No. 19.] ECHINODERMS OF CONNECTICUT. 33 



as crows and gulls, which frequent the shore, sometimes feed 

 upon the starfish when other food is difficult to obtain. The star- 

 fish is said also to suffer occasionally from the effects of a para- 

 sitic disease. 



But the greatest destruction occurs in the very early stages 

 in the life of the starfish, at the time when the bipinnarise or 

 brachiolarise, as the embryos are termed, are swimming free at 

 the surface of the water. At this time such fishes as the men- 

 haden swim through the water with their mouths widely open 

 and devour countless numbers of small organisms of all sorts 

 from near the surface. Among these may be the young of 

 two species of Asterias, and vast numbers are destroyed in this 

 way. The young of Henricia develop directly from the egg, and 

 thus escape the dangers of the free-swimming stage. 



How does it happen, then, if there be so few natural enemies 

 of the starfish after it has assumed the adult condition, that 

 the sea is not overrun with the creatures to the exclusion of all 

 other animals? Of the thousands of eggs laid by a female 

 starfish each year not more than one on the average produces a 

 sexually mature animal. All the others die ; some are destroyed 

 by the enemies indicated, many die from their inability to obtain 

 food, others are buried beneath the mud of the bottom, some 

 are crushed by the rolling pebbles on the shore, still others 

 succumb to changes in the temperature of the water, many die 

 from the effects of rain or streams of fresh water, while vast 

 numbers are left by the tides to be destroyed by drying in the air. 



As a result of these many hazards only a small fraction of 

 one per cent, of the embryos^ survive to produce young starfishes 

 a half-inch in diameter. The few that '•each this stage of de- 

 velopment are comparatively safe. 



DAMAGE TO OYSTERS AND OTHER MOLLUSKS 



There is little realization except among the oyster planters 

 themselves of the enormous extent to which the starfish is 

 destructive to the oysters and clams which form such an im- 

 portant natural resource of the state. The oyster industry alone 

 produces an annual income of over a million dollars, and 

 furnishes employment to hundreds of citizens. 

 3 



