, MASS. 



In 1873 Verrill stated in his report on the invertebrates of 

 Vineyard Sound that the clam worm, Nereis virens, " feeds on 

 other worms and various kinds of marine animals. It captures 

 its prey by suddenly thrusting out its proboscis and seizing hold 

 with the two terminal jaws; then withdrawing the proboscis, the 

 food is torn and masticated at leisure. . . . ' Maxwell (1897) 

 confirmed Verrill's conclusions as to the character of its food. 

 He found that if a small piece of worm on the end of a needle 

 is placed within reach of a normal Nereis, the animal seizes the 

 food and devours it. More recently, however, Gross (1921) has 

 failed to find any evidence that Nereis virens is a carnivorous 

 worm ; concluding that it feeds principally upon plant life. This 

 verdict was based upon studies in the laboratory and in the field. 



Our own observations began with dropping crushed peri- 

 winkles [Litorina littorea (Linn.)] in shallow water at low tide 

 in order to study the responses of crustaceans. That such bait 

 would cause Nereis to react was a thought that had not occurred 

 to us, so that our surprise can easily be imagined when presently 

 a worm extended the anterior end of its body from below smooth 

 sand, moved toward the snail, seized and quickly jerked it down 

 into its burrow. What we saw was a confirmation of Verrill's 

 statement noted above. 



Subsequent tests with the same food resulted in numerous 

 responses of a similar nature until it appeared that Nereis was 

 reacting with remarkable precision to small amounts of mate- 

 rials emanating from the crushed snails. A worm usually 

 emerged several centimeters from the snail, and advanced rather 

 slowly over the surface of the sand by movements of the body 

 and parapodia toward the bait, which it finally seized in its 

 powerful jaws and drew rapidly to its burrow by a sudden 



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