FISHERY BULLETIN: VOL 77, NO 3 



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5 nm 



Figure 2— The ultrastructurc of the dorsal parapodial cirrus of thepolychaete f/iyWorfoce mucosa. The micrograph shows the dense 

 array of cilia and microvilli which line the cirral epithelium as well as mature and immature secretory droplets and associated 

 organelles. Anderson's and osmium tetroxide fixation, uranyl acetate, and Sato lead stain. S = mature secretory droplets; A = 

 mitochondria; E = smooth endoplasmic reticulum. Other abbreviations as in Figure 1 



species of phyllodocids in the food of the haddock, 

 Melanogrammus aeglefinis. No phyllodocids were 

 among the 11 dominant prey species of the larger 

 fish examined. VVigley noted, however, that be- 

 cause of the small, subterminal mouth, most of the 

 haddocks' prey were small and thin. Small inver- 

 tebrates, including phyllodocids, were listed as 

 dominant foods of the few smaller 1 14-.30 cm) had- 

 dock examined. Annelids composed only 1.9'/i of 

 the prey items found in the haddock study and no 

 note was made of the diet offish •14 cm. Data for 

 small juveniles is found in only a few studies in- 

 volving bulk analysis of fish stomach contents 

 iStickney et al. 1975; Chao and Musick 1977). 



In nature, initial rejection and adverse reaction 

 of a fish to P. mucosa may give the potential prey 



sufficient time to retreat from harm. Chiszar and 

 Windell (1973) found that satiated bluegill, 

 Lepomis inacrochirus, have more selective feeding 

 habits than starved fish. This may imply that in 

 natural conditions a normally feeding fish may not 

 persist in an attack on an unpalatable prey or- 

 ganism. 



Murdoch et al. ( 1975) suggested that predators 

 distribute attacks among prey species in response 

 to the prey's relative densities. These authors 

 broke down events leading to final ingestion of 

 prey into a series of predatory behaviors, includ- 

 ing "choosing" to attack the prey species. Once a 

 potential prey is perceived and located, the 

 "choice" is up to the predator whether to attack or 

 not. If the organism is attacked and successfully 



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