S^?-^ 



The cockles bore holes through the mussel shell, and 

 then, inserting the proboscis, eat the mussel alive. 

 (Cockle at left, Lunalia heros; Cockle at right, Neverila 

 duplicaia) 



a mussel you will often discover a little 

 crab, Pinnutheres maciilatum, which is a 

 first cousin to the little crab sometimes 

 found in the dish of oyster stew. It has 

 been asserted that this little fellow hides 

 here to escape his enemies and when the 

 current happens to bring morsels of 

 food close to the hiding place the crab 

 rushes out, seizes and carries them in, 

 where he tears them to pieces and shares 

 the meal with the mussel in return for 

 the protection received. The tale is in- 

 teresting but lacks confirmation. 



Aside from these friendly dwellers in 

 the mussel community there are numer- 

 ous predacious species that pay unwel- 

 come visits. Of these the starfish is the 

 archfiend of them all, for to the starfish 

 "palate" there is nothing like mussel 

 flesh and his appetite for it is never 

 satisfied. The starfish seizes the mol- 

 lusk in such a position that its mouth 



comes to lie opposite the opening of the 

 shell. Then, by attaching its numerous 

 tube feet to the opposite valves of the 

 mollusk it begins to pull gradually and 

 constantly with a force that in the case 

 of a large starfish has been shown to 

 equal two and a half pounds. The 

 starfish rests by shifting its work from 

 one set of muscles to another, wliile 

 the plucky mussel, relying on the single 

 muscle that holds the two parts of its 

 shell together, becomes exhausted and 

 succumbs to the weaker but tireless 

 pull of the enemy. When the valves 

 open, the starfish turns its stomach inside 

 out, envelops the soft parts of the prey 

 with it and digests them outside its own 

 body. As soon as this is accomplished 

 the starfish draws its stomach within 

 its body again and immediately starts 

 in search of another victim. Regular 

 armies of starfish march back and forth 

 across the mussel beds and up and down 

 wharf piles and rocks where the mollusks 

 grow, devouring them at a rate which no 

 one has 3'et attempted to estimate. 



The conchs or winkles, Busycon carica 

 and B. canaliculata, also have a keen 

 appetite for the tender Mytilus. The 

 manner of attack is to crawl on top of 

 the victim and patiently wait for the 

 valves to open, when the conch thrusts 

 its own shell between the valves of the 

 prey, introduces its proboscis and with 



365 



