^^^"^ Jennings. — Behavior of the Starfish. 89 



but there was no further attempt to capture the sea urchin for 

 food. 



In the aquarium the starfish frequently had better fortune 

 in its attacks on certain animals that could hardly be expected 

 to fall prey to it. It seems surprising that the starfish can cap- 

 ture such active, swift animals as fish. But in our tanks this 

 often occurred. They captured and devoured fish having a 

 lent-th equal to the diameter of the starfish, from the tip of one 

 ray to the tip of the opposite one. In one of our tanks a large 

 number of starfish crawled about over the sides and bottom. 

 At times numbers of fish of various sorts were kept in this tank, 

 and it was soon found that the starfish were capturing them. 

 The fish, swinnning about, seemed to have no mistrust of the 

 brown patches on the walls; when frightened they would even 

 attempt to conceal themselves upon or against the starfish. The 

 tail or a fin strikes in its motion the surface of the starfish. At 

 once the rosettes rise, the pedicellariae open, and when the edge 

 of tail or fin comes against them anew, it is seized by a hundred 

 little jaws. Of course the fish gives a leap and attempts to pull 

 away; the jaws hold, the fish struggles, and in struggling strikes 

 other parts of its body against the starfish. Wherever there is 

 a thin edge of fin. tail, or gills, the pedicellariae seize it, and the 

 fish soon finds itself held tightly. Now the tube feet extend, the 

 cruel suckers plant themselves over the smooth surface of the 

 body, and the fish is transported to the mouth. In all cases 

 observed it was the tail that was first brought to the mouth. The 

 lobes of the stomach then come forth, press themselves against 

 the tail and proceed to digest it, though the fish still makes at 

 intervals violent efforts to escape. In the course of six or eight 

 hours the posterior one-fourth of the body of the fish was usually 

 ([uite digested, and the remainder of the fish was dropped. 

 Figures 5 and 6 show photographs of the capture of fish by the 

 starfish. 



Certain interesting differences were observed among different 

 fish as to the danger of capture by starfish. When there were 

 placed in the starfish tank fish that in their normal existence 

 spend their time swimming about in the open water, not coming 

 against .stones or other objects save when they attempt to hide 



